[HN Gopher] I spent a week without IPv4 to understand IPv6 trans...
       ___________________________________________________________________
        
       I spent a week without IPv4 to understand IPv6 transition
       mechanisms
        
       Author : pattyj
       Score  : 167 points
       Date   : 2023-03-06 15:06 UTC (7 hours ago)
        
 (HTM) web link (www.apalrd.net)
 (TXT) w3m dump (www.apalrd.net)
        
       | soebbing wrote:
       | I am quite happy that all those shady IoT devices cannot be
       | reached from the internet directly when I am using IPv4 and NAT -
       | what would be the best way forward to keep it that way in a
       | IPv6-only future?
       | 
       | The best idea I can come up with (at least right now) is: put all
       | less trustworthy (read: Closed source) devices into a special
       | legacy IPv4 network and only use IPv6 on my workstation and
       | little Raspis?
        
         | wolrah wrote:
         | > I am quite happy that all those shady IoT devices cannot be
         | reached from the internet directly when I am using IPv4 and NAT
         | - what would be the best way forward to keep it that way in a
         | IPv6-only future?
         | 
         | The same exact way you do it right now.
         | 
         | Think of NAT as an implicit default-deny firewall rule, that's
         | all it's doing.
         | 
         | Basically any firewall worth using will do exactly the same
         | thing in IPv6, deny unsolicited inbound traffic unless
         | explicitly allowed.
         | 
         | For some reason there's this belief out there that a device
         | having a globally routable IP address inherently means it's
         | globally reachable, and that's just not true. Your firewall
         | still works exactly the same way.
        
           | jiggawatts wrote:
           | Not to mention that 99.99% of IoT devices connect to the
           | mothership using an _outbound_ connection, which is permitted
           | by default on both IPv6 and IPv4+NAT.
        
         | wyager wrote:
         | Put internet of shit devices on their own VLAN(s). Almost all
         | wifi APs today support multiple SSIDs with separate VLANs. Have
         | your firewall block inbound connections to devices on that
         | VLAN. Every OS firewall has built-in support for this.
         | 
         | I spent a lot of time figuring out how to do all this in the
         | most efficient way (in terms of my time and effort) during
         | covid, and I suggest getting any arbitrary box with 2 ethernet
         | ports and putting freebsd on it.
        
           | philjohn wrote:
           | I go one further - the IoT VLAN (Sonos, Philips Hue, wifi
           | controlled light strips, TV's) is hard segmented from my
           | "trusted" VLAN (except for some specific holes punched so
           | things like SSDP and streaming from a media server work).
        
           | soebbing wrote:
           | I actually thought about that for a minute when I set up my
           | home network a while ago, but that seems to be a pretty hard
           | (or at least inconvenient) problem.
           | 
           | Often I need to access a device from my local network (think:
           | use my phone to control Wi-Fi LED Strips, Sonos speakers,
           | etc.), which makes it impossible (I guess?) to separate these
           | devices into their own network completely (if they aren't
           | controlled by an online service in general). Or is it
           | possible to allow access from my trusted network INTO the
           | restricted network, but not the other way around?
           | 
           | Total network noob here, in case you haven't figured that out
           | yet. :)
        
             | wyager wrote:
             | > Or is it possible to allow access from my trusted network
             | INTO the restricted network
             | 
             | Yes, my home network works exactly like this. I have a vlan
             | called "trusted" which can connect to any other vlan. One
             | line in pf.conf.
             | 
             | My VLANs are something like: trusted, guest, media,
             | cameras, printer, etc.
             | 
             | Many of these aren't allowed inbound _or_ outbound
             | connections (e.g. cameras and printer can only talk to
             | things on their subnet).
             | 
             | Only downside is that stuff that works off broadcast
             | packets (like bonjour) does not work across subnets.
        
               | kube-system wrote:
               | There are mDNS repeaters that can in some cases make
               | bonjour work across different networks. In my experience
               | I spend more time fighting with mDNS than I do enjoying
               | it.
        
             | labcomputer wrote:
             | Each of the VLAN is (or can be) just another network from
             | the router's and firewall's perspective. So you just have
             | to set up appropriate firewall rules to allow traffic
             | between the networks that you want to communicate.
             | 
             | You could, for example, allow only TCP traffic initiated by
             | hosts in the "normal" VLAN to hosts the IoT VLAN. So IoT
             | stuff can't initiate outgoing connections to any other
             | network, and can only receive TCP connections from one
             | network.
             | 
             | You can also set up an MDNS reflector on your router if
             | your IoT devices use that (e.g. HomeKit) to send data
             | proactively back to "normal network" hosts.
        
             | throwaway742 wrote:
             | >Or is it possible to allow access from my trusted network
             | INTO the restricted network, but not the other way around?
             | 
             | Yes
        
         | nickstinemates wrote:
         | Network segmentation, i.e use of vlans is the traditional way
         | to solve this.
        
           | Godel_unicode wrote:
           | Not sure why you're being downvoted, this is a very good
           | answer. Maybe because you left out the implied "and then
           | firewall off that vlan"?
        
             | soebbing wrote:
             | Yeah, it seems to be the common consensus to just block
             | everything going in and just make exceptions, where you
             | really want to offer a service to the internet.
             | 
             | Makes total sense, thinking about it. I guess, all those
             | years of just sitting behind a NAT makes one forget all
             | these networking basics if you're not using them regularly.
             | 
             | Moving closed-source IoT devices into a special vlan, with
             | some even more rigid rules (something like: only allow
             | http/https traffic into the internal network) might be an
             | additional level of security.
             | 
             | Thank all of you for your replies!
        
         | screamingninja wrote:
         | It's worth noting that NAT is not a security feature in itself,
         | but rather a way of conserving public IP addresses and hiding
         | the internal network structure. The best way is to use a
         | stateful firewall that is built into nearly every router.
         | 
         | Another option is to use IPv6 Unique Local Addresses (ULA),
         | which are similar to private IPv4 addresses and can only be
         | used within a specific site. This approach enables internal
         | connectivity for devices that do not require direct access to
         | the Internet. I use it for several IoT devices that I do not
         | want reaching out to the mothership.
        
         | adriancr wrote:
         | Although I'm going to get comments saying this is wrong...
         | 
         | What I did was:
         | 
         | - IPv6 DHPC - private address range within: fc00::/7
         | 
         | - IPv6 NAT, same as for IPv4.
         | 
         | - Firewall.
         | 
         | Why:
         | 
         | - digital ocean only allowed ~16 IPv6 addresses.
         | 
         | - I wanted a local IPv6 network exiting through digital ocean.
         | 
         | - I see no reason to give public route-able addresses to each
         | device in my home (allows remote websites to determine who is
         | calling it and set up profiles/target each remote device).
         | 
         | - Sure, privacy extensions which cycle unique addresses, but it
         | still allows profiling based on source address, even if a bit
         | of work is needed for each new addresses.
        
           | Xelynega wrote:
           | Why would your firewall allow your ipv6 IoT devices to
           | receive inbound connections from the internet? Whats the
           | difference between "ipv6 Nat" and a firewall when theres not
           | likely to be any address overlap.
        
             | adriancr wrote:
             | > Why would your firewall allow your ipv6 IoT devices to
             | receive inbound connections from the internet?
             | 
             | It does not, problem is with outbound connections.
             | 
             | > Whats the difference between "ipv6 Nat" and a firewall
             | when theres not likely to be any address overlap.
             | 
             | Outbound connections can be profiled by remote websites.
             | 
             | With NAT (Well... Port-address-translation to be fair, so
             | single outgoing address), traffic can't as easily be
             | profiled.
             | 
             | Imagine ISPs/Ad providers having easier time identifying
             | you, your spouse, your kids, etc. (and device, and so on
             | just by observing addresses)
             | 
             | With initial SLAAC it is even nicer as MAC address is
             | included in the address... Can look up device much easier
             | just cross reference manufacturer database...
        
           | xnyanta wrote:
           | Digital Ocean has horrible IPv6 support, I would just move to
           | another provider. Most VPS providers will, at the very least,
           | provide you with a /64.
        
         | nijave wrote:
         | >cannot be reached from the internet directly
         | 
         | Stateful firewall that allows outgoing connections and blocks
         | incoming (or maybe blocks both)
         | 
         | In general, you probably don't want to allow unsolicited
         | incoming connections to any devices, regardless of IoT.
        
         | cnorthwood wrote:
         | You'd probably do it in the same way you'd do it with NAT, by
         | using a stateful firewall blocking inbound connections (it's
         | just that you get this for "free" with NAT)
        
         | jhoelzel wrote:
         | You can configure your local ipv6 net without SLAAC (Stateless
         | Address Autoconfiguration).
         | 
         | Or differently put, you don't need to use the net your isp
         | provides everywhere, ipv6 can still use NAT if you want it to:
         | https://openwrt.org/docs/guide-user/network/ipv6/ipv6.nat6
        
         | vel0city wrote:
         | > what would be the best way forward to keep it that way in a
         | IPv6-only future?
         | 
         | Firewalls. You configure what traffic should be allowed from
         | who to who. Default deny incoming traffic, and its the same
         | behavior as when you had a NAT.
         | 
         | Something having a routable IP address doesn't mean it needs to
         | receive all traffic addressed to it.
        
           | candiddevmike wrote:
           | The problem I have had with this setup is allowing inbound
           | traffic to things that need it becomes tricky. Some devices
           | don't support DHCPv6 like Android) and some firewalls don't
           | let you do suffix matching. With a dynamic block via PD, the
           | rules to allow inbound traffic to say an Xbox become quite
           | complicated.
        
             | nrabulinski wrote:
             | You can still have a firewall on the router level, just as
             | you do with IPv4. You shouldn't allow any external traffic
             | by default anyway and NAT shouldn't be a security measure.
        
               | candiddevmike wrote:
               | I know, I'm saying that when you want to embrace global
               | routable addresses for outbound AND inbound, it's hard
               | with Prefix Delegation and spotty DHCPv6 support.
               | 
               | ISPs should be forced to let customers get IPv6 prefix
               | reservations. Yes, PD doesn't change for most, but I'd
               | rather not use PD at all.
        
           | groestl wrote:
           | My ISP does not allow BYOM (bring your own modem) and assigns
           | me a /64 net, so I have a hard time running an (ipv6) router
           | behind it that would do the firewalling.. I guess I'm stuck
           | with ipv4 for the time being...
        
             | aaronax wrote:
             | A firewall can be run "in-line" and not have IP addresses
             | on the interfaces. On a Palo Alto firewall this would be a
             | "virtual wire", and "transparent firewall" or "bridging
             | firewall" would be other common terms.
             | 
             | Examples: https://docs.opnsense.org/manual/how-
             | tos/transparent_bridge.... https://docs.netgate.com/pfsense
             | /en/latest/bridges/index.htm... https://www.fortinet.com/re
             | sources/cyberglossary/transparent...
        
               | groestl wrote:
               | Thanks for the hints. Currently, I have a fully routed
               | setup with two routers behind the IPSs box, multiple
               | wireless networks and VPN uplinks (via wireguard) to my
               | servers. It's just that all of this is ipv4, because I
               | don't see any way of doing that using a single /64
               | network.
        
             | throwaway742 wrote:
             | https://www.fortinet.com/resources/cyberglossary/transparen
             | t...
        
             | justeleblanc wrote:
             | Does your ISP's router not have a firewall?
        
               | groestl wrote:
               | A very very inconvenient one.
        
         | samcat116 wrote:
         | Most consumer routers will disable inbound connections for the
         | IPv6 prefix by default from what I've seen. If not thats easy
         | to enable.
        
       | Steltek wrote:
       | > The biggest hurdle to implementing IPv6 on your own isn't
       | usually ISP support, router support, or client support.
       | 
       | I'm fully ready to start using IPv6 but my packets won't get past
       | my antiquated ISP. That seems like a pretty big hurdle, no?
        
       | superkuh wrote:
       | >There seems to be a lack of drive (judging by forum posts) to
       | enable IPv6 on internet services by admins, either because they
       | don't care to, or it's more work to manage a public IPv4 and
       | public IPv6 presence
       | 
       | If you run a mailserver adding ipv6 support is far more risk to
       | your domain's mailserver reputation than it is worth. And if
       | you're just a human person and not a megacorp that new ipv6
       | address, even if it it doesn't immediately hurt you, will take a
       | very long time to get accept, longer than an ipv4.
        
         | dheera wrote:
         | Yeah I have zero motivation to deal with IPv6.
         | 
         | I also have all my IPv4 addresses memorized, and IPv6 addresses
         | are too long to remember with all the hex-double-colon
         | nonsense.
         | 
         | If they could have turned
         | 
         | 1.2.3.4
         | 
         | into
         | 
         | 1.2.3.4.5.6
         | 
         | I'd probably use it, but instead they opted for some scary
         | stuff that looks like
         | 
         | d0ff::eefa::0010::faff:::://::92::0
         | 
         | which I'd rather not look at. Product management fail.
         | 
         | Anyhow, IPv4 still works for me, so I have no pressing need to
         | even try to understand these hex-colon monstrosities.
         | 
         | My DNS server is 8.8.8.8.
         | 
         | Why the hell isn't the IPv6 DNS server
         | 
         | 8888:8888:::8888:8888?
         | 
         | Instead it's 2001:4680::... wtf?
        
           | SoftTalker wrote:
           | Yep I'm in your camp. I have zero problems using IPv4 (and
           | NAT when necessary), unless and until that stops working I'm
           | staying with it.
        
           | hot_gril wrote:
           | I've been saying this too. Don't tell me that going from
           | 8.8.8.8 to :whatever::the::heck:::: is an upgrade.
           | 
           | First step of dual-stack networks should've been, every
           | device's IPv6 address is the same as the IPv4 address, just
           | padded technically, and represented textually the same. If I
           | put in 8.8.8.8 and the systems want to speak IPv6 instead, go
           | ahead. A little hacky but addresses (no pun intended) both
           | technical and marketing problems. You could even use a v4
           | DHCP server and DNS but speak IPv6, instead of trying to sell
           | people on a whole stack change at once.
        
           | zamadatix wrote:
           | : separates groups of 4 while optionally :: abbreviates a
           | bunch of 0's and leading 0's in groups are optional. The
           | address can be longer, sure, but it's really near identical
           | to dotted decimal beyond the lengths.
           | 
           | I wouldn't mind a simpler DNS server IP though seeing as it's
           | one of the few locations you need to treat as an address
           | regularly. Sprint/T-Mobile has 2600::, which is not only
           | short but seemingly a phreaking reference, active so why
           | can't something similar be active for DNS. I get not wanting
           | 8888 or whatnot, those blocks aren't assigned and advertising
           | random bits for vanity can be annoying, but there are plenty
           | of short IPv6 addresses that could be in use for the most
           | common DNS servers on the planet. Even I have my personal DNS
           | server running on an XXXX:XXXX:: public IPv6 address!
        
             | hot_gril wrote:
             | > separates groups of 4 while optionally :: abbreviates a
             | bunch of 0's and leading 0's in groups are optional. The
             | address can be longer, sure, but it's really near identical
             | to dotted decimal beyond the lengths.
             | 
             | Consecutive colons aren't readable or easy to remember.
        
           | bushbaba wrote:
           | The biggest miss of ipv6 was on usability. is a large
           | contributor for the slow adoption.
        
           | Symbiote wrote:
           | If you would like to write IPv6 addresses in the same style
           | as IPv4, they would look something like
           | 208.255.238.250.0.16.239.109.89.54.222.189.74.21.22.9
        
             | dheera wrote:
             | And that's the problem! Who can memorize all that?
             | 
             | I mean look, a few days ago Comcast had an outage and I
             | plugged my phone into my USB port to tether it for internet
             | access. It hijacked my DNS entirely, and I couldn't turn on
             | my damn lights or change my thermostat which were on my
             | LAN. Thankfully I know their LAN IPv4 addresses from
             | memory, 10.10.10.x and 10.10.10.y, and I was able to issue
             | CURL commands directly to their local, non-cloud APIs to
             | manipulate them. With IPv6 hell knows what their hex-colon
             | monstrosities would be.
        
               | hot_gril wrote:
               | I agree with the complaint about IPv6, but in this
               | situation couldn't you just use nmap?
        
               | xnyanta wrote:
               | > With IPv6 hell knows what their hex-colon monstrosities
               | would be.
               | 
               | You would know exactly, because every IPv6-enabled
               | interface has a link-local predictable IPv6 address
               | derived from its MAC address.
        
               | dheera wrote:
               | And so now I have to stick stickers on every light bulb
               | with a huge address on it and then get up on a chair
               | several times per bulb while I transfer chunks of its
               | address from the sticker to my terminal?
               | 
               | The reality is with IPv4 I can memorize all of the IPv4
               | addresses of every light bulb, every robot, every
               | thermostat, every plant watering device in my residence,
               | and I can hammer out CURL commands to control everything
               | almost from muscle memory in the event of a DNS
               | hijacking.
        
               | rahkiin wrote:
               | Seems like a complicated solution to a problem that does
               | not exist. You cannot turn on lights at all without a
               | working network? If your router crashes your whole house
               | is stuck? Seems like there is a bigger issue than the
               | IPv6 protocol
        
               | [deleted]
        
           | voytec wrote:
           | Lazy people like you (opinion based entirely on your comment)
           | are why the world is not moving forward (fast enough). You
           | should not be responsible for administering IT
           | networks/servers/services if you're not willing to adapt to
           | changes.
        
             | dheera wrote:
             | > are why the world is not moving forward
             | 
             | I'm not an IT admin, but I disagree the world is not moving
             | forward.
             | 
             | If I need to use IPv6, I would switch. But the reality is
             | people are able to still build rocket ships, electric cars,
             | and large language models with IPv4. The world is moving
             | forward just fine.
        
             | hot_gril wrote:
             | I hope you're on the new version of everything then, not
             | just in your area of expertise. You're expecting people to
             | want something that's worse for them if anything, and
             | calling them lazy isn't going to help. What would've helped
             | is making IPv6 more user-friendly.
        
               | [deleted]
        
               | voytec wrote:
               | Not new version, but reliable version. I'm not a
               | bleeding-edge fanatic, but I was testing IPv6 during the
               | 6bone[1] phase while networking was not in my scope. It
               | simply made sense to get to know the future.
               | 
               | The person who's comment I was responding to, is in
               | denial 20 years later because they feel comfortable with
               | IP addresses they can remember.
               | 
               | [1] https://en.wikipedia.org/wiki/6bone
        
           | Arnavion wrote:
           | https://news.ycombinator.com/item?id=26615231
        
       | dan1234 wrote:
       | I'd love to embrace ipv6, but my ISP's official line, for as long
       | as I can remember, is 'planning it, details to come'.
       | 
       | I don't expect them to move forward on it until significant sites
       | become ipv6 only as they've admitted that they have more than
       | enough ipv4 addresses for their subscriber base, so there's very
       | little incentive for them to do anything atm.
        
         | tinus_hn wrote:
         | You can request free IPv6 connectivity through the Hurricane
         | Electric tunnel broker at ipv6.he.net
        
           | dan1234 wrote:
           | Thanks, I've actually looked at that in the past, but I'm not
           | sure what their throughput is, and I'd have to configure each
           | device individually as the router I have can't be configured
           | for it.
           | 
           | I think I've still got my HE IPv6 t-shirt somewhere, from
           | when I completed their readiness quiz so years ago!
           | 
           | Edit: I actually decided to set up a tunnel, just to see how
           | well it worked, and it turns out my ISP supplied router won't
           | forward the protocol 41 packets anyway, so that's a total no-
           | go.
           | 
           | I suppose I could probably set up a small VPS and Wireguard
           | vpn, then forward the IPv6 packets that way?
        
             | toast0 wrote:
             | https://route48.org/ provides 6 in 4 tunnels and wireguard
             | is an option. Their webpage is a mess, but more info is
             | available behind the login, IIRC. I got part way through
             | and then decided to just use a Hurricane Electric tunnel
             | because HE has presence at the nearest internet exchange
             | and it was more familiar.
        
         | KomoD wrote:
         | My ISP went "we're planning it", "it's in progress", "we
         | cancelled it", "there's not enough demand", and they're a
         | pretty large ISP in my country.
        
       | bittermandel wrote:
       | Is there any risks of nodes assigning same IP if there's no
       | central DHCP?
        
         | screamingninja wrote:
         | Unlike in IPv4, in IPv6 there is a lower risk of nodes
         | assigning the same IPv6 address if there's no central DHCP.
         | This is because IPv6 uses a unique interface identifier (IID)
         | that is automatically generated by the node based on its MAC
         | address and a random value. This makes it highly unlikely that
         | two nodes on the same network would generate the same IID and
         | therefore, the same IPv6 address.
        
         | ilyt wrote:
         | Not if you don't have same MAC in the network .
         | 
         | SLAAC reserves bottom 64 bits for autoconfiguration, and while
         | incredibly wasteful it does ensure every MAC can have its own
         | IP address
        
         | riobard wrote:
         | Don't worry coz DAD (Duplicate Address Detection) will come to
         | your rescue :p
        
         | p1mrx wrote:
         | You can generate sqrt(2^64) random suffixes before the
         | probability of collision becomes significant. That number is in
         | the billions for a single /64 network.
         | 
         | In other words, no.
        
         | teddyh wrote:
         | Firstly, normally nodes base their automatic IPv6 address on
         | their MAC address, so there will be no conflict between these,
         | since MAC addresses are supposed to be unique to the hardware.
         | Otherwise, it's a random 64-bit number (actually a few less
         | bits, but not many). It's very unlikely a collision will
         | happen. And even if it does, there is a protocol (Duplicate
         | Address Detection) to detect it, and avoid it.
        
       | screamingninja wrote:
       | The IPv6 transition is challenging because it requires
       | coordination and cooperation from many different stakeholders,
       | including site admins, CDNs, network designers, and device
       | manufacturers. However, as the author realized, IPv6 is ready for
       | prime time and offers significant benefits over IPv4. Looking
       | forward to the transition to IPv6 for unlock its full potential
       | for a more secure, efficient, and connected internet.
        
       | j1elo wrote:
       | Microsoft's GitHub Actions (continuous integration) runner
       | machines do not have IPv6, and cannot be used for things like
       | unit tests that require an IPv6 network interface for whatever
       | thing they are testing.
       | 
       | Add that to the list of thousand cuts.
        
       | trabant00 wrote:
       | It's been ~10 years since IPv6 became "ready for prime-time" and
       | I wouldn't touch it unless I absolutely have no other choice. In
       | practice you are going to run into bugs and problems at every
       | level, from client software to the OS networking, your router,
       | your ISP, their ISP, their router, their server and so on and so
       | forth. I absolutely support other people using it to iron out all
       | the kinks, so that I can finally do it without headaches in 10
       | more years.
        
       | somerandomqaguy wrote:
       | I've still got some misgivings about IPv6.
       | 
       | Biggest one for me personally is that my current ISP doesn't give
       | stable prefix. Power outages or firmware updates requiring a
       | router reboot thus can cause the PD to be changed and potentially
       | break firewall rules that are sensitive to the PD. In an absolute
       | worst case, it also means that none of your hosts can reach the
       | internet anymore if for whatever reason they're not updated of
       | the prefix change.
       | 
       | No, the ISP is not supposed to that. But I don't see them
       | changing this behavior any time soon. Yes there are ways to
       | mitigate (ULA, mDNS, DNS, DHCPv6, etc) but now you're introducing
       | additional complexity that didn't exist before into the network
       | when I keep hearing how Ipv6 is supposed to reduce complexity.
       | And IPv6 is complex enough to make my head spin without
       | considering those workarounds.
       | 
       | Other issue I can think of off the top of my head is how to deal
       | with an organization that would requires multi-WAN fail over or
       | load balancing? The only solutions I've see thus far are far
       | beyond my level of skill and budget. I assume also that there's
       | similar problems when asking about a load balancer between
       | multiple gateways to the internet.
        
       | jhoelzel wrote:
       | I have built a couple of dual stack Kubernetes clusters already
       | and they work much better to be honest. Most of the problems are
       | solved and especially for node-based-ranges it works really well.
       | Even in ipv6 only mode calico will manage amazingly and so do my
       | OpenWRT routers.
       | 
       | HOWEVER,
       | 
       | My ISP regularly messes up with its ipv6 routing (deutsche
       | Telekom (so as big as it can get for me) and if that's not the
       | problem, the mesh networks on my (current gen) fritz networking
       | equipment (very widely used in de) eats itself and sometimes just
       | routes my traffic to nirvana.
       | 
       | This is especially bad with online gaming services like xbox
       | live, who for the love of themselves don't have a fallback to
       | ipv4 implemented, once ipv6 drops. "i have an ipv6 so I'm gonna
       | use it no matter what".
       | 
       | Therefore I have dual stack vpns hooked up to my office network
       | which connect to the datacenters I am using. My private network
       | is ipv4 and sadly will remain like that for a while.
        
         | martinald wrote:
         | Yeah I found the same on Hyperoptic in London. Works fine 99.9%
         | of the time, but occasionally ipv6 drops until I restart the
         | router/restart the WAN connection. Which of course I barely
         | ever notice because most stuff switches back to ipv4.
         | 
         | I think unless we start seeing ipv6-only stuff this will be the
         | case, there's really no incentive for a lot of
         | testing/debugging on at least consumer ipv6 connections until
         | stuff actually breaks.
         | 
         | Would be cool if Google added a 'ipv4' warning to Chrome
         | similar to how they do with HTTPS (maybe not as strong though).
         | That would drive a lot of adoption.
        
           | miyuru wrote:
           | > Would be cool if Google added a 'ipv4' warning to Chrome
           | similar to how they do with HTTPS (maybe not as strong
           | though). That would drive a lot of adoption.
           | 
           | You can kinda already do this by setting search to
           | ipv6.google.com
           | 
           | Images search does not work on that domain, looks like the
           | new Google devs don't know about it.
        
         | cooljacob204 wrote:
         | > My ISP regularly messes up with its ipv6 routing
         | 
         | Can you expand on this? I recently upgraded my network to
         | support ipv6 but a big concern I have is what if they (Verizon
         | Fios) change my assigned block? How can I make sure my PI hole
         | and server has the same static IP address?
        
         | xnyanta wrote:
         | I got so fed up with IPv6 being either straight up unavailable
         | or being deployed in a botched fashion by residential ISPs in
         | my area in the last 10+ years that I picked up an ASN and a /44
         | last year. I advertise it from a VM on Vultr in a datacenter
         | close to home and the experience is just amazing.
         | 
         | I also got fed up with people discriminating against Hurricane
         | Electric's tunnel broker (streaming services, etc) so now I
         | just have my own tunnel broker. It's really great to have my
         | own addresses, use them in my kubernetes clusters (via calico
         | and cilium) and have my homelab directly advertised to the
         | internet, knowing I will never need to re-number.
         | 
         | Networking is a helluva drug
        
       | orcajerk wrote:
       | There's a reason most haven't moved to ipv6. ipv6 is a solution
       | looking for a problem. What we really need is an ipv7 that takes
       | the best of ipv4 and ipv6 instead of trying to force ipv6 down a
       | reluctant user group.
        
         | growse wrote:
         | It's not that the reluctant user group doesn't like IPv6, they
         | don't like _change_.
        
         | cornholio wrote:
         | You can't have the best features of the two - in the sense of
         | interoperability - because they are different on a fundamental
         | level: it's impossible for IPv4 nodes to talk to IPv6 nodes
         | without understanding the much larger address space.
         | 
         | There were proposals back in the day (early 90s) for IPng (IP
         | Next Gen, as IPv6 was called back then) to be a hierarchical
         | routing algorithm, that could have kept backwards compatibility
         | with IPv4 and transparently allow seamless operation and
         | routing of IPng islands over IPv4 infrastructure, taking full
         | advantage of the address space expansion.
         | 
         | Think of a sort of CGNAT that instead of stateful hacking with
         | port numbers and the like, would have dedicated fields in the
         | IPv4.x packet, allowing the gateway to statelesly route between
         | the two domains (public IPv4 internet and internal 10.x.x.x
         | network), while maintaining end-to-end connectivity.
         | 
         | Alas, the ITEF guys really wanted a clean slate design and
         | willfully ignored the economic problem, that IPv6 is only
         | useful when everybody upgrades, and as a consequence nobody
         | upgrades. It's probably one of the most costly failures in the
         | history of computing, along with the NULL pointer, 640kB and
         | the likes.
        
       | bityard wrote:
       | Question from a (relative) IPv6 newbie that wasn't addressed in
       | TFA:
       | 
       | Let's say I have a very small home lab. I have a handful of hosts
       | that get their IP addresses via DHCP from my router. In the
       | router, DHCP and DNS are tightly coupled such that the router
       | essentially always knows the MAC address, IP address and hostname
       | of each device.
       | 
       | Now I want to run IPv6 on this network as a first-class citizen.
       | Since DHCPv6 is apparently frowned upon by v6 purists, and not
       | all devices on my network support it, that leaves SLAAC. My
       | understanding of SLAAC is that each node essentially picks its
       | own globally unique IP instead of asking a router for the IP. My
       | question then is: is there some standard for the DNS server on
       | the router to somehow know the v6 IPs of the hosts on the network
       | so that it can automatically create the right A records?
        
         | unethical_ban wrote:
         | Can't answer your main question, but from what I recall, DHCPv6
         | is kind of necessary anyway. It's the easiest/main way for the
         | client to receive DNS server information, even if default
         | gateway discovery is now down through multicast.
         | 
         | I believe there is another way, but the router has to support
         | it and I forget what it's called.
        
           | jesterpm wrote:
           | RA (Router Advertisement) handles announcing the prefix for
           | SLAAC addresses and DNS.
        
             | magicalhippo wrote:
             | But not other services like NTP, so DHCPv6 is still needed.
        
               | Arnavion wrote:
               | For NTP, an alternative is letting the LAN devices
               | connect to whatever NTP server they want to, and just
               | NAT'ing outgoing udp/123 to your NTP server.
        
               | magicalhippo wrote:
               | Well yes, but that's a suboptimal hack.
        
             | vetinari wrote:
             | yes, but RDNSS is a relatively new option (only since 2007
             | ;) ), so some implementations ignore it.
        
         | dmm wrote:
         | It's important to distinguish between stateful and stateless
         | DHCPv6. stateless DHCPv6 is fine. It's just a way for nodes to
         | get dns/ntp/etc. Nodes still select their addresses with SLAAC.
         | 
         | Stateful DHCPv6 is the bad one. It assigns hosts specific
         | addresses.
         | 
         | > the router essentially always knows the MAC address, IP
         | address and hostname of each device.
         | 
         | You can still have this with ipv6 addresses. They easiest way
         | is to use eui64, the original ipv6 addressing scheme where the
         | address is calculated from the subnet + the MAC address of the
         | interface. That way server VMs get deterministic addresses. If
         | you use network-manager you can configure eui64 with the "add-
         | gen-mode=eui64" setting.
         | 
         | In my homelab, I have a few server VMs that use eui64
         | addressing whereas the end user devices use privacy addresses
         | randomly selected from the subnet.
        
         | Latty wrote:
         | It isn't really true that DHCP and DNS are coupled, it's just a
         | common feature for power user routers as it's convient.
         | 
         | There are options for IPv6: PFSense, as an example, has
         | "Assisted" RA mode where devices can use SLAAC or DHCPv6, so
         | you have SLAAC for general clients that don't need more (e.g:
         | phones that don't support DHCPv6), but clients that want more
         | can use DHCP to provide specific reserved addresses and DNS
         | names, etc...
        
         | Arnavion wrote:
         | >Since DHCPv6 is apparently frowned upon by v6 purists, and not
         | all devices on my network support it, that leaves SLAAC.
         | 
         | It's not a dichotomy between DHCPv6 and SLAAC. You can hard-
         | coded addresses too. Since it's your homelab you presumably
         | already know all the devices that will be connected. It's what
         | I do.
         | 
         | You may not even need to hard-code the prefix everywhere. Eg
         | with systemd-networkd you can configure the device as:
         | [Network]         IPv6AcceptRA=yes         [IPv6AcceptRA]
         | Token=static:::1:2:3:4
         | 
         | ... which will give that interface the address $prefix::1:2:3:4
         | based on whatever $prefix was advertised by radvd. So the only
         | place where you'd need to hard-code $prefix is in your DNS
         | server.
         | 
         | >My question then is: is there some standard for the DNS server
         | on the router to somehow know the v6 IPs of the hosts on the
         | network
         | 
         | NDP discovery (`ip -6 neigh show`) will let you know about
         | other IPs (and corresponding MAC addresses) on the link. It
         | won't do anything for matching them up to DNS names.
        
         | samcat116 wrote:
         | In what way is DNS and DHCP tightly coupled? Automatically
         | creating A records for DHCP hosts is not normal in my
         | experience, especially for consumer routers. If some device
         | your using supports this it could work for IPv6 as well as
         | devices will broadcast on the network for routers when using
         | SLAAC I believe.
        
           | vetinari wrote:
           | Many home devices use dnsmasq as their DHCP server and DNS
           | resolver, and it can optionally use hostnames from the DHCP
           | part of its business during resolving DNS too.
           | 
           | The point GP had that it won't work, then DHCPv6 is not used.
        
         | justeleblanc wrote:
         | It's not usual for your router to create A or AAAA records for
         | the hosts connected to it. Look into Multicast DNS.
        
           | jacob019 wrote:
           | Maybe not, but it's super convenient and well supported by
           | isc-dhcp-server/bind9. I do it on all my networks.
        
         | throw0101c wrote:
         | > _Since DHCPv6 is apparently frowned upon by v6 purists, and
         | not all devices on my network support it, that leaves SLAAC._
         | 
         | The main hold out against DHCPv6 is Android:
         | 
         | * https://issuetracker.google.com/issues/36949085
        
           | mixdup wrote:
           | that thread is amazing. Google's stance makes me want to
           | deploy DHCPv6 simply to spite them. I guarantee in 10 years
           | when some Fortune 500 company or top 20 research university
           | IT department, who has no idea about that thread, goes live
           | with a DHCPv6-only IPv6 stack because it's very similar to
           | their IPv4 network, and 30,000 users can't join their Android
           | devices to the campus wifi, this attitude _will_ change
        
         | vetinari wrote:
         | There is not really an equivalent for what dnsmasq does.
         | 
         | I ended up with bind and rfc2136 dynamic updates. Not all
         | devices are capable of doing it, but it is what Active
         | Directory does by default.
        
         | jacob019 wrote:
         | I have a similar setup. I wouldn't say that DHCPv6 is frowned
         | upon, it works quite well and is the only way to automatically
         | add client hostnames to the local name server. I use both SLAAC
         | and DHCPv6 mainly because Android refuses to support DHCPv6,
         | but I don't need to refer to my phones by hostname anyway.
        
           | joshspankit wrote:
           | I'm in a similar spot as the OP, and one thing that is
           | important to me about knowing the hostnames is that defining
           | (then tracking) a hostname is the only universally-
           | implemented method that lets me scan through the hosts on the
           | network and understand what they all are.
           | 
           | - I'm never going to remember MACs
           | 
           | - Even when IPs are carefully thought out, if something
           | happens to the DHCP server and it needs to be rebuilt, IP no
           | longer tells you anything about what device it is
           | 
           | Whereas hostname/DHCP client name shows up in almost every
           | router UI, is viewable from any *nix machine on the network
           | (when DHCP and DNS work together), and is typically a first-
           | class citizen in the DHCP lease settings themselves. Super
           | handy. As a side bonus: rogue hostnames are immediately
           | obvious, but rogue MACs or IPs require investigation before
           | you know whether they are benign.
        
         | ectospheno wrote:
         | If I want to connect to something by name then I setup a
         | wireguard connection with a fixed ip. The few things that don't
         | allow for that all use mdns anyway.
        
         | kenada wrote:
         | The way I handle this on my home network is to advertise a ULA
         | prefix in addition to the one delegated by my ISP. The ULA
         | addresses are not routed. They're just used for my network. My
         | home DNS server advertises AAAA records using the stable, ULA
         | addresses for those servers I want to advertise. For other
         | machines (like computers, laptops, etc), I rely on mDNS.
        
       | saul_goodman wrote:
       | "Apple has excellent IPv6 support on their devices, fully
       | supporting automatic configuration of 464XLAT on devices with
       | NAT64, and overall an excellent attitude to forcing IPv6 support
       | from developers"
       | 
       | Other operating systems are bit of hit or miss"
       | 
       | My iPhone works, what's wrong with the rest of you for not doing
       | this??!!
       | 
       | But in all seriousness, I think this will be a security nightmare
       | for quite a while if there is some forced conversion to ipv6. I
       | realize IPv6 wasn't created yesterday, but I assume it's got
       | plenty of security holes waiting to be discovered until I see
       | otherwise. The only way you are going to see it be used by end-
       | users is if the various *nix distros roll out IPv4-less images.
       | Same for Windows/etc. Otherwise you are begging for a security
       | nightmare of epic proportions with software that is accidentally
       | using the wrong stack by default, firewalls not filtering
       | anything as expected, etc.
       | 
       | And who thinks it's a good idea to make all the things globally
       | accessible? It's an internet of shit out there already, this
       | would make it even worse.
        
       | skywhopper wrote:
       | From my POV, IPv6 overshot and tried to solve too many non-
       | problems while addressing the only real issue with IPv4, the
       | address space. That fact alone explains the relentless failure to
       | adopt IPv6, because it's not just a matter of adopting IPv6.
       | Nearly every assumption about networking changes, all the tooling
       | is different, and the risks and concerns are all changed. There
       | was an easier path to follow, but we missed that chance 20 years
       | ago, and now we're likely stuck with a dual stack mess for the
       | rest of our careers.
        
       | 1970-01-01 wrote:
       | My #1 gripe with IPv6 is that it is too big. You never ever will
       | use all the octets.
        
         | justeleblanc wrote:
         | That's pretty much the whole point.
        
         | xnyanta wrote:
         | You will use the octets when you find out how useful they are
         | to build a structured addressing plan.
        
       | TekMol wrote:
       | I still think IPv6 can be safely ignored.
       | 
       | This articles section "here are some reasons you should start
       | using IPv6 within your own network" seems to comfirm this. None
       | of the 6 "reasons" speak to me.
        
         | mgbmtl wrote:
         | Here's an easy one for you: if you have a gigabit connection,
         | most home routers can barely handle the load of NAT. That's why
         | gamers push for IPv6. It's mentioned in the article but few
         | people realize how inefficient NAT can be at gigabit and more.
         | 
         | My ISP router could do max 800 mbps, which isn't so bad, but it
         | degraded when we were multiple people using the link. With IPv6
         | it's much less of a problem, we can easily saturate the 1gbps
         | without the router having a meltdown.
        
           | AnIdiotOnTheNet wrote:
           | > if you have a gigabit connection
           | 
           | Rare in the US. Hell, we don't even have a 1Gb connection at
           | work.
        
           | TekMol wrote:
           | I don't even know what type of connection I have. I only know
           | the speed is way more than I need.
           | 
           | fast.com says 50 "Mbps". Whatever that is.
        
             | jaywalk wrote:
             | You aren't qualified to speak on this topic. Sorry.
        
           | favaq wrote:
           | >Here's an easy one for you: if you have a gigabit
           | connection, most home routers can barely handle the load of
           | NAT.
           | 
           | [citation needed]
           | 
           | >That's why gamers push for IPv6.
           | 
           | [citation needed]
        
           | jonathantf2 wrote:
           | I have a symmetrical gig connection, ISP doesn't provide
           | IPv6. Can route full line speed using their router, no matter
           | if it's 1 device or 50 connected.
           | 
           | I don't know of a single game that supports IPv6, although
           | some consoles might?
        
           | lxgr wrote:
           | > if you have a gigabit connection, most home routers can
           | barely handle the load of NAT.
           | 
           | I remember reading about this as well. Wouldn't that also
           | apply to stateful firewalling, though? Or is NAT inherently
           | more computationally difficult (e.g. due to having to
           | recompute IP and/or TCP/UDP checksums) than checking a state
           | table?
        
           | layer8 wrote:
           | > if you have a gigabit connection
           | 
           | Yeah, not anywhere close. In ten years I'll have one maybe.
        
           | wankle wrote:
           | > if you have a gigabit connection, most home routers can
           | barely handle the load of NAT
           | 
           | We are on AT&T Fiber, the router has no issues. I've never
           | seen a router have issues with any speed for that matter,
           | where NAT is concerned.
           | 
           | > That's why gamers push for IPv6.
           | 
           | I'm a gamer, I know a lot of gamers, no one is pushing for
           | IPv6 that I'm aware of.
        
       | [deleted]
        
       | thesuitonym wrote:
       | Everyone always goes with the "You don't need NAT, everything is
       | globally routable!" argument, as if that's something that anybody
       | wants. Everything on my network is going to go through my
       | firewall anyway. I don't _want_ anything on my network to be
       | globally routable.
       | 
       | Of course, this is not a good reason to not use IPv6, don't get
       | me wrong. It's a problem that's easy to overcome, I just think
       | it's not a good way to get people excited about the transition.
        
         | jcalvinowens wrote:
         | There is no downside to everything to be globally routable.
         | It's completely orthogonal to firewalling.
         | 
         | What is the risk you're picturing here? I'm really curious.
         | Features like RFC4941/8981 mean nobody can infer anything about
         | your network from the source addresses they see making requests
         | out if it.
         | 
         | If you want to use link-local V6 addresses and NAT to a global
         | one, you can do that. But IMHO that's sacrificing one of the
         | greatest advantages of IPv6 for no tangible benefit.
        
           | adriancr wrote:
           | > nobody can infer anything about your network
           | 
           | They can infer that one IPV6 address matches to exactly one
           | device. (reverse is not true, one device may have multiple
           | addresses per privacy extensions)
           | 
           | Once device is identified all its past traffic is
           | discernible.
           | 
           | Changing addresses means identification needs to be done
           | again but once done it can be associated with past addresses
           | and again, all its history is visible.
           | 
           | Identification might just mean querying a data broker with
           | HTTP headers.
           | 
           | NAT does not have this issue.
        
             | jcalvinowens wrote:
             | > They can infer that an address matches to a single device
             | 
             | No they can't: the whole point of RFC4941/8981 is to
             | prevent that. The source address for external connections
             | is effectively randomized.
             | 
             | All that can be inferred is that it came from your network,
             | but even with NAT you know that anyway.
        
               | adriancr wrote:
               | > The source address for external connections is
               | effectively randomized
               | 
               | It's still unique to one device right?, even if random my
               | argument still holds.
               | 
               | Or do you mean to say multiple devices can use the same
               | address?
               | 
               | note: I've read the RFCs and they just mean - initial
               | address is random but unique to a device. Each day the
               | address will likely change but new address is still
               | unique to the device (otherwise how would routing work).
               | 
               | This is what I structured my inital argument on. Do you
               | see any fallacy in logic?
        
               | throw0101c wrote:
               | > _Each day the address will likely change but new
               | address is still unique to the device (otherwise how
               | would routing work)._
               | 
               | If you set up your device to spin up a new IPv6 address
               | every hour (or even every minute), how will they track
               | you using IPs?
               | 
               | On macOS it's 24h, but it doesn't have to be:
               | $ sysctl -a | grep temppltime
               | net.inet6.ip6.temppltime: 86400
        
               | adriancr wrote:
               | I mean, it's the same point, single address to single
               | node, just more often, so need to identify more often.
               | 
               | Minutes or less I guess would defeat tracking, but then
               | what's the point?, it's almost equivalent to NAT it still
               | breaks reverse connectivity? and does it actually work?
               | 
               | It also feels like a workaround for an oversight.
        
               | throw0101c wrote:
               | > _I mean, it 's the same point, single address to single
               | node, just more often, so need to identify more often._
               | 
               | But how would they know it is to the same node?
               | 
               | I have my DSL router-modem reboot every night, and I get
               | all sorts of crazy results for ads: I'm in southern
               | Ontario, as is my ISP, but they service folks in Quebec,
               | and so sometimes I get Youtube ads in French since (per
               | my IP) I'm "in" Quebec.
               | 
               | Similarly with the reboot I get a new /64 prefix
               | delegation (actually /56), so I would hazard to guess if
               | IPv6 starts getting tracked, I'd get the same crazy
               | results.
        
               | justeleblanc wrote:
               | You literally wrote "Once device is identified all its
               | past traffic is discernible." How is that compatible with
               | devices changing their address every day?
        
               | adriancr wrote:
               | you identify device each day, identity is X, daughter of
               | Y on iPad. Once identified via data broker all its
               | traffic is identifiable including torrents for example
               | and porn websites, etc (say X goes to facebook with new
               | address it now has real name)
               | 
               | Once identity is known for address X you know its traffic
               | for the day, including past traffic for the day.
               | 
               | once address changes you do the whole identification
               | again.
               | 
               | All these logs where address is identified goes to bucket
               | X.
               | 
               | On addresses where you couldnt identify that day you put
               | them in unknown bucket.
               | 
               | Once you have a profile of the network, you can do
               | exclusion (Only 4 people in household, 3 active with
               | known addresses, not X, one unknown address, you can
               | assume its X)
        
               | jiggawatts wrote:
               | Nobody bothers to do this kind of tracking because web
               | browsers leak 100x more information by default anyway.
               | 
               | The "I don't care if they track my _household_ but it's
               | critical that Daddy's activity not get disambiguated from
               | my dealing daughter" is just not a valid reason to
               | abandon the benefits of IPv6.
               | 
               | Please stop with this line of argument.
               | 
               | If you're really desperate to ensure that the ads shown
               | to your daughter are based on your porn viewing habits,
               | then just set up IPv6 NAT.
        
               | adriancr wrote:
               | > Nobody bothers to do this kind of tracking because web
               | browsers leak 100x more information by default anyway.
               | 
               | That's a broad assumption, and I can assure you they will
               | due to lower costs (no need to pay data broker if you
               | already know target, no need for extra traffic, load,
               | etc). Also due to better targetting you get better prices
               | per ads served.
               | 
               | > just not a valid reason to abandon the benefits of IPv6
               | 
               | What are the benefits to allow each device its own
               | address if I'm going to firewall them anyway?
               | 
               | > Please stop with this line of argument.
               | 
               | Why?, my concern is valid, all you've said so far is
               | nobody cares. I disagree.
               | 
               | > If you're really desperate to ensure that the ads shown
               | to your daughter are based on your porn viewing habits,
               | then just set up IPv6 NAT
               | 
               | That says a lot about yourself if you resort to this sort
               | of snarky comments, I have no wish to continue this
               | conversation.
               | 
               | Note: I said in another comment I have set up IPv6 NAT
               | and it works great.
        
               | wankle wrote:
               | Thank you adriancr, barkingcat and flangola7 for making
               | the salient points about IPv6. When I've tried to make
               | the same points over the years, it didn't work out well.
               | I see there's a new topic today, someone "outraged" that
               | Roku devices don't use IPv6. It's always like that,
               | people who seem to want to heavily push IPv6 are so
               | outraged. All that does is confirm my view of IPv6 is
               | right.
        
               | flangola7 wrote:
               | > Nobody bothers to do this kind of tracking because web
               | browsers leak 100x more information by default anyway.
               | 
               | If I told my security information officer "We don't
               | protect against foreseeable threat X because we assume no
               | one will bother to try X" she would not be very happy
               | with me.
               | 
               | When a valid data concern has been expressed and
               | described, putting your head in the sand is the incorrect
               | response. I want IPv4 to die as much as the next person
               | but at a minimum organizations such as hospitals and
               | government installations will not accept that sort of
               | outside visibility into their network.
        
               | barkingcat wrote:
               | wait ... when you say nobody bothers ... that's a high
               | bar. Most likely a ton of adtech companies are just
               | drooling to use (or already are using) this type of
               | correlation even if browsers leak more info.
        
           | thesuitonym wrote:
           | I'm not saying there's any downside, I'm just saying it's not
           | the magic bullet "this is why you should use ipv6" that
           | everyone seems to think it is. It's a complete non-issue that
           | nobody really cares about.
        
             | jcalvinowens wrote:
             | > It's a complete non-issue that nobody really cares about.
             | 
             | Huh. IMHO it's the single most desirable feature, and the
             | only reason I care about it at all.
             | 
             | If you're approaching this from the home networking point
             | of view, than I suppose I agree: even the most complex home
             | network is just too simple for anything like this to matter
             | much.
             | 
             | As the network gets bigger, that sweet sweet global
             | routability starts to make a lot of things a lot simpler...
             | I'm lucky to have worked on an enormous deployment of
             | V6-only servers, and it's downright magical in comparison
             | to anything of comparable scale I've seen before or since.
             | 
             | But yes, my home network is three NAT'd /24's because I'm
             | too lazy to figure out how to make prefix delegation
             | work...
        
               | kazen44 wrote:
               | Also, IPV6 has far more scalable systems for dynamic
               | address allocation compared to IPv4.
               | 
               | SLAAC scales really, really well, and is fairly stateless
               | compared to DHCPv4 or V6.
               | 
               | Also, slaac allows one to easily change the global prefix
               | of a vm/host if it lives on another layer 3 network.
               | 
               | A good example of this:
               | 
               | you have two seperate datacenter networks based on an
               | EVPN-VXLAN solution, and you do no want to stretch layer
               | 2 across both datacenters because stretching layer 2 is a
               | terrible, terrible idea[0].
               | 
               | Before IPv6, moving VM;s across datacenters which have
               | different public ip space was a major pain for two
               | reasons:
               | 
               | - IPV4 has no concept of using multiple addresses per
               | interface without it having unexpected bahaviour on a
               | host. - address management at scale is a major PITA
               | because DHCP is not scalable.
               | 
               | How to solve this with IPv6? It's fairly easy:
               | 
               | - Use slaac + prefix delegation of your globally unique
               | address space (which is different per Datacenter). - Use
               | a different (site local) address to reach the VM for
               | management purposes. Because this address is not globally
               | routable, you are sure it will never leak into the
               | greater internet and be reachable from the outside world.
               | - If you are using anycast, you can easily announce this
               | prefix to upstream BGP neighbours because you can use BGP
               | Neighbour Autodiscovery[1].
               | 
               | Trying to do this with Ipv4 will result in a mess of
               | administration, not to mention have to do some clever
               | technical hacks to make it work on some operating
               | systems.
               | 
               | With IPv6 solving these issues becomes quite manageable.
               | 
               | [0] https://blog.ipspace.net/2021/06/stretched-vlan-
               | define-probl... [1] https://www.juniper.net/documentation
               | /us/en/software/junos/b...
        
             | growse wrote:
             | The point is that it gives you options. You might not want
             | to have anything on a network reachable from the internet
             | today, but next year you suddenly need that capability and
             | it's useful to be able to take advantage of that, rather
             | than wading through the buggy mess of NAT.
             | 
             | > It's a complete non-issue that nobody really cares about.
             | 
             | A significant number of people spend a significant amount
             | of time trying to carve out and re-use address space in
             | their existing IPv4 allocations and RFC1918 space. This
             | becomes nightmarish the moment you start thinking about
             | networks of any significant size and complexity. All of
             | these problems go away with IPv6, and we care about that a
             | lot.
        
             | throw0101c wrote:
             | > _It 's a complete non-issue that nobody really cares
             | about._
             | 
             | The availability of IPv4 addresses is something that more
             | people will care about, and getting IPv6 going may help
             | folks. From another comment in this sub-thread:
             | 
             | > _I 've actually run into this [CG NAT] helping a friend
             | host a game server on their residential internet in a more
             | rural part of Texas. They had to call their ISP and request
             | a static IP address at an extra cost of something like
             | $5/mo._
             | 
             | * https://news.ycombinator.com/item?id=35046929
        
         | audunw wrote:
         | > as if that's something that anybody wants.
         | 
         | Of course I do. Why would you not want the option of easily
         | allowing a device to be globally routable if you need it to be?
         | 
         | I think routers should be more explicit about how you set up
         | each new device on a private network anyway. Guest wifi can
         | have a sane default. Private wifi could make a notification pop
         | up on your trusted device, asking you if you want the now
         | device to have access to the internet, and if the internet
         | should have access to the device, and if so, which
         | subnets/countries should be able to access it through which
         | ports.
        
           | aflag wrote:
           | Most people don't need it, so that's why they don't want it.
           | OP didn't say people object to it, just that it's not
           | something most people cares about.
        
         | ArchOversight wrote:
         | That's what a firewall is for, NAT does nothing here.
        
           | thesuitonym wrote:
           | I know, did you read my whole post?
        
             | dale_glass wrote:
             | It just makes little sense.
             | 
             | With IPv6 instead of NAT deciding that port 2000 maps to
             | 192.168.1.3 port 22, you have a firewall that may or not
             | choose to route to xx:yy:zz or not, and to allow an
             | incoming connection over port 22 to that host or not.
             | 
             | If you don't want to accept incoming connections to a given
             | machine or network on IPv6 without NAT that's very easy to
             | have.
        
               | AnonymousPlanet wrote:
               | Maybe people don't want to disclose the number and
               | purposes of interior machines?
        
               | silon42 wrote:
               | Yeah, I had an idea to have an IP for each container
               | (which means almost every "containerized" application
               | soon, possibly even every browser window).
        
               | dale_glass wrote:
               | That's what the privacy extensions are for. You can have
               | a regularly changing, randomly generated IP address on
               | each machine.
        
               | justeleblanc wrote:
               | Your machines could change their IPs for every second of
               | every day and you wouldn't come close to exhausting your
               | /64 subnet for the next billion years.
        
               | TheLoafOfBread wrote:
               | Why do network stuff easy, when you can do it hard.
        
               | [deleted]
        
               | petertodd wrote:
               | IPv6 has so many addresses that the default is for /64
               | subnets to be the minimum network size, allowing devices
               | to choose their addresses randomly within that range. If
               | they do that, 2^64 is big enough that it's not practical
               | to enumerate all devices on a given network. Attempting
               | to do so would be a bandwidth DoS attack: attempting to
               | ping 2^64 devices requires 2^64 * 64 bytes = 1024EiB,
               | roughly equal to total global internet traffic per year.
               | 
               | Now, sometimes NAT is needed anyway: QubesOS supports
               | IPv6 using NAT because it splits things up into many
               | different VMs on one computer. But that's a pretty rare
               | case.
        
               | drbawb wrote:
               | EUI64 means that random space is effectively reduced to
               | just 48-bits of real entropy, <40 bits if you start
               | making assumptions about device vendors. For example
               | maybe the attacker has a VMWare exploit: enumerating that
               | OUI (00:50:56) leaves them with just 24-bits of address
               | space to scan, a measly 1GiB of traffic.
               | 
               | It's security through obscurity at best, i.e: not
               | security. You shouldn't be relying on size of address
               | space to protect you from anything. An IDS/IPS that
               | alerts on abnormal ICMP behavior will be useful whether
               | an attack is 1GiB of traffic in size or 1024EiB of
               | traffic in size. (Also you don't even need automated
               | scanning to find some juicy targets: I've seen a lot of
               | routers on the edge of a prefix configured at ::1/64 and
               | ::2/64 for instance.)
        
               | temp2022account wrote:
               | To be fair that info is already available w/ port
               | sequence analysis, the same machine will pick from the
               | same set of ephemeral ports for outgoing connections. I'd
               | say the time for vanity privacy arguments is over, I'm
               | all-in for team globally routable addresses w/ firewalls
               | just saying "yes" or "no" to connections instead of
               | routers guessing at port mappings.
        
               | waych wrote:
               | Port sequence analysis is stifled by SNAT though.
        
               | adriancr wrote:
               | > the same machine will pick from the same set of
               | ephemeral ports for outgoing connections.
               | 
               | Ports on router are allocated by it and not client
               | machines. So far my experience has been they're usually
               | sequential without any preferrence.
        
           | IshKebab wrote:
           | In theory, sure. In practice firewalls can be misconfigured.
           | NAT doesn't have that problem.
        
             | op00to wrote:
             | Consumer NAT firewalls have uPnP enabled, right?
        
             | Arnavion wrote:
             | The amount of firewall config I have to write to let an
             | incoming connection cross from WAN to LAN is the same
             | regardless of whether it goes to a NAT'd IPv4 address or to
             | an IPv6 address.
        
               | [deleted]
        
             | justeleblanc wrote:
             | NAT cannot be misconfigured? Really?
        
               | joshspankit wrote:
               | Not without being entirely broken. I think you might be
               | bringing in uPnP, DNZ, and other such features. NAT
               | itself is more basic.
        
               | buzer wrote:
               | One could argue that if e.g. FTP is not working behind
               | the NAT then the NAT is misconfigured. NAT needs to aware
               | of certain protocols so that it can modify the
               | application layer data.
               | 
               | Of course, if the protocol added workaround for NAT and
               | NAT is modifying that application layer data then it can
               | cause another set of issues.
        
               | lxgr wrote:
               | Unconfigured/not activated firewalls usually fail
               | reachable; without explicit port forwarding or exposed
               | hosts, NATs fail unreachable.
        
               | wolrah wrote:
               | > Unconfigured/not activated firewalls usually fail
               | reachable
               | 
               | Local firewalls on devices, maybe, but network firewalls
               | generally are default-deny on untrusted interfaces, and
               | between 0 and 1 interfaces are trusted by default.
               | 
               | Back in 2007 Apple's Airport Extreme Base Station shipped
               | with a firmware that defaulted to allowing all IPv6
               | traffic, which was quickly pointed out in the tech media
               | and fixed in a patch a few months later. A few of the
               | garbage pile combo modem/router devices distributed by
               | ISPs have had similar issues over the years as well.
               | That's not normal behavior though, when it's observed
               | it's rightfully considered a security flaw and tends to
               | get the kind of attention vendors don't want.
               | 
               | If you know of a mainstream device that would "fail
               | reachable" as you claim here, name and shame please.
               | 
               | > without explicit port forwarding or exposed hosts, NATs
               | fail unreachable.
               | 
               | I work in VoIP and can say from plenty of direct
               | experience this is not true. In the modern work from home
               | era I've had to deal with a lot of the aforementioned
               | garbage pile consumer devices and a recurring issue with
               | some of our clients who had older phones is that their
               | users' home routers did the laziest NAT possible and
               | literally just opened a two way hole on port 5060 (SIP)
               | so as long as the phone was communicating with our server
               | and keeping the pinhole open * _ANY*_ other traffic that
               | hit port 5060 was also sent to the phone, which meant
               | they got all kinds of  "phantom calls" from bots looking
               | for unprotected SIP relays.
               | 
               | Newer phones generally have an option to only accept SIP
               | messages from trusted servers, but older ones sometimes
               | don't so when combined with badly implemented NAT that
               | happens.
               | 
               | And yea, obviously that's a consequence of a particularly
               | bad NAT implementation, but your complaint is about an
               | issue that would only occur in a particularly bad IPv6
               | implementation.
        
             | [deleted]
        
         | lxgr wrote:
         | > Everything on my network is going to go through my firewall
         | anyway.
         | 
         | Yes, and that's a very reasonable configuration.
         | 
         | But UDP hole punching (very widely used for VoIP, online gaming
         | etc.) works orders of magnitude better with IPv6 than with
         | IPv4, since there is no address and port translation to worry
         | about.
         | 
         | With IPv4, it's very hit or miss, since it depends on both
         | sides' NATs and also requires additional infrastructure (i.e.
         | STUN discovery servers).
        
           | throw0101c wrote:
           | > _With IPv4, it 's very hit or miss_ [...]
           | 
           | It's also probably impossible if you're with an ISP that does
           | CG NAT.
        
             | alyandon wrote:
             | I've actually run into this helping a friend host a game
             | server on their residential internet in a more rural part
             | of Texas. They had to call their ISP and request a static
             | IP address at an extra cost of something like $5/mo.
        
               | philjohn wrote:
               | At that point, would a cheap VPS not work instead?
        
               | birdman3131 wrote:
               | No. Game servers usually want high clock speed.
        
               | op00to wrote:
               | You'd just use the VPS as a proxy with a publicly
               | accessible IP, and tunnel the connection back to your
               | home. That would add latency that might be undesirable
               | for a game, but maybe not.
        
               | throitallaway wrote:
               | Unless you're playing something like a turn based game,
               | adding latency/hops is almost never desirable. Every
               | multi-player game that I play is latency sensitive (and I
               | don't play FPS games.)
        
               | alyandon wrote:
               | The server in this case was the PC version of ARK which
               | nom nom noms all the CPU/RAM.
        
         | throw0101c wrote:
         | > _Everything on my network is going to go through my firewall
         | anyway. I don 't want anything on my network to be globally
         | routable._
         | 
         | Globally routable [?] globally connectible.
         | 
         | Your (stateful) firewall will still by default block any
         | incoming connection attempts if they are not replies to an
         | initial outgoing connection. It's just that it will no longer
         | be necessary to go through the rigamarole of STUN, TURN, ICE,
         | etc, that goes along with non-global addresses:
         | 
         | *
         | https://en.wikipedia.org/wiki/Traversal_Using_Relays_around_...
         | 
         | Your end-user device knows its address and the address of the
         | other connection point, and can tell the firewall to open a
         | rule between only those two IPs:
         | 
         | * https://en.wikipedia.org/wiki/Port_Control_Protocol
         | 
         | * http://www.upnp.org/resources/documents/AnnexA-IPv6_000.pdf
         | 
         | Further, because you don't have only one external IP, you don't
         | have to futz around with non-default ports if you want multiple
         | instances of the same service (e.g., Minecraft), because each
         | instance can have its own IP.
         | 
         | Further, if you want certain devices to not able to get
         | outside: (a) give them static assignments and block them at the
         | firewall, (b) don't give them a default route so they are
         | subnet-local, or (c) give them site-local addresses via ULA and
         | do not set up NTPv6 translation.
        
           | gxt wrote:
           | How does that protect privacy of the private network? I don't
           | want to divulge any information about internal topology.
        
             | adgjlsfhk1 wrote:
             | what do you mean by topology? the only information leaked
             | would be the number of computers making requests.
        
               | Faark wrote:
               | And what computer is making what requests. Now that i
               | think about it, this cloud be the reason why youtube
               | started making recommendations based on stuff i just
               | watched in private browser tabs...
        
               | CaliforniaKarl wrote:
               | That's a very strong claim to make. I'd appreciate if you
               | could provide a source to that statement!
        
               | throitallaway wrote:
               | Look at what Android does with MAC address randomization
               | on wireless networks. We will probably see something
               | similar with IPv6.
        
               | lloeki wrote:
               | that's not even true with slaac temporary (a.k.a privacy)
               | or secured addresses.
               | 
               | the only thing you'd "leak" is the prefix, which is no
               | different than a IPv4 WAN address that you'd get with a
               | v4 NAT.
        
               | gxt wrote:
               | * * *
        
         | tenebrisalietum wrote:
         | > I don't want anything on my network to be globally routable.
         | 
         | Then... don't route anything on your network.
         | 
         | NAT is address translation, not routing.
         | 
         | NAT makes it difficult for you to host services on your
         | network, forcing dependency on cloud services, and when ISPs do
         | it (CGNAT), it makes it just about impossible unless you want
         | to thread your traffic back through a third-party service. If
         | you want a good chance of keeping some semblance of an Internet
         | around that isn't dominated by huge centralized services, the
         | cargo cult of "NAT is security" needs to die hard.
        
           | tinus_hn wrote:
           | With NAT it is impossible to make a mistake that causes
           | machines with a private address to become reachable to the
           | internet. That is a reality that is not going anywhere, no
           | matter if you like it or not, no matter if you think it is
           | stupid or not.
        
             | unethical_ban wrote:
             | Every home router could be built with a default deny
             | inbound for traffic, with big flashing lights saying "do
             | not override this".
             | 
             | IPv6 has private addressing and a form of NAT as well, were
             | it to be the will of router mfg'ers and network admins. No
             | need to stay on a legacy protocol.
        
             | kazen44 wrote:
             | With Ipv6 this is even easier.
             | 
             | You simply do not host services you do want public on your
             | global unicast address but use a private/site local address
             | instead.
        
             | tenebrisalietum wrote:
             | UPnP?
             | 
             | Also STUN makes your private addresses reachable without
             | you making any mistake at all.
             | 
             | Your comment is a good example of the NAT cargo cult
             | mentality that is damaging to the Internet.
        
           | michaelt wrote:
           | Presumably what thesuitonym means is:
           | 
           | Imagine if I'm a medium-sized ISP, or a medium-sized software
           | company, or a medium-sized website.
           | 
           | There's a bunch of hassle involved in deploying IPv6. Who
           | knows what it'll do to my users' privacy? Or whether
           | everyone's firewall rules will keep working right? Or whether
           | it'll have some random impact on e-mail deliverability? Or
           | something else?
           | 
           | The main benefit of IPv6 is providing routable addresses for
           | home users, thus avoiding CGNAT.
           | 
           | But zealous firewalling and the rise of mobile devices mean
           | these days almost everything is sent over HTTPS to a cloud
           | server. I haven't had software ask me to open a port on my
           | router in a decade or more. Even games and video conferencing
           | software know they have to work out-of-the-box on networks
           | where the user can't adjust the NAT.
           | 
           | So who's going to benefit from all this hassle - the 0.1% of
           | users who are hosting websites from home?
        
             | AtlasBarfed wrote:
             | I've always posited that web services didn't become
             | widespread because of the church of REST, or even that the
             | HTTP protocol is that amazing.
             | 
             | It's because you could get through the firewall without a
             | four month review with the firewall team.
             | 
             | Well, and you could reuse web tools and software. Ok,
             | that's probably it, but the firewall convenience is
             | DEFINITELY a thing.
        
             | unethical_ban wrote:
             | If home router manufacturers would get their shit together,
             | IPv6 would not be hard to deploy. I get it, it's chicken
             | and egg, but nothing about IPv6 is inherently more
             | difficult than IPv4 other than the length of the address.
             | 
             | The reason IPv6 on a home network is still difficult is
             | because the routers everyone buys at Best Buy still blow at
             | supporting IPv6. Ubiquiti blows at supporting IPv6. It is
             | laziness and/or incompetence of device manufacturers,
             | primarily, holding us back. (and incompetence around IPv6
             | in general - I talked to a network guy at a large company
             | recently and they were deploying /58s. WHY?!)
             | 
             | The benefits of IPv6 may not be just for you - it's for the
             | planet, it's for the developing nations, it's for the
             | future where IPv4 _does not cut it_. It 's bigger than your
             | home network.
        
               | wankle wrote:
               | IPv4 cuts it everywhere. IPv6 does not do anything to
               | save the planet. IPv6 does have privacy concerns stated
               | by many on this page. IPv6 could be shut down tomorrow
               | and the Internet would continue working well.
        
             | xjay wrote:
             | The sad part to me is that the original IP header included
             | variable-length addresses up to 128 bits, using two 4-bit
             | fields called Source Address Length (SAL), and Destination
             | Address Length (DAL). [1]
             | 
             | Early hardware implementations could have settled on
             | 32-bit, but 48-bit would make more sense to be in line with
             | EUI-48/MAC-48 (ethernet frame). The world could then
             | gradually upgrade hardware over the decade to handle a
             | larger address.
             | 
             | [1] https://www.rfc-editor.org/ien/ien28.pdf
        
             | davikr wrote:
             | To "avoid domination by huge centralized services", of
             | course. What if you want to run something like a website
             | from your own IP, but you can't because you're behind
             | CGNAT?
        
               | wankle wrote:
               | I use a public VPS and Wireguard. Costs $3.50 for the VPS
               | which has a static IP. I host on my laptop. I can take my
               | laptop anywhere in the world there's an Internet
               | connection and my email and web sites continue to work
               | right from the same VPS IP because my laptop connects to
               | the Wireguard server on my VPS when it comes up.
        
             | tenebrisalietum wrote:
             | Another reason is that NAT is making IPv4 live longer than
             | it should, making IPv4 addresses more expensive. Maybe you
             | don't want to host cloud services from your home, but if
             | IPv4 addresses start costing millions of dollars (I know
             | blocks of them can go for that much--if we're already there
             | do you want to go further?), that drives up the cost for
             | anyone using the Internet even if you are super okay with
             | CG-NAT (which you shouldn't be).
             | 
             | IPv6 will fix that.
        
             | [deleted]
        
         | mavhc wrote:
         | NAT and a Firewall are two different concepts.
         | 
         | What's wrong with a firewall that blocks everything by default,
         | yet all your devices have a public IP?
        
           | waych wrote:
           | Maybe you don't want to reveal your internal infrastructure
           | to the world? Seems like basic opsec.
        
             | RealStickman_ wrote:
             | There's no chance of anybody guessing your infrastructure
             | just by looking at your subnet. (Minimum is /64, which is
             | HUGE!)
        
               | waych wrote:
               | Every packet leaving an IPv6 network that isn't NATed has
               | an effective node ID in the packet. No need to guess just
               | look at the packets.
        
               | justeleblanc wrote:
               | Your machines could change their IPs for every second of
               | every day and you wouldn't come close to exhausting your
               | /64 subnet for the next billion years.
        
               | waych wrote:
               | The limit of changing addresses once every N seconds as N
               | approaches 0 is equal to offline.
               | 
               | With any usable N, a clever observer would still easily
               | work out what you were doing and still map out your
               | infrastructure.
        
               | ianburrell wrote:
               | Why would changing N seconds break network? It would
               | presumably keep active addresses until connections
               | finish. IPv6 requires supporting multiple addresses per
               | interface.
               | 
               | More reasonable is to use new address for each
               | connection. Then nobody can tell if 10 addresses and 10
               | connections are one device or ten.
        
               | waych wrote:
               | This looks like NAT pushed down to the endpoint itself.
               | 
               | You've saved the translation in the router, but now
               | routing lookups and ARP caches have grown by
               | TEMP_VALID_LIFETIME / TEMP_PREFERRED_LIFETIME.
               | 
               | What are valid values in the scenario you are proposing?
               | The defaults are 1 week / 1 day, so 7X. If you chose to
               | rotate each second, and say allowed addresses to only be
               | valid for say 20 minutes, this still appears to be a
               | ~1200X blowup in routing overheads.
        
               | kazen44 wrote:
               | > You've saved the translation in the router, but now
               | routing lookups and ARP caches have grown by
               | TEMP_VALID_LIFETIME / TEMP_PREFERRED_LIFETIME.
               | 
               | They have not?
               | 
               | The global routing table size for ipv6 at max is a /32
               | (if i remember correctly) every customer gets a /56
               | prefix to use in their network, so the routing table
               | entry would still be the same, no matter how many
               | addresses you use to cycle through in your /64.
               | 
               | ARP caches do not exist in IPv6, and Neighbour discovery
               | does not have the same "cache" mechanism as ARP does, it
               | uses an entirely different mechanism for neighbour
               | discovery. (which is also far more lightweight
               | considering it is using multicast, compared to the
               | broadcast of ARP).
        
               | justeleblanc wrote:
               | What kind of observer is 1. able to listen to the
               | entirety of your network's outside communications, 2.
               | interested at all in it, 3. harm you only on the
               | condition that they "map out" your internal
               | infrastructure? This isn't a novel, the goal is not to
               | solve intricate security non-problems.
        
               | waych wrote:
               | "The network is secure" is a common fallacy.
        
               | justeleblanc wrote:
               | "Those who don't know what to say quote adages" is a
               | common saying.
        
               | Spivak wrote:
               | Your ISP, "mapping your network" means being able to take
               | data that was previously an amalgam of a household and
               | reliably split it into the individual members and devices
               | for better targeting.
        
               | bityard wrote:
               | Most devices support privacy extensions (temporary v6
               | addresses) for this exact reason. https://www.rfc-
               | editor.org/rfc/rfc4941
        
               | jlokier wrote:
               | Those IPv6 privacy extensions still reveal when the same
               | node connects to a sequence of destinations within the
               | address change interval, though. E.g. observers can see a
               | single device connects to Facebook, OnlyFans, Pornhub and
               | PayPal in that order.
               | 
               | Behind a NAT, observers can only make that connection
               | (using only addresses) for the network as a whole,
               | instead of an individual device on the network. So the
               | privacy extensions are weaker than NAT
               | 
               | (If the IPv6 privacy extensions used a different address
               | for each connection, they would be more like NAT in this
               | regard.)
               | 
               | That said, other observable clues still allow connections
               | from a single device to be associated, NAT or not.
               | There's TCP OS fingerprinting for example, and the close
               | timing of related connections.
        
               | waych wrote:
               | This helps mitigate correlations over time but doesn't do
               | anything to mask the identity of the node within a given
               | refresh interval (default one day).
        
             | [deleted]
        
             | mavhc wrote:
             | The whole world? How would that happen?
        
               | waych wrote:
               | Not the whole world. Just the world is sufficient.
        
             | wjholden wrote:
             | For HTTP/HTTPS, proxy servers (forward and reverse) offer
             | an equivalent ability to hide addresses and a lot more
             | features for security and performance.
        
           | op00to wrote:
           | Someone might know your IP, and somehow that information is
           | delicious and irresistible to evil .. uh .. spammers?
        
           | r3trohack3r wrote:
           | > NAT and a Firewall are two different concepts.
           | 
           | They are, but in practice they are muddled together and I
           | suspect people are going to create subnets with IPv6 in the
           | name of security. In IPv4 NAT is used to make sure your
           | laptop isn't exposed to random script kiddies trying to scan
           | for vulnerable services behind your router. A fun exercise is
           | to plug a RaspberryPi up directly to a public facing IP
           | address and log every packet it receives. Then give those
           | scripts a few services to detect (HTTP server, SSH server,
           | etc.) and look at how the traffic shifts from scanning for
           | ports to scanning for vulnerabilities. Being connected
           | directly to the public internet is a real eye opening
           | experience.
           | 
           | I do believe future IPv6 networks will have gateway machines
           | and/or bastions that are connected to the public internet
           | with public IPv6 addresses. And then they'll have an interior
           | network that they use NAT for. Individual machines will not
           | be routable or discoverable without going through a
           | bastion/gateway that explicitly controls the flow of traffic
           | into a network. Not because this is the ideal way to
           | structure an IPv6 network, but because this pattern is going
           | to carry over from the IPv4 world and there is a lot of
           | momentum in tribal knowledge using NAT as a form of firewall.
        
             | Arnavion wrote:
             | >In IPv4 NAT is used to make sure your laptop isn't exposed
             | to random script kiddies trying to scan for vulnerable
             | services behind your router.
             | 
             | NAT does nothing for that. Those incoming connections are
             | dropped on the WAN interface before NAT would even be
             | involved. Which is why it works exactly the same way
             | regardless of whether the destination IP for that traffic
             | was IPv4 or IPv6.
        
         | Asooka wrote:
         | Also I'm not going to expect my ISP to actually give me more
         | than one address, so if I have multiple devices at home, I will
         | need to do NAT. Heck, back in the day they used to set TTL to 1
         | so the packets weren't routable at all without mangling them
         | via iptables. Maybe that will be harder now than 20 years ago
         | since everything connects online...
        
           | cassianoleal wrote:
           | ISPs are expected to delegate a /56 or /64 prefix to
           | customers. Some are even delegating /48s. Mine delegates a
           | /56.
           | 
           | That should be enough for all your devices to randomly rotate
           | IPs for a lifetime or a few without any NAT.
        
             | Arnavion wrote:
             | https://news.ycombinator.com/item?id=24999906
             | 
             | Shitty ISPs do exist, or at least they existed two years
             | ago.
        
               | cassianoleal wrote:
               | Sure they exist, but should you expect your ISP to be
               | shitty? Sounds like a terrible deal for you.
        
       | dmuth wrote:
       | If you want to test to see if you're successfully sending out
       | IPv6 traffic, I have an endpoint for that:
       | 
       | https://httpbin.dmuth.org/ip/v6
        
       | amrb wrote:
       | He also has a video for the topic
       | https://www.youtube.com/watch?v=e-oLBOL0rDE
        
       | olddustytrail wrote:
       | > Addresses are 128 bits long and written as 8 four-letter hex
       | blocks separated by colons (i.e.
       | fd69:beef:cafe:feed:face:6969:0420:0001)
       | 
       | I suspect you mean "e.g." rather than "i.e."
        
       | sp0ck wrote:
       | My experience with IPv6. I have option to enable full dual stack
       | with my ISP. After doing this I noticed that YT/FB/Google were
       | significantly faster, however my kids started to complaing that
       | some games began to have connectivity issues. Minecraft have
       | problems to start. On a number of sites load time was noticebly
       | longer. Switching off IPv6 as a experiment on one of kids PC
       | solved all issues. My conslusion is that it is not worth to
       | enable IPv6 and spend time to diagnose constant issues with
       | random pages and services.
        
         | mritun wrote:
         | If we're talking anecdotally, I am running dual stack IPv6 and
         | have had zero issues with Minecraft or any other game on my
         | network on Xbox, Switch, iOS and PC.
        
           | Gigachad wrote:
           | Minecraft does not support v6 but I wonder what caused the
           | issues. Maybe the presence of v6 support caused DNS to give a
           | v6 address and this caused problems? Seems unusual.
        
         | hot_gril wrote:
         | First thing I do setting up any network is disable ipv6. It's
         | caused issues at least once, and that's one time too many for
         | something that doesn't benefit me in any other way.
        
           | kitkat_new wrote:
           | For me, the first thing is actually enabling ipv6
        
         | dekhn wrote:
         | Agreed- I turned on ipV6 and even tried turning off ipv4. All I
         | found was a bunch of new, different problems to debug that were
         | inevitably because somebody else somewhere doesn't support
         | ipv6, or I would have to run some sort of bridge between the
         | two networks. Of course this is for home where I don't need a
         | gajillion publicly-routed IPs.
        
         | nikanj wrote:
         | I have never fixed network problems by turning IPv6 on, but I
         | have fixed them numerous times by turning it off.
        
         | justeleblanc wrote:
         | I don't think this anecdote proves anything.
        
           | hot_gril wrote:
           | It doesn't say a lot. What says more is how often you seek
           | home networking advice and one of the first troubleshooting
           | steps is to disable ipv6 (though restarting the router is
           | probably first).
        
       | speedgoose wrote:
       | Why should I spend the time and energy to deal with IPv6 when
       | disabling it fix many issues ? The listed advantages are not
       | worth the troubles in my experience.
        
         | anderiv wrote:
         | It's not so much that the advantages of IPv6 are all that
         | compelling. Rather, it's more that the mechanisms put in place
         | to deal with a nearly-exhausted IPv4 pool (NAT, and CGNAT in
         | particular, etc.) are not great, and any opportunity to negate
         | the need for them ought to be pursued.
        
           | speedgoose wrote:
           | But you still need these mechanisms for the time being. And
           | personally, I do like NAT. I'm not a fan of exposing my
           | internal networks to the internet. Having everything hidden
           | behind a single address is neat.
        
         | api wrote:
         | I've run dual stack at home and at work for years and have had
         | no issues. You might have issues if you have really old junk
         | that's just broken.
        
           | speedgoose wrote:
           | My current internet provider doesn't support IPv6 so I'm
           | good. I noticed that removing the AAAA records in the DNS
           | configurations of my domains magically fixed a lot of weird
           | network issues reported by the users.
        
           | mynameisvlad wrote:
           | Works for me, so clearly not an issue amirite?
        
         | screamingninja wrote:
         | Increased number of available IP addresses, improved security
         | features, simplified network management, reduced network
         | complexity, and support for new technologies. The adoption of
         | IPv6 will lead to cost savings, improved network performance,
         | and increased scalability. Scalability may not matter in the
         | typical home network, but in an enterprise environment, the
         | cost of up-keeping the network backbone is significant.
        
           | everdrive wrote:
           | >simplified network management
           | 
           | I keep hearing this, but it doesn't seem more simple to me.
           | My ISP won't reserve me a /48, so I can't control the
           | management ips of devices on my network. The solution is
           | apparently to set up dynamic dns, which I have no interest in
           | doing.
        
             | screamingninja wrote:
             | Just split that /64 into smaller /80 subnets. If I were
             | your ISP, I would be upset too.
             | 
             | The apparent issue here is that you're falling back to
             | what's familiar- static IP addressing. How about mDNS?
        
               | jlokier wrote:
               | You can't use a smaller subnet than /64 for devices that
               | use SLAAC for address allocation.
               | 
               | (Unless you're putting them behind an IPv6 NAT, so thry
               | can have their oen private /64).
        
           | speedgoose wrote:
           | But that's in a world where IPv4 doesn't exist. But it does,
           | so I see an increased number of available IP addresses that
           | many people can't access, so you must keep an IPv4 stack
           | which makes everything more complex and more expensive.
           | 
           | I understand the support of new technologies but IPv6 is 27
           | years old.
        
         | ip26 wrote:
         | The advantage mostly falls to the infrastructure. In theory it
         | performs better, but only marginally, which is quickly
         | overwhelmed by simple issues like inferior routes. As an end
         | user, frankly I stopped caring long ago.
        
         | ec109685 wrote:
         | Would have been great if the post quantified the advantages.
         | 
         | For networks (order of preference): IPv6 only > IPv4 Only >
         | Dual Stack.
        
       | [deleted]
        
       | redog wrote:
       | I think ipv6 could happen if subsidized for long enough.
       | 
       | Something like, I'll-sell-you-my-v4-blocks-at-a-later-date-
       | forfreeipv6-bandwidth-today-as-a-service ...
       | 
       | Re-Send them nostalgic AOL CDs as the advertising...
        
       | [deleted]
        
       | czbond wrote:
       | Great idea. Now a question for the group.
       | 
       | What are the non-network team business benefits to IPv6 over v4?
       | That is what drives adoption.
        
         | api wrote:
         | IPv4 is now stretched to the point that you often end up
         | requiring multiple layers of NAT, such as carrier-grade NAT
         | plus endpoint NAT. That reduces the reliability of pretty much
         | all protocols and makes any protocol doing peer to peer
         | communication really hard or even impossible to run. The latter
         | includes tons of games, video chat, peer to peer VPNs,
         | decentralized social networks, and so on.
         | 
         | These problems will only get worse from here on out, but
         | they're not as visible to people outside networking because
         | this degradation of quality of service is a slow creep. The
         | IPv4 Internet just gradually gets more and more limited in
         | capability and less reliable for anything beyond the most basic
         | use cases.
         | 
         | IPv4's address space is simply too small. There are already
         | almost twice as many people on Earth as there are possible IPv4
         | addresses, and that assumes perfectly efficient utilization of
         | IP addresses which is pretty much impossible. In reality there
         | are probably 8-10X as many humans as viable IPv4 addresses. If
         | every human being tends to have a computer and a phone that
         | means there's at least 20X more devices than IPs.
        
           | PeterisP wrote:
           | I get that there are people in the world with severe lack of
           | IPv4 addresses and this is a valid reason for _them_ to
           | switch to IPv6.
           | 
           | However, assuming that I and my organization have enough IPv4
           | addresses (without requiring any of the tricks of multiple
           | layers of NAT), is there a sufficient reason for us to
           | justify the effort/expense of changing what works?
        
           | cesarb wrote:
           | > If every human being tends to have a computer and a phone
           | that means there's at least 20X more devices than IPs.
           | 
           | You know, that used to be only "if every human being tends to
           | have a computer", since phones didn't have an IP address. Now
           | it's "a computer and a phone". A few years down the line,
           | you'll have "a computer and a phone and a watch", then "a
           | computer and a phone and a watch and a standalone VR
           | headset", and so on.
        
         | screamingninja wrote:
         | Increased number of available IP addresses, improved security
         | features, simplified network management, reduced network
         | complexity, and support for new technologies. IPv6 also
         | provides significant performance benefits for mobile networks,
         | IoT devices, and cloud services. The adoption of IPv6 will lead
         | to cost savings, improved network performance, and increased
         | scalability.
        
           | [deleted]
        
           | ilyt wrote:
           | .... secure ? Is that ChatGPT answer ?
        
             | ianburrell wrote:
             | IPv6 being more secure used to be feature back when IPsec
             | was cool. IPv6 has better integration with IPsec. But
             | everyone is using TLS and other more secure VPNs these
             | days.
        
             | screamingninja wrote:
             | Unless you're calling NAT "more secure", yes, I maintain
             | that IPv6 is more secure. It simplifies network security
             | operations and especially makes it easier to understand
             | your network when you start visualizing logs and data with
             | a real threat hunting platform. Try dealing with IPv4+IPv6
             | vs IPv6-only in one of those dashboards.
        
         | crest wrote:
         | Less operational complexity. VPN overlays for remote
         | management, realtime peer to peer video and audio streaming,
         | etc. just work reliably. You also get to build the address plan
         | to fit your (business) requirements instead of working around
         | which addressspace is available where.
        
         | [deleted]
        
         | vlan0 wrote:
         | OPEX and CAPEX costs are significantly reduced with native IPv6
         | vs large NAT deployments. Adding layers to stretch IPv4 =
         | complexity/gear. Gear/complexity = higher costs.
         | 
         | And if you're already moving away from perimeter defense, to
         | more identity based zero-trust, the move to IPv6 makes much
         | sense.
        
           | everdrive wrote:
           | People are doing "zero trust" about as well as they're doing
           | agile. The concept may be real, but businesses' implantations
           | are not.
        
           | ianburrell wrote:
           | It is unfortunate that businesses are behind in rolling out
           | IPv6. I get the impression that IPv6-only is more doable and
           | has more advantages for business. It is feasible to run NAT64
           | in business cause don't have to support as much old software
           | like games that people want to play. It helps with internal
           | addressing issues which get complicated in big companies with
           | acquisitions. Finally, it adds a security barrier between
           | IPv4 for external and IPv6 for internal.
           | 
           | But upgrading a working network is lots of trouble. Most
           | existing businesses have plenty of public IPv4 addresses and
           | don't have to conserve.
        
         | dilyevsky wrote:
         | The benefit for the business is their eng team isn't bogged
         | down by working around ipv4 network cruft on big networks. On
         | small ones it probably doesn't matter yeah
        
       | MagicMoonlight wrote:
       | We should just make an IPv5 which takes a current address:
       | 216.3.128.12 and makes it 0.0.0.0.216.3.128.12
       | 
       | So any address of the current length you just treat it as if it
       | has zeroes in front, otherwise you use the longer length which
       | allows for many more addresses. Problem solved.
        
         | aidenn0 wrote:
         | You're leaving out what happens if an ipv4 only host gets a
         | packet from an ipv5 host. It only knows how to respond to a
         | 4-byte address.
         | 
         | If you manage to solve that problem, you'll probably have
         | invented something a lot like NAT64, which TFA talks about.
        
         | throitallaway wrote:
         | IPv6 became a draft standard in 1998; good luck with
         | introducing "IPv5." Most operating systems/devices have IPv6
         | for a very long time now, we just haven't been forced away from
         | IPv4 yet. IPv4 addresses are getting to be increasingly
         | expensive (and CGNAT really sucks); eventually a market tipping
         | point will be reached.
        
       | cooljacob204 wrote:
       | I recently upgraded my lab and network to support IPV6. I wish I
       | had waited two weeks so I could have read this first.
        
       | [deleted]
        
       | daper wrote:
       | I've given a try to IPv6 in a company with few tens on servers in
       | a 2 DCs, an office + additional location, 3 ISPs in total. For me
       | the real challenge is not just different way to write an IP
       | address or doing NAT. The challenge is that IPv6 changes a lot of
       | unexpected things:
       | 
       | - Our ISPs support IPv6 but routing quality is way worse than
       | IPv4 including occasional inability to connect to some networks
       | or greater latency than IPv4. I had to create tickets with such
       | issues understood that most probably they just don't have IPv6
       | BGP sessions to all their upstream providers they connect.
       | 
       | - How the VPN (an employee / road warrior setup) should be
       | configured since from the routing perspective you don't need a
       | VPN to connect from your home to the office? Assuming both have
       | proper IPv6 connection and all devices in the office and your
       | laptop have a globally addressable IP address. Employee can have
       | IPv4 or dual stack at his home, where is dual stack in the
       | office. Very confusing. Looks like Fortigate also don't have an
       | idea and decided to not support such case.
       | 
       | - You have to be careful with site-to-site VPN since even your
       | internal services like database are now globally addressable. You
       | really need proper firewall rules / routing policies to not leak
       | unencrypted packets over internet.
       | 
       | - SLAAC is cool but doesn't provide DNS configuration. (there is
       | RFC8106 but is it supported by all OSes?). You need DHCPv6 for
       | that. You have to choose: use only DHCPv6 or SLAAC + DHCPv6 or
       | just relay on the vast that DNS will be proviedd by DHCP IPv4 in
       | a dual stack setup.
       | 
       | - The way of providing high availability gateway address in a
       | network is different. You need router advertisement where you can
       | provide priorities. That actually is much better than any other
       | VIP mechanisms (no issue with MAC table updates, etc.) but you
       | need to know that.
       | 
       | - OSPF works a bit differently. For example: there is no
       | authentication in router communication in OSPF itself, you are
       | supposed to use IPSec.
       | 
       | The list is longer unfortunately...
        
         | apearson wrote:
         | > SLAAC is cool but doesn't provide DNS configuration. (there
         | is RFC8106 but is it supported by all OSes?)
         | 
         | For the most part, yes it's supported by major OSes. (ND RDNSS)
         | https://en.wikipedia.org/wiki/Comparison_of_IPv6_support_in_...
        
         | joshspankit wrote:
         | > You have to be careful with site-to-site VPN since even your
         | internal services like database are now globally addressable.
         | 
         | I'd bet that this will be the source of some gnarly leaks in
         | future. If it does my bet would be it's going to follow the
         | "API keys on GH" trajectory.
        
       | ajross wrote:
       | > You should stop thinking of NAT as a security mechanism and
       | think of it as the emergency address exhaustion prevention that
       | it is.
       | 
       | I hate this attitude. This is isomporphic to saying "stop
       | thinking of system call interfaces as a security mechanism and
       | think of them as an address space sharing mechanism". It's not
       | _technically_ wrong, but it 's wrong in practice.
       | 
       | Even the most naive NAT can't misroute an inbound packet. If you
       | have an internal host and it doesn't talk to anything outside the
       | firewall, then no one else can reach it. They have no name for
       | it, the packets won't go. You get this even if you don't
       | understand how it works. You get this even if the _router_ has no
       | idea about the host.
       | 
       | Give everything a unique address and now the router needs to know
       | who is safe and who isn't. That's a decision point that requires
       | configuration by human beings, and human beings get stuff wrong.
       | 
       | No, NAT is your friend. Use NAT. Use it even if you're an IPv6
       | nut.
        
         | kazen44 wrote:
         | why would NAT not be any configuration compared to Firewall
         | rulesets?
         | 
         | heck, they even inventend protocols to do automatic NAT setup
         | (UPNP) because configuring NAT by hand confuses people a lot.
        
           | TacticalCoder wrote:
           | Not commenting on the whole IPv6 vs IPv4 debate but simply
           | answering your question...
           | 
           | There aren't enough IPv4 addresses, so any ISP using IPv4
           | addresses is going to give 99.999% of their customers exactly
           | _one_ IPv4 address. Not ten. Not two. One.
           | 
           | So NAT _has to work_. Grandma has nothing to configure
           | because either NAT works or grandma is calling her ISP to ask
           | why her tablet ain 't working.
           | 
           | So when the customer gets exactly _one_ IPv4 address, the ISP
           | is _forced_ to hand a router doing IPv4 NAT. They have no way
           | around it.
           | 
           | While if you take an ISP handing out hundreds of billions of
           | IPv6 addresses to each customer, well... They are not
           | _forced_ to hand a router which does proper firewalling.
           | 
           | It's not a question of whether it'd be easier for the ISP to
           | give a correctly configured IPv6 router firewall vs handing
           | an IPv4 correctly doing NAT.
           | 
           | It's that when they hand one IPv4 address, they don't have
           | the choice. NAT must work and there's no way around it.
        
           | ajross wrote:
           | I'm sorry, I don't follow. Our grandparents have working,
           | secure NAT setups that no human being needed to configure.
           | I've never once seen a "firewall ruleset" configured by a
           | non-geek.
        
             | justeleblanc wrote:
             | Really? I changed ISPs the other day. Got my new
             | modem/router. You know what I did in terms of firewalls?
             | Nothing. You know what I have? A firewall that blocks all
             | unknown incoming connections. Does it work? Yes. Did I even
             | have to do anything besides plug in the box? No.
        
               | dragoncrab wrote:
               | Happy you.
               | 
               | All the 3 ISPs I dealt with in Hungary in the last 10
               | years provided 0 firewall capability for IPv6 in their
               | integrated router/modem.
               | 
               | Once you start assigning the addresses, every compatible
               | IoT gadget you have is reachable from the public web.
               | 
               | In this state, IPv6 is a pure security stepback for
               | average residential users with 0 upside.
               | 
               | I can't take any comment seriously who is speaking of
               | configuring a stateful firewall in a residential
               | environment.
        
       | AtlasBarfed wrote:
       | "although software support is virtually a requirement these days"
       | 
       | Who's fault is this again?
       | 
       | -------------
       | 
       | "- IPv6 is absolutely ready for prime-time and has been for
       | awhile
       | 
       | BUT
       | 
       | "- About half of the internet sites I rely on support IPv6
       | natively, so there needs to be more pressure on site admins and
       | CDNs to support IPv6 natively"
       | 
       | That is a contradiction.
       | 
       | -----------
       | 
       | "There seems to be a lack of drive (judging by forum posts) to
       | enable IPv6 on internet services by admins, either because they
       | don't care to, or it's more work to manage a public IPv4 and
       | public IPv6 presence"
       | 
       | Again, who's fault is it that its so hard? What is the payoff for
       | the extra work?
       | 
       | -----------
       | 
       | - Networks should be designed IPv6-first instead of IPv4-first,
       | and this design approach largely solves most of the major issues
       | 
       | K thanx, but that's not the way virtually every company works.
       | Mayyyyybe a startup? This is unrealistic.
       | 
       | -----------
       | 
       | "Other operating systems are bit of hit or miss"
       | 
       | so... IPV6 is NOT NOT NOT ready for prime time, is that what you
       | are saying?
       | 
       | -----------
       | 
       | What dream world are the ipv6 people living in?
       | 
       | I love this. Who should be implementing ipv6 stacks in OS's?
       | Probably ipv6 people, but ... where are they again? The amount of
       | blame is crazy.
       | 
       | A protocol switchover of this magnitude is about outreach and
       | assistance. The ipv6 crowd has NEVER displayed that, just
       | arrogance, dismissal, and waited for things to get "so bad" in
       | ipv4 that it transferred.
       | 
       | Which is why ipv6 people HATE HATE HATE NAT. It has delayed their
       | grand moment by decades.
       | 
       | ...
       | 
       | In an ideal world, the ip++ protocol would have been easier, not
       | harder. BLog posts wouldn't be victim blaming, throwing around
       | NAT64, 464XLAT, DNS64
       | 
       | DNS64 kills me. WHy is there a totally different service for
       | ipv6? Isn't DNS just a key-value store? People put all types of
       | crap into DNS, including, I believe, ipv6 addresses.
       | 
       | Why isn't there a DNS record type that basically lists both an
       | ipv4 and ipv6 for a name, along with negotiation information?
       | Might that make transition a lot easier? Maybe it does, but it
       | isn't in this article.
       | 
       | Just ... all the same problematic attitudes, no progress on
       | issues, my way or highway, and denial.
        
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       (page generated 2023-03-06 23:00 UTC)