[HN Gopher] Reasons for servers to support IPv6
       ___________________________________________________________________
        
       Reasons for servers to support IPv6
        
       Author : pingiun
       Score  : 233 points
       Date   : 2022-01-29 14:15 UTC (8 hours ago)
        
 (HTM) web link (jvns.ca)
 (TXT) w3m dump (jvns.ca)
        
       | dopa42365 wrote:
       | My ISPs v4 is down sometimes (Vodafone in Germany), while v6
       | continues working just fine. Severe loss of legacy internet
       | services in those situations (no twitter, reddit, pornhub,
       | battle.net, twitch...)
        
         | she46BiOmUerPVj wrote:
         | I have the same with Comcast in south east US. Browsing the
         | internet IPv6 only is depressing unless you only use Google :/
        
         | gtirloni wrote:
         | Here it's the opposite. My ISP's IPv6 network is so bad I've
         | had to request them to disable IPv6 at my router.
        
       | woile wrote:
       | What is a good resource to learn about ipv6? some course or book?
        
         | zamadatix wrote:
         | I've read many an IPv6 book and led many an IPv6 projects/in
         | person training classes and, as lame as it may sound, the
         | Wikipedia page is an amazing resource to get the background
         | needed to understand home and homelab setups.
         | https://en.wikipedia.org/wiki/IPv6
         | 
         | I'd recommend diving into the more detailed articles it links
         | on SLAAC (alternative to DHCP, most common way to dynamically
         | assign addresses) and NDP (replaced ARP) for a full
         | understanding. If you want to go all in for v6 only setups with
         | access to the v4 internet NAT64 is worth reading as well.
         | 
         | Obviously it doesn't cover how to configure/implement for your
         | specific scenario but it gives a solid background that lets you
         | better understand what guides for doing it with Linux or
         | prosumer hardware or typical consumer hardware are actually
         | talking about.
        
       | curious_cat_163 wrote:
       | I tend to think that a lot of issues on the global internet are
       | not technical problems. They tend to be economics problems.
       | 
       | v6 is a mechanism like container ships. It will dominate when the
       | incentives and disincentives make sense for the participants.
        
       | spockz wrote:
       | What is the best way to get ipv6 if your ISP doesn't support it?
       | I tried getting HurricaneElectric to work for tunnelling on my
       | Ubiquity USG3 but couldn't make it to work.
       | 
       | What would be the best way to get ipv6?
        
         | justincormack wrote:
         | Tunneling with HE is usually the easiest way...
        
           | xfer wrote:
           | Not if they already block icmp traffic.
        
           | withinboredom wrote:
           | Agree and would like to add that you may want to disable ipv6
           | tunneling for streaming services. (Google it) because they
           | consider it a "vpn" thus you must be a copyright thief. (Yet
           | any other "real" vpn will stream just fine lol)
        
       | hippyup wrote:
       | I'd love to read an honest post from somebody from Twitter (or
       | GitHub or...) on why they don't support IPv6. Not a shaming
       | thing, it's something I don't quite get. Like I get why an old
       | school bank wouldn't: their infrastructure predates IPv6 and it's
       | a project that has to be financially justified and I can
       | understand how that can be hard. But presumably something like
       | Twitter had an experienced networking team, who surely know all
       | the advantages here and want to somewhat future-proof, build up
       | their infrastructure and they decided not to support IPv6 and I
       | would love to understand the reasoning. Is the extra cost really
       | that high?
        
         | tw611345 wrote:
         | Why would they?
         | 
         | - IPv6 is basically an abandoned standard. I wouldn't expect
         | them to support gopher either.
         | 
         | - Residential ISP support for ipv6 is spotty, and anyone who
         | does offer ipv6 offers ipv4 as well.
         | 
         | - When it is supported, ipv6 tends to be substantially slower
         | than ipv4 in practice.
         | 
         | - The addresses are a pain to look at and work with.
         | 
         | - You now have twice as many things to fail.
        
           | throwaway2048 wrote:
           | ipv6 is hardly an abandoned standard, 35% of google users
           | access google over ipv6, and it continues to grow every year.
           | 
           | https://www.google.com/intl/en/ipv6/statistics.html
           | 
           | IPv6 is also usually faster than ipv4 these days, because the
           | overhead of fragmented ipv4 routing is large. In the past it
           | was slower because of lack of understanding/support for it
           | from larger ISPs, and consequently poor routes, or really
           | suboptimal tunneling setups.
        
         | yjftsjthsd-h wrote:
         | I have no special insight, but it's probably something like
         | "we're working on it, but there are lots of legacy things that
         | expect v4 (including non-obvious like anti-abuse systems) and
         | since all our users have _some_ sort of v4 connectivity it 's
         | not urgent".
        
         | boris wrote:
         | I am guessing the reasoning goes like this: if we only support
         | IPv4, then it's on all these ISPs with IPv6-to-IPv4 CGNAT to
         | make sure their stuff works properly (and chances are they will
         | notice if it doesn't). But if we support IPv6, it will be on us
         | to make sure people behind those ISPs can still reach us
         | (because hardly anyone goes via this IPv6 route and if it
         | doesn't work it's likely nobody at the ISP will notice).
        
           | Symbiote wrote:
           | 35% (by number of users) isn't "hardly any".
           | 
           | It should be a greater proportion by bandwidth, cause several
           | huge sites support IPv6 (Netflix, Youtube, Facebook etc), but
           | I can't find figures.
        
             | [deleted]
        
       | teddyh wrote:
       | _The Case for IPv6_ (1999):
       | 
       | https://datatracker.ietf.org/doc/html/draft-iab-case-for-ipv...
       | 
       | (EDIT: Updated to non-archive link provided by cesarb)
        
         | cesarb wrote:
         | Non-archive link: https://datatracker.ietf.org/doc/html/draft-
         | iab-case-for-ipv...
        
           | teddyh wrote:
           | Thank you! (I have edited my link to use yours.) The link I
           | originally had went bad due to the renaming from "draft-ietf-
           | iab-case" to "draft-iab-case", so I assumed that the document
           | had somehow vanished, and changed to an archive.org link.
           | Thank you for pointing me to the correct link again!
        
       | ClumsyPilot wrote:
       | IPv6 is a 'tragedy of the commons' issue just like recycling: you
       | get no benefits to you individually from addressing the issue.
       | 
       | However the day the issue is solved, and ee can forget IPv4, a
       | myriad issues dissapear - routing, port forwarding, P2P software
       | for torrents and calls, multiplayer games, etc.
        
         | drran wrote:
         | IPv6 has a political issue. Support for IPv4 addresses
         | (::0.0.0.0) was removed, because IPv6 users were able to
         | connect to IPv4 hosts directly, bypassing IPv4 NAT's and
         | firewalls.
        
           | drran wrote:
        
           | yjftsjthsd-h wrote:
           | > Support for IPv4 addresses (::0.0.0.0) was removed, because
           | IPv6 users were able to connect to IPv4 hosts directly,
           | bypassing IPv4 NAT's and firewalls.
           | 
           | How's that work? It can't be sending actual v4 traffic or
           | it'd work like normal v4.
        
             | wyufro wrote:
             | It was using IPv6 in IP, just like 6to4, protocol 41.
             | 
             | I haven't heard it called a political issue before though.
             | It just had problems, like being blocked in firewalls and
             | security problems where the encapsulated packet wasn't
             | checked properly, etc.
        
               | drran wrote:
               | I'm not a native speaker, so I apologize.
               | 
               | > The "IPv4-Compatible IPv6 address" is now deprecated
               | because the current IPv6 transition mechanisms no longer
               | use these addresses.
               | 
               | <<We forbid you to go right because we are going left.>>
               | It doesn't look like a technical issue. How I should call
               | it?
        
               | wyufro wrote:
               | Right. Neither am I, so take this with a grain of salt.
               | But I'd use "committee decision" in this case.
        
             | drran wrote:
             | IPv6 is large enough to represent the whole IPv4 range.
             | Multiple times. Initially (at the very beginning) it was
             | possible to connect to IPv4 address using IPv6 socket. They
             | were called <<IPv4-Compatible IPv6 Address>>[0]. For
             | example, I can ping both ipv4 and ipv6 addresses using
             | ping:                 $ ping 127.0.0.1       PING 127.0.0.1
             | (127.0.0.1) 56(84) bytes of data.       64 bytes from
             | 127.0.0.1: icmp_seq=1 ttl=64 time=0.048 ms            $
             | ping ::1       PING ::1(::1) 56 data bytes       64 bytes
             | from ::1: icmp_seq=1 ttl=64 time=0.044 ms
             | 
             | However, this feature allowed to bypass NAT and connect to
             | IPv4 hosts directly via IPv6, so it deprecated. (I skipped
             | names to avoid scapegoating).                 $ ping6 ::1
             | PING ::1(::1) 56 data bytes       64 bytes from ::1:
             | icmp_seq=1 ttl=64 time=0.043 ms            $ ping6
             | 127.0.0.1       ping6: 127.0.0.1: Address family for
             | hostname not supported
             | 
             | It's not a technical issue, see above: it's possible to
             | serve both protocols at the same time. It worked for a
             | brief period. It's purely political decision: backward
             | support for IPv4 in IPv6 was disabled because some people
             | are thinking that such behavior is dangerous.
             | 
             | [0]: https://datatracker.ietf.org/doc/html/rfc4291#section-
             | 2.5.5....
        
         | ATsch wrote:
         | As often when people reference the metaphor of the tragedy of
         | the commons, which had no historical basis in reality (quite
         | the opposite), there's more going on here.
         | 
         | IPv4 addresses are a significant competitive moat for incumbent
         | businesses. Existing companies have no interest in making IP
         | addresses a non-scarce resource that aids competitors or
         | alternatives (on-prem hosting, p2p, local ISPs, etc).
         | 
         | The only reason things have begun changing recently is
         | government mandates and that the moat has gotten so big that
         | they've started falling into it themselves.
        
           | jaystraw wrote:
           | Tangent, but as someone who often finds the tragedy of the
           | commons as the simplest explanation to many things, I'm
           | interested in hearing your take on it
        
         | spookthesunset wrote:
         | > port forwarding
         | 
         | Well, you are gonna have to replace port forwarding with
         | firewall rules instead. At least for me, I really don't excited
         | about my parents or in-laws internal networks being wide open
         | to the internet. Thus their entire subnet would need to sit
         | behind a "default deny" firewall. And if they need to expose
         | some service to the internet, they'd need to punch a hole in
         | the firewall--which is exactly the same dance you'd have to
         | play with port forwarding.
         | 
         | The only thing IPv6 brings to the table for consumers is each
         | device gets a globally routable address. But that doesn't mean
         | each device can or should be be reachable from outside the
         | router. One way or another client software will not get away
         | from having to open ports on the router.
        
           | DarylZero wrote:
           | > And if they need to expose some service to the internet,
           | they'd need to punch a hole in the firewall--which is exactly
           | the same dance you'd have to play with port forwarding.
           | 
           | The difference being, with IPv4 only one machine in the house
           | can have a port open. You don't just open a port, you choose
           | _which_ single machine gets the port. Sometimes you can't
           | open a port on a machine because the port's already taken.
           | 
           | With IPv6 any/every machine can have the same port open at
           | the same time.
           | 
           | One of these scenarios is obviously just broken.
        
           | franga2000 wrote:
           | The difference is that with a firewall, you open the port and
           | that's that. With port forwarding, you get whatever port
           | happens to be available. If done manually, you have to tell
           | the other sode which port to use. If done automatically (like
           | upnp), you need to do that every time your port changes.
        
             | tsimionescu wrote:
             | There is no difference of opening a port in a firewall or a
             | NAT (well, as long as there is a single machine that wants
             | to listen on that port, at least).
             | 
             | And some kind of UPnP will still be required even if your
             | internal network were using ISP-assigned IPv6 addresses for
             | protocols that want to open multiple connections, like VoIP
             | conferencing, bit torrent etc.
             | 
             | Of course, if you have an internal network where you
             | actually communicate between your various machines, you
             | won't want to use ISP-assigned publicly routable IPs, since
             | those can change at any time, so you'll also need some kind
             | of network address translation at the edge.
        
               | franga2000 wrote:
               | > well, as long as there is a single machine that wants
               | to listen on that port, at least
               | 
               | Well yes, most networks have more than one machine and
               | multiple users might want to run the same service.
               | 
               | > you'll also need some kind of network address
               | translation at the edge.
               | 
               | Not at all, each machine gets two addresses - one
               | routable from the ISP and one non-routable from the
               | router. Internal services simply use the non-routable
               | ones.
        
         | cm2187 wrote:
         | There is one individual incentive though: the increasing cost
         | of v4 addresses.
        
           | netr0ute wrote:
           | Why do IPv4 addresses even cost money? They're no better than
           | NFTs and don't even have a "token" of their own.
        
             | Nextgrid wrote:
             | They're a scarce commodity, and unlike NFTs, have a real
             | use-case.
             | 
             | Until everyone moves to IPv6, if you want people to be able
             | to reach your service, you need an IPv4 address. If you're
             | an ISP or cloud provider, you need those so your customers
             | can still communicate with v4-only peers.
        
             | fishtacos wrote:
             | Not sure how they're even comparable on any aspect.
             | 
             | IPV4 addresses are scarce due to lack of foresight and
             | useful.
             | 
             | NFTs are scarce by design and useless.
        
               | netr0ute wrote:
               | > NFTs are scarce by design and useless.
               | 
               | That's rich
        
               | ignoramous wrote:
               | > _NFTs are scarce by design and useless._
               | 
               | So, I know of one real-world usecase that's not useless:
               | Some startups have begun legally selling properties
               | (homes, ranches, plots) via NFTs.
        
               | fishtacos wrote:
               | What does the use of NFTs change in the transaction?
        
               | panqueque wrote:
        
               | simonw wrote:
               | Oh fun, which startups are those?
               | 
               | Real estate on the blockchain is my favourite bad
               | blockchain idea because if someone loses access to their
               | wallet they presumably lose the ability to ever sell
               | their house.
        
               | ignoramous wrote:
               | > _Oh fun, which startups are those?_
               | 
               | Some are covered in this article:
               | https://archive.is/k3w7F
               | 
               | > _...if someone loses access to their wallet they
               | presumably lose the ability to ever sell their house._
               | 
               | It is software at the end of the day and seems like there
               | is already a solution for it:
               | https://en.bitcoin.it/wiki/Multi-signature
        
               | Dylan16807 wrote:
               | So two escrow companies and I each have 2-of-3 keys.
               | 
               | At this point what is the blockchain providing that
               | normal title records don't?
        
               | simonw wrote:
               | The startups in that article don't seem to be selling
               | entire properties on the blockchain though - it looks
               | like they're doing things like buying a property and then
               | selling fractional interest in that property to different
               | investors as tokens.
               | 
               | I'll believe that multi-sig wallets solve this when I
               | hear frequent stories about regular human beings (not
               | highly sophisticated tech insiders) who both understand
               | them and use them successfully.
        
               | mrkurt wrote:
               | You just gotta etch the block into the foundation. Then
               | it's physically part of the house. Maybe make a
               | radioactive label and bury it on the property. That way
               | people now the property they're standing is on actual
               | property.
        
               | tialaramex wrote:
               | Nah, it just becomes one of those impediments to sale
               | that you wave aside during purchase and earns lawyers a
               | few bucks.
               | 
               | There are a few of these in England, Chancel Repair
               | Liability is the most famous. In _theory_ you could be
               | forced to pay for repairs to a nearby church you never
               | visit and have no interest in, on account of land you own
               | was historically liable for such repairs and this was
               | never cancelled. A real person, this century, had to pay
               | about PS350 000 as a result, so that 's not
               | inconsequential (although the circumstances were pretty
               | unusual). But that's scary enough that a real estate
               | lawyer might argue they're not _sure_ the property you
               | want to buy is unaffected, you should take out Insurance
               | against the liability, conveniently sold by another
               | lawyer.
               | 
               | The government tried to "fix" this, but the problem with
               | lawyers is, obviously no fix will be good enough to
               | prevent lawyers saying what if the fix didn't work, so
               | chances are you get persuaded to buy insurance _even
               | though the liability probably no longer exists_ because
               | hey, if I 'm wrong I'm not going to pay PS350 000 so...
               | 
               | Fifty years from now, if the fact there's "an NFT on the
               | blockchain" for a property you want to buy is even
               | something anybody knows about, your lawyer will know, and
               | they'll tell you that another lawyer offers $1000
               | insurance, buy that and if "the blockchain" ever tries to
               | sue you and take the property back they'll have your
               | back...
        
             | codechad wrote:
        
             | kazen44 wrote:
             | what?
             | 
             | ipv4 addresses are unique in the default free zone. they
             | cost money because without having a prefix that is unique,
             | you cannot route across the internet.
        
             | patmorgan23 wrote:
             | IPv4 addresses have utility. You still need one in order to
             | participate in the largest communication network in the
             | history of the earth. And theirs a limited number of them.
             | Demand + Scarcity = non-zero price.
             | 
             | What utility do NFTs provide other than
             | entertainment/status?
        
               | netr0ute wrote:
               | Who enforces the price? I can just advertise any address
               | I want with BGP.
        
               | baq wrote:
               | and be promptly kicked off the internet by your isp... or
               | somebody elses.
        
               | netr0ute wrote:
               | Unless you own routers that other ISPs almost depend on,
               | then you can say "take it or leave it"
        
               | iso1631 wrote:
               | So lets say Centurylink decide to start advertising
               | blocks they don't own, people like Cogent and Tata drop
               | their links, people with multiple ISPs drop their links
               | (shifting traffic to other tier 1 ISPs), and those with
               | centurylink only change their ISP because they can no
               | longer get to facebook.
        
               | netr0ute wrote:
               | That would work if most people had multiple ISPs, but
               | most don't actually. Thus, you have some bargaining
               | power, especially if you have some network advantage or
               | feature nobody else has.
        
               | midasuni wrote:
               | If your local ISP advertises the wrong prefixes they get
               | cut off by transit and peers and their customers complain
               | they can't get to any sites.
        
               | netr0ute wrote:
               | Then that ISP can take it or leave it if their customers
               | are complaining.
        
           | baq wrote:
           | another reason why folks holding large chunks of ipv4 address
           | space don't want ipv6 - they don't want to see their asset
           | drop in value.
        
       | js2 wrote:
       | > When I try to ping an IPv6 address (like example.com's IP
       | 2606:2800:220:1:248:1893:25c8:1946 for example) I get the error
       | ping: connect: Network is unreachable. Why? (answer: it's because
       | my ISP doesn't support IPv6 so my computer doesn't have a public
       | IPv6 address)                   $ ssh freenas.local
       | freenas$ ping6 2606:2800:220:1:248:1893:25c8:1946         ping6:
       | UDP connect: No route to host
       | 
       | Crap I should fix that. Login to web-interface, click the "IPv6
       | Autoconfigure" checkbox, click test, click save.
       | freenas$ ping6 2606:2800:220:1:248:1893:25c8:1946
       | PING6(56=40+8+8 bytes) 2600:1700:3d40:6300:6a05:caff:fe58:a370
       | --> 2606:2800:220:1:248:1893:25c8:1946         16 bytes from
       | 2606:2800:220:1:248:1893:25c8:1946, icmp_seq=0 hlim=54
       | time=11.408 ms
       | 
       | Wow, IPv6 _is_ easy! :-)
       | 
       | (AT&T is my ISP and it took a bit of screwing around over a
       | weekend with my router a couple years ago to get IPv6 working
       | properly on my home network. But it's been painless ever since.)
        
         | zamadatix wrote:
         | If you like tinkering and you've got the AT&T fiber service and
         | don't use the voice/TV U-Verse stuff) you can get significantly
         | better IPv4 and IPv6 performance not using their gateway (even
         | if it's just in bridge mode with every service disabled). It's
         | not officially supported and they actually 802.1x auth the
         | modem but there are convenient scripts out there to proxy the
         | auth packets allowing you to use your own router directly.
         | Particularly helpful for maxing out their gig service or for
         | drastically improving jitter at any service speed.
        
           | js2 wrote:
           | Yup, this is me: https://github.com/jaysoffian/eap_proxy
           | 
           | AT&T has transitioned to issuing a combined ONT/Router, where
           | this will no longer be possible, but apparently the newer
           | gear doesn't have any of the performance issues of the Pace
           | 5268AC.
           | 
           | BTW, I was annoyed that AT&T installed the ONT on the
           | southern wall of my home where it was baking in full sun
           | everyday, so I relocated it myself into my network closet.
           | You can just unplug the ONT and extend the existing fiber
           | with an optical coupler and an SC-APC to SC-APC single-mode
           | patch cable.
        
             | zamadatix wrote:
             | Lol HN is amazing, this was actually the first one I got to
             | work a few years back! Kudos for the tool - it worked
             | wonders.
             | 
             | Have you heard what gear they are using for the new >1G
             | deploys? I haven't kept as up to date with ONT/GPON gear
             | the last couple of years but I'm curious what they have
             | that does 5 gigabit NAT.
        
         | iso1631 wrote:
         | So despite spending thousands of dollars on time getting your
         | router to work, ipv6 didn't work, but you didn't notice for 2
         | years?
        
           | js2 wrote:
           | No, it's been working fine on all my Apple devices. I just
           | hadn't configured the interface on my freenas server.
           | 
           | And my free time isn't billable.
        
       | stevefan1999 wrote:
       | in case you didn't know you can either try Tunnel Broker project
       | or 6to4 [1] relay, both proudly presented by Hurricane Electric
       | 
       | [1]: https://en.wikipedia.org/wiki/6to4?wprov=sfla1
        
       | nunez wrote:
       | IPv6 is cool in theory and the idea of literally everything
       | having its own directly-reachable IP address is extremely
       | compelling, but I never use it because so many services STILL
       | don't support it or don't support it correctly. (As Julia pointed
       | out, some HUGE websites don't have quad-A records, so good luck
       | dealing with NXDOMAIN for like everything.)
       | 
       | Shoot, Kubernetes _just_ got support for IPv6 in 1.23 (it was in
       | beta since 1.20). I know that 6to4 exists and many kernels can do
       | it out of the box, but that comes with problems, as Julia
       | rightfully pointed out here, and at that point, you might as well
       | just NAT over IPv4.
        
         | she46BiOmUerPVj wrote:
         | You mean you explicitly disable it? Or you never use sites like
         | Google or Netflix? Why would you get NXDOMAIN for anything with
         | IPv6 enabled? No ISP would only offer IPv6 without IPv4 as
         | well.
        
       | baggy_trough wrote:
       | Still waiting for Google Cloud Platform to support IPv6 to the
       | box...
        
         | uji wrote:
         | It is already supported.
         | https://cloud.google.com/compute/docs/ip-addresses/configure...
        
           | baggy_trough wrote:
           | Still waiting in my region (they only support asia-east1,
           | asia-south1, europe-west2, us-west2). Hopefully some year.
        
       | l0b0 wrote:
       | By now I'm semi-convinced ISPs are deliberately holding back IPv6
       | in order to make a buck selling static IPs. They charge a good
       | chunk of money per month for an IPv4 address (at least in
       | Switzerland, the UK, and New Zealand), which is basically just
       | rent extraction from artificial scarcity. And it's pretty obvious
       | that once they transition to IPv6 there is no good reason not to
       | give every single customer enough static IPs for a lifetime of
       | devices.
        
       | yjftsjthsd-h wrote:
       | A few of these reasons boil down to "it's faster to not NAT".
       | That makes some intuitive sense, but does anyone know of any
       | studies/tests so we can get numbers? Are we talking higher time
       | to first connect? Slight increase in hops/latency on every
       | packet?
        
       | cm2187 wrote:
       | Joining the other thread about ipmi/iLO interface being exposed
       | to the WAN: make your server non discoverable by the different
       | services that scan the entire internet address space. It is
       | security by obscurity and you must have other layers of security
       | but it's not an insignificant layer.
        
       | oofabz wrote:
       | >reason: to avoid NAT issues with home servers
       | 
       | Home servers are not quite as easy as the article makes it sound.
       | Home routers block incoming IPv6 packets, the same as they do for
       | IPv4. To make a home server accessible, you need to explicitly
       | allow that incoming IPv6 traffic in your router's firewall. This
       | is analogous to adding a port forward rule in IPv4 NAT. The only
       | benefit IPv6 has here is you can use the same port (e.g. SSH) for
       | multiple home servers.
        
       | kim0 wrote:
       | Does anyone have an explanation about "reason: to own your IP
       | addresses" .. does that actually work?
        
         | rmoriz wrote:
         | As a LIR you can request network address space tied to your
         | organization. To my knowledge there are almost no cloud hosting
         | providers that support "bring your own IP space". Vultr.com
         | seems to be the sole exception.
        
       | ugjka wrote:
       | > A few people mentioned that it's much easier to use IPv6 with
       | home servers - instead of having to do port forwarding through
       | your router, you can just give every server a unique IPv6 address
       | and then access it directly.
       | 
       | My ISP firewalls IPV6 addresses on their end, so no ssh to my
       | IPV6 Machines from the outside, not even ping works. I don't know
       | why they do this
        
         | dspillett wrote:
         | A lot of residential ISPs block certain incoming traffic (any
         | that doesn't seem to be part of a stream originated at the user
         | side in some cases) by default because many home users who have
         | something open did not open it intentionally themselves so it
         | could be an insured attack vector.
        
         | kijin wrote:
         | Unless you have a gazillion servers at home, port forwarding
         | through a router is fairly simple and has the additional
         | benefit of a rudimentary firewall. So there isn't a clearly
         | visible benefit for most people. Most people can't even tell
         | whether they're behind carrier-grade NAT. It makes no tangible
         | difference in their lives.
         | 
         | Techies like you and I can appreciate the technical arguments,
         | but if we want to convince anybody else who can actually make
         | decisions for large numbers of ordinary people, we're going to
         | need better arguments.
        
           | zekica wrote:
           | But this is only because everything mainstream that is P2P
           | uses some kind of a centralized relay server. P2P would be
           | much much cheaper for everyone if everyone used IPv6, so it
           | makes a difference.
        
             | spookthesunset wrote:
             | > P2P would be much much cheaper for everyone if everyone
             | used IPv6, so it makes a difference.
             | 
             | I dunno how true that is gonna be. P2P clients will still
             | have to traverse a firewall that may do deep packet
             | inspection. A lot of the problems faced by P2P will still
             | exist even in a pure IPv6 world.
        
             | kijin wrote:
             | Tell that to management. As soon as they hear "P2P" they
             | will decide to perpetuate the status quo that makes P2P
             | hard, because P2P is evil and illegal in their books.
             | 
             | And we sit here wondering why the powers that be are not
             | interested in faster IPv6 adoption. Few if any of the
             | reasons we exchange on HN have any bearing outside of this
             | bubble. A typical business in 2022 still has no incentive
             | to embrace IPv6, facilitate P2P, or make the internet more
             | decentralized.
        
               | tsimionescu wrote:
               | How would you facilitate P2P in an IPv6 world? Do you
               | stop using a firewall and just let anyone open
               | connections to your machine on any port from the
               | internet? If not, how do you allow connections from peers
               | but not random botnets?
               | 
               | Not to mention, would you really use IPv6 addresses that
               | your ISP assigns for your internal network as a business?
               | Do you really want to re-IP everything if you find a way
               | to switch ISPs?
        
             | tsimionescu wrote:
             | > P2P would be much much cheaper for everyone if everyone
             | used IPv6, so it makes a difference.
             | 
             | How would P2P work any different in an IPv6 world? You
             | still need to open a port for each incoming connection,
             | which still isn't secure unless the target machine is
             | explicitly requesting this.
        
           | nrabulinski wrote:
           | I don't get the "firewall" argument. You can use the firewall
           | the same way with v6 as you do with v4, only allow incoming
           | traffic on specific ports, just minus the NAT which makes
           | everything simpler and better for everyone
        
         | davidmurdoch wrote:
         | They likely still sell static ipv4 addresses, which made sense
         | back in the day, but ipv6 doesn't work with the existing
         | monetization model. I had the same sort of issue and when I
         | called about it they tried to upsell me to a business account.
        
       | johnklos wrote:
       | It's good to wonder publicly and have a discussion!
       | 
       | I set up IPv6 on all my servers in 2001 and thought we'd all be
       | on IPv6 in just a couple of years :P
       | 
       | What's interesting is how much resistance there is to adding IPv6
       | which comes from entrenched IT. People who never learned (much)
       | about IPv6 seem to be afraid of it and often respond with some
       | variant or another of "don't fix it if it ain't broke", or "it's
       | extra work for no return", or "we'll have to pay licensing to add
       | IPv6 because we bought crap routers, so let's not", et cetera.
       | 
       | My favorite is, "we have no record of people trying to use IPv6"
       | - yes, that's real :D
       | 
       | It just shows their ignorance. Adding IPv6 has myriad advantages
       | - no need for NAT, proxies or port forwards to share addresses,
       | no need to renumber networks if allocations or upstream change,
       | redundancy, valid security-through-obscurity (imagine port
       | scanning a /64 looking for open ssh ports)...
       | 
       | What's really interesting is how many of these "we fear change"
       | IT people don't realize they're already using IPv6 on their
       | phones every day, with a majority of the sites they visit.
        
         | red_trumpet wrote:
         | > What's really interesting is how many of these "we fear
         | change" IT people don't realize they're already using IPv6 on
         | their phones every day, with a majority of the sites they
         | visit.
         | 
         | Not true on my german mobile carrier O2. They only provide IPv4
         | behind a CGNAT.
        
         | yjftsjthsd-h wrote:
         | > What's interesting is how much resistance there is to adding
         | IPv6 which comes from entrenched IT. People who never learned
         | (much) about IPv6 seem to be afraid of it
         | 
         | Right, you're only suggesting that they change out a
         | fundamental part of the network for no benefit that they can
         | see; why would they possibly object except out of fear and
         | ignorance? After all, their fears are totally unfounded; most,
         | probably all, of the random breakage and slowdowns that
         | happened last time they tried to enable v6 have been fixed now.
         | 
         | I mean, yes, plenty of people don't want to learn new things
         | for bad reasons, but plenty of people have insufficient time
         | and have to make cost/benefit decisions - and you not liking
         | their conclusion doesn't make them wrong - and there are a fair
         | number of people who _were_ all on board with upgrading a
         | decade ago and got bitten by the _then very real_ problems with
         | IPv6 (which mostly boiled down to  "not everything supports it
         | properly, and lots of things fail ungracefully and create weird
         | breakage").
        
         | throwoutway wrote:
         | It's easy to blame IT, but usually they have either business
         | objectives assigned to them or they need to justify it to the
         | business.
         | 
         | So I see the "if it ain't broke don't fix it" more of a
         | business problem and not an IT problem. I worked at one
         | organization where for any networking work, you had to bill
         | that time to a business project (which was usually a customer
         | contract). proponents of IPv6 inside a business probably seem
         | to the business like they've got excited over pointless science
         | projects with nothing to 'bill' their time against
        
         | zokier wrote:
         | > Adding IPv6 has myriad advantages - no need for NAT, proxies
         | or port forwards to share addresses, no need to renumber
         | networks if allocations or upstream change, redundancy, valid
         | security-through-obscurity (imagine port scanning a /64 looking
         | for open ssh ports)...
         | 
         | problem is that adding ipv6 gives none of those. Removing ipv4
         | would do so, but realistically most people are going to run
         | dual-stack of some sort for a while, and as long as that is the
         | case then adding ipv6 is mostly just additive effort.
        
           | stingraycharles wrote:
           | I think most corporate network should be able to do pure IPv6
           | internally, and then tunnel to IPv4 at the gateway.
           | 
           | The number one complaint I hear (and have myself) is that
           | maybe I don't _want_ all devices on my LAN to have public IP
           | addresses. NAT makes security a lot easier to reason about.
        
             | iso1631 wrote:
             | This simple workflow, a new internal network deployed on
             | IPv6 only
             | 
             | Edge Firewalls -- source natting to allow access to IPv4
             | networks
             | 
             | Edge Firewalls -- destination natting to allow access from
             | IPv4 to a service hosted on IPv6
             | 
             | Doesn't seem to widely adopted. It's all dual stack stuff,
             | which means more work and more things to go wrong for no
             | benefit.
             | 
             | Of course there's then the renumbering of your entire
             | internal network every time you change ISP because you're
             | using public IPs rather than private ones
        
             | NavinF wrote:
             | NAT doesn't improve security if port numbers are easy to
             | guess, which is usually the case.
             | 
             | If you wanna block inbound connections, just drop them with
             | your firewall. Most home routers already do this by default
             | and if yours doesn't, you better enable it for IPv4 too.
        
               | stingraycharles wrote:
               | "Block everything" works as long as you aren't actually
               | opening any services on the local network.
               | 
               | If I want to open up a device with a single port, I
               | should open that in the firewall. But wait, my IPv6
               | addresses aren't stateful, so they can change any time.
               | 
               | And then suddenly someone decides to just open port 80
               | and 443 on the main router, and bam! I've just opened up
               | those ports for _all_ IPv6 clients in my LAN.
               | 
               | You think all those IP cameras and ring doorbells were
               | vulnerable when they are behind a NAT? Just wait what
               | happens when they all get assigned public IPv6 addresses.
               | 
               | I'm not saying that these problems are unsolvable. But I
               | think it's important to at least recognize that, yes,
               | this is different than how we did things with NAT, and
               | you now have more tools to shoot yourself in the foot
               | with.
        
               | zamadatix wrote:
               | You should use one of your PDs as a DMZ not putting your
               | externally exposed web server in the same subnet as your
               | IOT or other outbound only devices. If you're hosting a
               | lot of things(tm) you should be using a static DMZ, same
               | as you would on IPv4.
               | 
               | For the more general user case ("I want to host a game
               | session with my friend") I'm not sure if there is
               | something like UPnP for dynamically registering allowed
               | ports without needing to actually do any NAT work but
               | that would certainly seem useful.
        
               | spookthesunset wrote:
               | > you now have more tools to shoot yourself in the foot
               | with
               | 
               | And the tools for managing IPv6 firewall rules suck on
               | "SMB grade" stuff like ubiquiti and are virtually non-
               | existant on any consumer grade router. If I have to SSH
               | into the router and treat it like a "real" router to set
               | up IPv6 firewall rules... it is never gonna fly for
               | anybody who isn't proficient with "real" routers (i.e.
               | >99% of the world).
               | 
               | Hell I'm pretty sure comcast's cable modem doesn't even
               | have IPv6 firewall capabilities and if they do it is
               | default wide open. Thats not what I want. I have no
               | interest in outsiders being able to ping hosts on my
               | network or even know of their existence. I have no
               | interest in letting random IoT devices expose open ports
               | to the entire world (by default).
               | 
               | IPv6 is cool and all, but no consumer gear sets it up
               | even remotely secure. At least with NAT a "script kiddy"
               | grade attacker won't see what is behind your router. NAT
               | isn't perfect but it solves a lot of problems. Not so
               | with IPv6.
               | 
               | Honestly I just don't really see IPv6 replacing IPv4. It
               | introduces too many problems and offers too little
               | benefit. Whatever actually replaces IPv4 will either need
               | to be 10x better than IPv4 in every way or be a
               | completely transparent migration that works with IPv4
               | "but with more addresses".
        
               | X-Istence wrote:
               | > Hell I'm pretty sure comcast's cable modem doesn't even
               | have IPv6 firewall capabilities and if they do it is
               | default wide open. Thats not what I want. I have no
               | interest in outsiders being able to ping hosts on my
               | network or even know of their existence. I have no
               | interest in letting random IoT devices expose open ports
               | to the entire world (by default).
               | 
               | Comcasts cable modem also doesn't have any firewall for
               | IPv4... it's a cable modem, it passes packets.
               | 
               | Your CPE (customer premises endpoint) is where the
               | firewall lives.
               | 
               | > IPv6 is cool and all, but no consumer gear sets it up
               | even remotely secure. At least with NAT a "script kiddy"
               | grade attacker won't see what is behind your router. NAT
               | isn't perfect but it solves a lot of problems. Not so
               | with IPv6.
               | 
               | Most newer consumer gear that does IPv6 blocks all in-
               | bound traffic on IPv6, just like it does on IPv4.
        
               | spookthesunset wrote:
               | > Comcasts cable modem also doesn't have any firewall for
               | IPv4... it's a cable modem, it passes packets.
               | 
               | Most of the new stuff comcast ships is an "all in one"
               | device that acts as an access point, a router and a cable
               | modem. You can buy third party cable modems that do what
               | you describe but what comcast gives you is much more
               | fancy.
        
               | pixl97 wrote:
               | You should almost always buy a 'dumb' cable modem and
               | have your own router that you manage behind it. These
               | devices are commonly behind on firmware and may have
               | completely insecure settings that you'll never have
               | insight into.
        
               | nomel wrote:
               | Having an outdated firmware (which could be solved by
               | mandatory updates from the ISP, which appears to be the
               | direction AT&T is going) is still much better than having
               | no firewall at all. An incredible minority of people, who
               | "manage" their household internet access are aware of any
               | of this.
        
               | deadbunny wrote:
               | > And the tools for managing IPv6 firewall rules suck on
               | "SMB grade" stuff like ubiquiti and are virtually non-
               | existant on any consumer grade router. If I have to SSH
               | into the router and treat it like a "real" router to set
               | up IPv6 firewall rules... it is never gonna fly for
               | anybody who isn't proficient with "real" routers (i.e.
               | >99% of the world).
               | 
               | Umm, the IPv6 firewall interface is exactly the same as
               | the IPv4 firewall interface on UniFi[1].
               | 
               | 1. https://i.imgur.com/waISjwe.png
        
               | nitrogen wrote:
               | It's not just about inbound connections, people also
               | generally don't want to have their outbound devices
               | clearly visible by counting unique IPs, or MAC addresses
               | (and thus manufacturer) of devices sent out with every
               | packet when MAC is used to generate the address, or
               | another globally unique identifier for ad networks to
               | track.
        
               | Notanothertoo wrote:
               | This is why I haven't swapped, but I didn't realize
               | they've accounted for this at the client level. Makes
               | sense, still makes me think about IoT devices though and
               | things I don't have 'control' over like my chrome cast.
        
               | X-Istence wrote:
               | With IPv6 and SLAAC your external IPv6 address changes on
               | a schedule using privacy extensions...
               | 
               | Mine at home is configured to change every 30 minutes.
        
               | kstrauser wrote:
               | I think all major OSes have privacy extensions enabled by
               | default, and therefore use random addresses that change
               | regularly.
        
               | tolien wrote:
               | As sibling points out, that's already covered by the IPv6
               | privacy extensions, which every major OS has some support
               | for [1]
               | 
               | 1: https://datatracker.ietf.org/doc/html/rfc4941
        
               | thrashh wrote:
               | NAT sucks but is harder to misconfigure.
               | 
               | I've never accidentally let something through NAT.
               | 
               | But accidentally not configuring a firewall? Everyone
               | does that and has done that and will forever do it.
        
               | blibble wrote:
               | there's plenty of instances of shitty applications
               | setting up massive port forwarding rules using upnp
        
               | BenjiWiebe wrote:
               | I hear this and I'm always curious how this happens. The
               | Linux distributions I've used, the home routers I've
               | encountered, etc, all default to a restrictive firewall
               | that only needs to be changed if you want stuff allowed
               | through.
        
               | withinboredom wrote:
               | The thing is, once you start to do any complicated
               | firewall setup where defaults can no longer be
               | restrictive, you are bound to screw it up at some point.
        
               | mentat wrote:
               | What kind of firewall work didn't have default drop? Once
               | you take that off the table you really do have a problem
               | but I've only seen that one in 20 years of professional
               | work.
        
               | withinboredom wrote:
               | I've had to do it fairly recently due to a lot of dynamic
               | bridges and routing on the internal network vlan. I
               | wanted to allow all traffic through the vlan from any
               | device. However, wanted a default drop on the external
               | interface.
        
               | X-Istence wrote:
               | Once you are working with VLAN's you are out of the
               | bailiwick of consumer hardware, and you should be looking
               | at more enterprise grade gear.
               | 
               | At that point having a default drop on the external
               | interface and different rules for traffic traversing
               | VLAN's is entirely possible, in fact that is what it is
               | designed and built to do.
        
               | withinboredom wrote:
               | My consumer router has vlan support...
        
               | nunez wrote:
               | Yeah, incorrect firewall rules are a HUGE problem at
               | super large companies that aren't doing infra-as-code at
               | scale yet.
               | 
               | Sysadmins/server engineering/DevOps/SRE, Networks, and
               | Security are usually hard silos at big companies.
               | 
               | "DevOps" gets a request from an app team to open a port
               | between subnet A and subnet B.
               | 
               | DevOps asks Networks to do it. Security needs to approve
               | it before Networks can do it (usually). A cohort of VPs
               | somewhere need to approve it if those subnets are
               | "production" (i.e. subject to serious fines if the data
               | therein fails audit).
               | 
               | Networks outsources the request to their global services
               | team in India/Phillippines/China/Brazil since it's
               | literally a single command, but they are done in bulk.
               | These changes are only done afterhours, partly because of
               | outsourcing latency, partly because of regulations.
               | 
               | The firewall person types in the wrong port. Emergency
               | change request gets filed to fix. Fixed in 1-3 days after
               | the CTO/CIO and some SVPs approve it (and maybe yells at
               | people for wasting their time).
               | 
               | The requester asks for the wrong port. Too bad, so sad,
               | you're waiting another week.
               | 
               | The app team asked for the wrong port. Same outcome as
               | the DevOps person.
        
               | yakkers wrote:
               | As far as consumer routers go, wouldn't it be trivial to
               | re-tool the usual port forwarding interface to simply
               | accept connections to a specific address-port? That
               | combined with a internal block-all-inbound rule would be
               | quite hard for a user to footgun themselves horribly
               | with.
               | 
               | From a quick search, UPnP seems capable of automating
               | this for user convenience, especially with stateless
               | addressing.
        
             | redprince wrote:
             | > I think most corporate network should be able to do pure
             | IPv6 internally, and then tunnel to IPv4 at the gateway.
             | 
             | With the amount of legacy applications and systems
             | populating the typical internal network that idea won't be
             | going far.
             | 
             | Where IPv6 actually can be used and should be deployed in
             | addition to v4 is in the perimeter networks. Offering or
             | being able to use services on the internet over v6 (via
             | proxy) overcomes the real shortage of ipv4 addresses in the
             | internet at large.
             | 
             | I expect internal networks to be last places to be moved to
             | IPv6 only.
        
             | nunez wrote:
             | IPAM, subnetting and firewalls still exist, though. That's
             | just a lazy excuse.
        
             | redprince wrote:
             | > The number one complaint I hear (and have myself) is that
             | maybe I don't _want_ all devices on my LAN to have public
             | IP addresses.
             | 
             | This isn't a goal in itself. The formerly problematic and
             | unwanted side effects of NAT, namely a broken peer to peer
             | relationship of hosts on the internet, are now understood
             | as a feature. Machines were forced by this technology to be
             | clients and the initiators of all connections to the
             | internet. Historically this has interfered greatly with
             | several internet protocols (ftp, IRC DCC, p2p file sharing,
             | ...) all mostly dead now or reworked to operate in a world
             | full of NAT gateways.
             | 
             | IPv6 would reverse this state of affairs. If machines need
             | to be denied the server role, this can be enforced by a
             | firewall. As far as tracking of clients by IP goes, dynamic
             | address assignment via DHCP or IPv6 privacy extension take
             | care of that.
        
               | imoverclocked wrote:
               | One can still have intentionally unroutable addresses in
               | IPv6.
        
               | tsimionescu wrote:
               | Sure, but then you're again on par with IPv4+NAT in the
               | area of connectivity - no worse, but no better. So why
               | switch?
        
               | gumby wrote:
               | Because you have all the overhead of NAT plus losing
               | functionality that cannot operate through NAT. If all you
               | want is to have addresses that done leave the local net,
               | just do that.
               | 
               | You'll lose weight in a famine but nobody would suggest
               | it as a diet plan.
        
               | gumby wrote:
               | > The formerly problematic and unwanted side effects of
               | NAT, namely a broken peer to peer relationship of hosts
               | on the internet, are now understood as a feature
               | 
               | A feature? I've never heard that. If you want to break
               | the end to end nature of the net you can do that in your
               | router, easily and more powerfully, without all the
               | overhead of NAT.
               | 
               | The net has turned back to the old mainframe days, and
               | things like NAT make it hard to go the other way.
        
               | DarylZero wrote:
               | > I've never heard that.
               | 
               | It was in the parent comment!
        
         | ipaddr wrote:
         | The benefit of switching doesn't outweigh the costs yet. The
         | switch to ssl was largely over google rankings vs greater
         | security. What is going to be the reason people switch?
         | 
         | Many think cost of ip4 addresses but that hasn't panned out
         | with solutions like NAT.
        
           | danpalmer wrote:
           | That's only one side of the issue, the server side. There's
           | also the client side to consider. Carrier-grade NAT for
           | mobile/home use is expensive and harder to run than just
           | giving everyone an IP address, and generally means a lower
           | quality connection so you can't charge as much as an ISP,
           | which is why ISPs are increasingly using IPv6. They otherwise
           | need a lot of IP addresses!
        
             | vetinari wrote:
             | ISPs are also making it more difficult to themselves: if
             | there is a support for IPv6 at all, it is DS-lite, not full
             | dual stack.
             | 
             | So let's say I'm willing to migrate to IPv6, but I still
             | need IPv4 for some reason (maybe I need to do the migration
             | with multiple independent ISPs and every single of them is
             | traveling at different speed wrt IPv6). This approach makes
             | it impossible for me to switch where it would be possible,
             | I cannot drop IPv4 yet, CGNAT-ed connection is unusable,
             | but also I cannot use IPv6 where I otherwise could.
             | 
             | So I stay with IPv4.
        
           | IgorPartola wrote:
           | So basically if Google added IPv6 support into its ranking
           | algorithm we would get adoption virtually overnight.
        
             | eppp wrote:
             | No, because isps dont care about page rank. I have to
             | operate a small isp. IPv6 solves nothing for us and just
             | makes even more problems. The comments in here keep saying
             | that ipv6 will fix everything but it is hogwash. It just
             | means I have to support two things instead of one. IPv4 on
             | the internet will not go away even if I do the ipv6
             | transition perfectly.
             | 
             | It is one of the more frustrating parts of trying to
             | explain why we don't all just jump to do this.
        
               | IgorPartola wrote:
               | That's fair. My ISP not only doesn't provide IPv6 but
               | actively blocks using 6to4/6in4. They claim they don't
               | but I can clearly see that they do. It's bad.
        
               | vetinari wrote:
               | Cable modem? Some Intel Puma 6 modems have a bug, where
               | traffic over protocol 41 (6in4) is very slow.
        
               | mhitza wrote:
               | What problems do IPv6 cause for your small ISP?
        
               | eppp wrote:
               | I have an IPv6 block from ARIN. Now what?
               | 
               | Think of all of the hours I have to spend researching the
               | following and implementing it:
               | 
               | 1. Does all of the intermediate equipment support it
               | 
               | 2. Does my IPAM support it
               | 
               | 3. How do I even give ipv6 addresses to my ONTs?
               | 
               | 4. How do I keep track of all of the address assignments
               | for x months
               | 
               | 5. Does my staff even understand how ipv6 works?
               | 
               | 6. Does the off hours call center understand it?
               | 
               | 7. Build the servers and add them to all of the
               | monitoring, backups, do updates on them
               | 
               | 8. What if I do this and the choice for ipv6 dhcp was
               | wrong and in a year I have to redo it all
               | 
               | etc etc
               | 
               | There are no good answers for any of this that I have
               | seen. There are sometimes 5+ options for everything to do
               | with ipv6. How do I even weigh the pros and cons of
               | approaches I have never used before.
               | 
               | Its hundreds of man hours at a minimum for no benefit
               | other than to be ideologically on the correct side of
               | technology. It will continue to work as it is now with
               | absolutely no hours or risk for 10+ years at least.
        
               | IgorPartola wrote:
               | Isn't it incredibly expensive to get your own block?
        
               | eppp wrote:
               | Since we already have an ASN, its free basically. I
               | already have one. Its at least a /32 and maybe a /28.
               | 
               | My upstreams support it, my ONTs support it but there
               | isnt a nice ipv6 dhcp server with logging and a lookup
               | interface that I have found yet. It probably exists but I
               | don't know what it is.
        
               | toast0 wrote:
               | IPv6 blocks are usually quite reasonably priced. You
               | might even get them for free, if you're already paying
               | maintenance on an IPv4 block (which are expensive to
               | obtain these days)
        
               | daydream wrote:
               | I completely understand that it's a huge amount of work.
               | But v6 has been around for 20 years. Spread across
               | decades the work becomes a much smaller lift.
        
         | twistedpair wrote:
         | If I provided users with an IPv6 block to allowlist for my
         | apps, I think most IT directors' heads would explode, but
         | _everything_ works with 32 bit CIDR ranges.
         | 
         | I certainly support it, but I'm not sure we'll see an end to
         | NAT for some time, even with an IPv6 option.
        
         | quaintdev wrote:
         | Some big nation should decide to switch off IPv4 over a course
         | of maybe a month and maybe we will start seeing servers
         | deploying IPv6 then.
        
           | yjftsjthsd-h wrote:
           | Why and how would they even do that?
        
         | jl6 wrote:
         | > "we fear change"
         | 
         | Regardless of the IPv6 situation, IT departments take this
         | position for a reason. It might be obvious to individual
         | engineers how to safely deploy IPv6 on their home network if
         | they fully understand all the moving parts. But large
         | corporations with deep legacy to maintain don't have the luxury
         | of running a fully understood system. Isn't that a big risk?
         | Hell yeah, and of course they've all got modernization projects
         | running. But in the meantime, they fear change - legitimately.
        
         | roamerz wrote:
         | Calling people ignorant because you don't agree with their
         | opinions or reasons is a non starter for constructive
         | discussions. Using IPV4 has never ever caused me a problem and
         | I will never ever run out of addresses. I prefer to focus my
         | time on real issues that actually affect end users and improve
         | their experiences.
        
         | tyingq wrote:
         | There's a fair amount of "who goes first" or "who sees that it
         | works end-to-end". My personal experience has been several
         | situations where some piece of software that doesn't work, or
         | is slow, suddenly works when I disable ipv6. That includes vpn
         | client software I had to use for a job, dns configuration at
         | another job, a mesh network for some hobby thing, etc.
         | 
         | Had I spent the time to dig into it, I'm sure I'd have found
         | the issue. And it probably wouldn't have been directly a true
         | ipv6 problem. But I had more important things to deal with, so
         | it moved to number 11 on my "top 10 list".
         | 
         | I'm guessing I'm not alone in that. So while individual teams
         | and products might be working to support it, end users often
         | see that it doesn't, because of some peripheral thing that's
         | misconfigured, doesn't have support, etc. So they give up,
         | which reduces perceived demand.
        
           | withinboredom wrote:
           | If you don't have AAAA records and you don't have Interfaces
           | listening to those addresses. You won't "see" ANY "demand."
           | So since they don't see ipv6 traffic, they think there's no
           | demand for it. It's a self-fulfilling statistic.
        
             | zamadatix wrote:
             | It's far more likely the statement refers to a lack of user
             | tickets, project requests, or compliance requirements as
             | that's normally how IT finds out what to do next. I've
             | never seen an IT staff with so little to do they are
             | monitoring the network looking for packets for ideas of
             | what they should implement next instead of implementing
             | things they've been trying to get time for for the last 5
             | years. Link utilization maybe but that's a completely
             | different beast.
             | 
             | Not to mention it's extremely hard to know how to check the
             | statistic you described without becoming aware you don't
             | have the things needed to generate the statistics so this
             | reasoning kind of rules itself out with the exception of
             | AAAA records - you'll actually see those requests even if
             | all you have is A records on an IPv4 only DNS server.
        
         | pm90 wrote:
         | > My favorite is, "we have no record of people trying to use
         | IPv6" - yes, that's real :D
         | 
         | Have you ever worked at a IT department for a medium to large
         | company? It's usually a total shit show. IT gets blamed (justly
         | or unjustly) for any issue with computers. As a result they
         | become rather thick skinned and incredibly conservative in the
         | projects they undertake.
         | 
         | So it's not surprising that folks are unwilling to spend time
         | on something they don't have prior art for, haven't operated
         | before, and doesn't offer significant benefits over what they
         | already have.
        
         | belter wrote:
         | "Comparison of IPv6 support in common applications"
         | 
         | https://en.wikipedia.org/wiki/Comparison_of_IPv6_support_in_...
        
         | otabdeveloper4 wrote:
        
           | mrkurt wrote:
           | I mean, the original purpose of NAT was to let you move hosts
           | between networks without renumbering them. No one really does
           | that though, your laptop or phone happily renumber themselves
           | when you move networks.
           | 
           | No one's going to use NAT for keeping IPv6 between networks.
        
           | fishtacos wrote:
           | Default deny from external access isn't an IPV4 NAT-only
           | feature, but it does come out of the box.
           | 
           | The same would need to be set up for IPv6 and move on past
           | that.
           | 
           | It's a firewall issue, not a protocol issue.
        
             | BenjiWiebe wrote:
             | The devices I've seen have default deny for IPv6 as well.
        
           | justsomehnguy wrote:
           | Do you know you can have DENY FROM ALL by default in any IPv4
           | firewall?
           | 
           | Do you know what you would be hardly pressed to find a router
           | without firewall not only in the year 2022, but in the year
           | 2012 too, when there was 10G *switches* capable of routing
           | AND firewalling traffic almost at the line rate?
        
             | otabdeveloper4 wrote:
             | Firewall and NAT are orthogonal. You need both.
             | 
             | Exposing your LAN configuration for the whole world to see
             | is insanity. (Yes, we sometimes do this, but only because
             | we still don't have sane VPN solutions here in the year
             | 2022.)
        
           | tyingq wrote:
           | I'll admit to not understanding this position. Without NAT,
           | you could do the same sort of firewalling, where the inbound
           | allow list is driven dynamically. The only thing I can think
           | of is that not using NAT exposes more detail about an
           | internal network. Is that the reason you're hinting at, or is
           | the reason something else?
        
             | 300bps wrote:
             | Not OP but that's how I think of it.
             | 
             | If my internal network is 10.0.0.0/8 and I have 100,000
             | hosts and a single IPV4 address that they all appear to be
             | to the public Internet, I'll sleep a lot better than if I
             | had all 100,000 hosts with public routable IPV6 IP
             | addresses attached to them.
             | 
             | Yes, you can depend on a firewall to protect you but at the
             | very least it exposes information about your internal
             | network and at worst opens you up to future firewall flaws.
             | 
             | I remember the days when people used to have every system
             | have it's own public IP address. People would scan for
             | broadcast addresses of their networks and we got Smurf
             | attacks as a result. Obviously those wouldn't work with
             | properly firewalled hosts but it still scares me.
        
               | fishtacos wrote:
               | This is why we have firewalls. My pfSense router e.g.
               | blocks external access by virtue of it being a firewall
               | with sensible defaults.
               | 
               | All routers w/ firewalls will/should have them.
        
               | pm90 wrote:
               | Firewalls are fine but having the ability to make
               | machines unroutable is even more powerful, no?
               | 
               | While I get that firewalls are probably safe like 99.99%
               | of the time... I've gotta say, I just don't trust
               | software to not have vulns of some sort that someone
               | important already knows how to break. So eg for a
               | corporate network I would be hesitant to do this, for my
               | personal network not so much (unlikely that a 3 letter
               | agency gives a shit about what I do).
               | 
               | Additionally. Firewall changes can sometimes fail for
               | whatever reasons so you might have accidentally exposed a
               | node publicly for some time.
               | 
               | Making those nodes not reachable from the internet seems
               | prudent. It's like your office building has a public
               | address but your office assignments don't need to be
               | public.
        
               | zekica wrote:
               | No. There is no difference between the two from a
               | security point.
        
               | justsomehnguy wrote:
               | >Firewalls are fine but having the ability to make
               | machines unroutable is even more powerful, no?
               | 
               | For the whole world there is absolutely no difference
               | betwen routable address, non-routable address or even an
               | absense of the machine... behind a firewall with drop all
               | on a public interface.
        
               | 300bps wrote:
               | Your statement doesn't address the point you are
               | responding to so it makes me think you completely missed
               | the point you are replying to.
               | 
               | You are correct _in theory_. What you don't seem to be
               | taking into consideration are firewall vulnerabilities or
               | other unknown things that could happen that make it
               | different from a practical standpoint.
               | 
               | I started an ISP from the ground in 1996. I've seen a lot
               | of weird stuff. You seem to just hand waive it away like
               | firewalls are this perfect bastion of security.
               | 
               | Maybe you have more experience than I do?
        
               | blibble wrote:
               | where do you think the NAT and associated connection
               | tracking is occurring exactly?
        
               | floatboth wrote:
               | Even firewalls are just a last resort defense IMO. The
               | primary thing is not having any crap listening on ports
               | in the first place.
        
               | mrkurt wrote:
               | Anything smaller than a IPv6 /48 is effectively
               | unroutable. Your ISP has to route smaller blocks, like
               | /64s, privately (because only /48s hit public bgp). And
               | then you have to route the /64 they assign you privately
               | once again.
        
               | mrkurt wrote:
               | IPv4 with nat is effectively routing your 100,000 hosts
               | through one of 4,294,967,296 possible IP prefixes (a
               | /32).
               | 
               | IPv6 with a /64 routes one of
               | 18,889,465,931,478,580,854,783 possible IP prefixes to
               | your router. Everything that happens behind that is
               | opaque. There are so many IPs in that prefix that people
               | can't even guess which ones you're using. It's easier to
               | guess internal IPv4 NAT addresses.
               | 
               | The internet can't see your IPs. "Publicly routable"
               | doesn't mean much when you're talking about prefixes.
        
               | otabdeveloper4 wrote:
               | Unless you're planning to assign random IPv6 addresses
               | for each connecton then it's not at all the same thing.
               | 
               | And anyways, when you have a NAT you're probably routing
               | traffic through a level 4 balancer or jumphost or using a
               | VPN somewhere in your LAN.
        
               | blibble wrote:
               | > Unless you're planning to assign random IPv6 addresses
               | for each connecton then it's not at all the same thing.
               | 
               | SLAAC
        
               | Dylan16807 wrote:
               | SLAAC has an option to randomize, but it's a lot slower
               | than per-connection.
        
               | mrkurt wrote:
               | We assign IPv6 deterministically. Incrementing them is
               | the most boring way to use IPv6 space.
               | 
               | You can also just start in the middle of a block and make
               | a sequence of 10,000 IPs effectively unguessable.
               | 
               | I don't buy that keeping addresses private has much
               | value, but IPv6 still isn't worse than NAT in that
               | respect.
        
               | doubleunplussed wrote:
               | As soon as one of the computers in the subnet initiates
               | traffic outside the network, its IP address becomes
               | public knowledge though, right? Doesn't matter how large
               | the space is, that information leaks, whereas with NAT it
               | doesn't.
        
             | Hnrobert42 wrote:
             | Some of our service providers require us to provide the IP
             | addresses of our services to them for them to safelist.
             | It's stupid, but it's not something we can control.
             | 
             | Rather than constantly update them as our servers change,
             | we route through a NAT. I wouldn't know how to do it with
             | IPv6. Maybe the service provider could safelist a subnet?
        
               | pm90 wrote:
               | They probably wouldn't support that. Most non software
               | heavy companies outsource these sorts of projects and to
               | make changes to their systems requires a bunch of upfront
               | capital costs which can be expensive so they will push
               | back against changes unless you are big enough to force
               | them to or you convince them of the merits of such
               | changes.
        
               | miyuru wrote:
               | >Maybe the service provider could safelist a subnet?
               | 
               | Yes, thats what prefixes are for. Although its
               | unpractical in IPv4 world, in IPv6 it is the way to
               | whitelist a range of ips.
        
               | antxxxx wrote:
               | Depending on the type of connection it's fairy easy to
               | set up squid as a proxy for outbound connections so
               | everything appears to come from the squid box which can
               | have a static address and can be added to an allow list
        
             | justsomehnguy wrote:
             | It's extremely funny how a network with NAT needs hole
             | punching in the firewall and network without NAT sudenly
             | doesn't have firewall at all. Like OK, in 1995 a router
             | would have been a dedicated machine or appliance, but since
             | 2005 anyone can buy a sub $30 device which routes,
             | firewalls, provides a bunch a of (unnecessary) services...
             | but suddenly incapable of firewalling if IPv6 is involved.
        
               | spookthesunset wrote:
               | > but suddenly incapable of firewalling if IPv6 is
               | involved.
               | 
               | It's been a few years but I've yet to see a consumer
               | grade router that lets you mess with IPv6 firewall rules.
               | I don't even know what these routers use for a default
               | policy.
               | 
               | They all seem to have web ui's for IPv4 firewalls and
               | port forwarding though...
        
               | vetinari wrote:
               | Ever seen an average IPv6 firewall, even on $500 devices?
               | 
               | You can have dynamic prefix that can change with every
               | moment on your wan interface, but then you have static
               | IPv6 rules and you cannot specify something like _use
               | current prefix_ there.
               | 
               | So I understand if the first reaction is _screw that_.
        
             | otabdeveloper4 wrote:
             | Yes, of course.
             | 
             | Exposing your LAN confguration for the world to see is
             | insanity, it's like hiding your private SSH keys in a
             | password-protected Excel file.
             | 
             | And yes, you need both NAT and firewall. They're
             | complimentary technologies and do not replace each other.
        
           | [deleted]
        
         | rr808 wrote:
         | NAT is a very simple idea that works very well. In fact for my
         | private network with 20 odd devices I'd prefer to keep it.
        
           | xibo9 wrote:
           | The problem is, it is NOT a simple idea, but one that
           | requires a lot of relative heavy lifting with deep packet
           | inspection for a lot of protocols that have to deal with the
           | spaghetti that is NAT.
        
             | spookthesunset wrote:
             | Yeah but even if it isn't simple it is mostly a solved
             | problem at this point. NAT has been around for, what, 15
             | years now?
             | 
             | And quite honestly the default configurations for IPv6 on
             | consumer routers is "wide the fuck open"--which is not at
             | all what I want. But if they don't make it "wide the fuck
             | open" suddenly you are asking normal people to learn how to
             | punch holes in their firewall.
        
               | fsh wrote:
               | I have never seen a consumer IPv6 router without a
               | restrictive firewall enabled by default. Could you give
               | some examples where this is not the case?
        
               | spc476 wrote:
               | Pv6 and NAT were developed in the mid-90s. They've both
               | been around for far longer than just 15 years.
        
             | MrStonedOne wrote:
        
         | dheera wrote:
         | > no need for NAT
         | 
         | Yeah everyone says this but I can't access any ports on my IPv6
         | address from outside my home network.
         | 
         | Back to IPv4 + NAT + port forwarding, I guess.
         | 
         | I have bigger problems I need to solve in my life right now.
         | When one day I can just ssh <my-ipv6-address> from the outside
         | I'll do that. Thanks.
         | 
         | Also, there's the DNS problem. I can remember 10.0.0.3,
         | 10.0.0.20, etc. pretty damn easily. I can't remember
         | 8cef::fasd:8000:c00a:::99aa:::::81/42:8fe that easily.
         | 
         | Which is an issue when things like 'foobar.local' don't work
         | half the time. I have the IPv4 addresses of all my internal
         | machines memorized thanks to the the fact that .local just
         | doesn't work, period.
        
           | bombela wrote:
           | .local not working might be your router trying to be helpful
           | and snoop multicast to limit it to pairs of devices.
           | Something about iptv optimization or whatever I don't really
           | understand. Since I turned this feature off .local works as
           | it should.
        
           | zekica wrote:
           | You are using it wrong.
           | 
           | You can't access a service on a server on your local network
           | using your router's global IP. You should use server's global
           | IP address (and open the port for that IP on the firewall).
           | 
           | If your server uses SLAAC, it will always use the same local
           | address (whether using EUI-64 or stable privacy), or you can
           | configure it manually. In either case the address won't
           | change.
           | 
           | NAT made you think in a different way, but if you started
           | with IPv4 before there was NAT, this setup is exactly the
           | same as it was with IPv4 a long time ago.
        
             | dheera wrote:
             | Too much work.
             | 
             | If I type ifconfig on my machine I only have one 'inet6'
             | address and it isn't reachable from the outside.
             | 
             | The relevant people who want to popularize IPv6 should make
             | that "just work". Until then IPv4 works for me, and a port
             | forward is easy to understand, I don't need to google what
             | SLAAC and EU-64.
             | 
             | They advertise it as "oh you don't need a NAT" but in
             | reality IPv4+NAT is easier to deal with.
             | 
             | Most of us have actual jobs and don't have time to also be
             | devops people.
             | 
             | I realize this sounds like a shitpost, but this UX is
             | exactly why IPv6 isn't popular yet. If you want something
             | to be popular, you need to make it _easier_ not harder than
             | the current thing everyone uses.
        
               | Symbiote wrote:
               | Half the discussion is FUD that a consumer router
               | wouldn't have an IPv6 firewall.
               | 
               | Your router, like every other, has a default deny
               | firewall for IPv6. You'll find the settings near to where
               | you set up IPv4 port forwarding. My router calls it
               | "pinholing" or something.
               | 
               | Then you can SSH directly to the servers you allow access
               | to, using port 22 for all of them if you wish.
        
               | dheera wrote:
               | I tried enabling IPv6 on my router just now. It asked me
               | for a delegation size. How TF do I know. I just randomly
               | put in 60. It's what a google search told me to put in.
               | Save changes.
               | 
               | Go to main screen. Still only shows my IPv4 WAN address.
               | No IPv6 "pinhole" setting near the port forwarding.
               | 
               | Back to making breakfast and doing what I needed to
               | actually do.
               | 
               | I use a UDM Pro by the way.
        
               | Symbiote wrote:
               | Sorry, I thought you were asking about a home broadband
               | connection with the typical basic router supplied by the
               | ISP.
               | 
               | The UDB Pro looks like something for a small/medium
               | business, so you presumably have a business connection.
               | You'd need to ask your ISP for the configuration, as it
               | will depend on what service they're providing. (Just like
               | for IPv4 you'd need configuration if the ISP is providing
               | you with 4, 16, 32, ... IPv4 addresses -- also a common
               | situation.)
               | 
               | If ifconfig is showing IPv6 addresses starting with
               | fe80:, these are local/private, a bit like 169.254.x.y
               | IPv4 addresses.
               | 
               | So far, all global/routable IPv6 addresses begin with 2.
               | 
               | (And for most home users, IPv6 is just as easy as IPv4,
               | i.e. they don't know anything about either. After a test
               | period, ISPs that support IPv6 generally enable it for
               | all the normal home users -- it saves them money! That it
               | is the default is how we got to 35% of Internet users
               | using IPv6.)
        
               | spookthesunset wrote:
               | Totally agree. The UX for IPv6 sucks. Every time I poke
               | with it I get worried I'm exposing the guts of my
               | internal network onto the internet. With NAT, at least I
               | know nothing is getting in without me intentionally
               | punching a hole. With IPv6 to do the same I have to go
               | fiddle with the router's command line interface and rules
               | by hand. And even then who knows if I fucked something up
               | or missed something... its just a lot of work.
               | 
               | There is no web UI for managing IPv6 firewall rules but
               | there is for IPv4. On the consumer grade routers I've
               | touched there isn't even a way to configure the IPv6
               | firewall rules (and again, they all offer web UX for IPv4
               | rules).
        
               | Symbiote wrote:
               | The interface on the router provided by the UK's largest
               | ISP is almost identical to the interface for IPv4 port
               | forwarding: https://imgur.com/a/NXqwoA6
        
               | spookthesunset wrote:
               | Awesome!
               | 
               | I wish my edgerouter had something like that...
        
               | [deleted]
        
         | iso1631 wrote:
         | I can't go v6 only, so why double my workload by supporting
         | ipv4 and ipv6.
        
         | throw0101a wrote:
         | > _What 's really interesting is how many of these "we fear
         | change" IT people don't realize they're already using IPv6 on
         | their phones every day, with a majority of the sites they
         | visit._
         | 
         | For example see the video "T-Mobile's path to IPv6 Only":
         | 
         | * https://www.youtube.com/watch?v=nNMNglk_CvE
        
           | Tijdreiziger wrote:
           | Wow, interesting to see such a video coming from T-Mobile. We
           | have a DSL connection with T-Mobile Netherlands and they
           | still don't support IPv6. Any inquiries about this on their
           | community forums are met with a reply of 'there are currently
           | no plans for IPv6 support'.
        
             | X-Istence wrote:
             | T-Mobile here in the US is a mobile provider, they don't
             | have any landline service.
        
               | Tijdreiziger wrote:
               | They used to be just a mobile provider here, but a number
               | of years ago they acquired Vodafone's DSL division. They
               | don't actually own any DSL lines though, they just rent
               | line access from KPN (the country's incumbent telco).
        
             | floatboth wrote:
             | Different countries' T-Mobiles are quite different,
             | especially the US one..
        
         | MrStonedOne wrote:
        
         | Alekhine wrote:
         | Wait, if my phone is IPv6, then what does it mean that a site
         | 'supports' v6? I can get on HN just fine.
        
           | [deleted]
        
           | jakub_g wrote:
           | Websites have separate DNS records for ipv6 (AAAA record) and
           | ipv4 (A record). Since ipv6 is not universally supported, the
           | de facto expectation is that if website has ipv6 DNS record,
           | it should also have an ipv4 one for the users who can't talk
           | ipv6.
           | 
           | Your device's network stack first learns if your mobile ISP
           | supports ipv6 or not, and based on that and DNS reply decides
           | how to connect to a given website.
        
           | throw0101a wrote:
           | > _Wait, if my phone is IPv6, then what does it mean that a
           | site 'supports' v6? I can get on HN just fine._
           | 
           | It means that the phone doesn't have to talk through a
           | network-translation box, which may add latency. For some
           | things (gaming?) this may be important, while for others it
           | may not be.
           | 
           | Further, the price of each IPv4 address is going up, and so
           | having your hosts on IPv6 may allow for the lowering of your
           | costs, which you can pass onto your customers or add to your
           | margin.
           | 
           | About a year ago they were US$ 30/IPv4, and they now seem to
           | be in the $50 range:
           | 
           | * https://auctions.ipv4.global
           | 
           | * https://auctions.ipv4.global/prior-sales
        
             | fpoling wrote:
             | We use VPS from tilaa.com and they charge 2 Euro per extra
             | IPv4 and for the third etc. address per server one needs to
             | submit a technical reason for doing that that they manually
             | review.
        
           | tolien wrote:
           | Does your phone _only_ have a v6 address though? If it did,
           | you would need some kind of proxy (6to4 [1], the most likely
           | example) connecting to HN 's IPv4 address on your behalf.
           | 
           | As the sibling points out, if both site and device support v6
           | the intermediate translation isn't required.
           | 
           | 1: https://en.wikipedia.org/wiki/6to4
        
             | fishtacos wrote:
             | That's exactly what it is. There is always a proxy, which
             | negates part of the argument, but is a very useful tool in
             | transitioning over the next 2 other decades at least... the
             | way this is going.
        
             | Dagger2 wrote:
             | It definitely wouldn't be 6to4; that requires a v4 address.
             | 
             | It'll be NAT64.
        
               | tolien wrote:
               | Ah you're right, 6to4's a 1:1 IPV6 to IPv4 translation.
        
           | nunez wrote:
           | You establish a TCP session with the IPv6 address of that
           | site instead of its IPv4 one by way of getting its AAAA
           | record and your phone having dual-stack networking enabled.
           | 
           | (Most US carriers have IPv6 enabled and issue IPv6 addresses
           | to their phones.)
        
       | rmoriz wrote:
       | Running containers dual-stacked is still surprisingly difficult
       | or annoying.
        
       | zokier wrote:
       | What I haven't quite fathomed with IPv6 is that as a home user
       | without my own AS, am I supposed to use my ISP provided addresses
       | in my internal network? ISP provided addresses that I have no
       | control over and could change at any time? With IPv4, I just use
       | RFC1918 addresses as I like and I have full control over the
       | addresses and their allocation and I can then very easily set up
       | iptables rules, dhcp pools, dns records etc. Then I just NAT at
       | the edge of my network, and the configuration is practically
       | completely isolated from my ISP and whatever addressing they do.
        
         | BitPirate wrote:
         | If you don't have a static subnet, you can still use ULAs.
        
           | BenjiWiebe wrote:
           | Exactly. With IPv6 you are expected to have multiple
           | addresses. Some to access the internet with that may change,
           | some that don't change and aren't globally routable to access
           | your own stuff with. Though you can also (if your router
           | supports it) assign hostnames to your devices so you can
           | access them via their non-static global addresses.
        
         | infiniteloop0 wrote:
        
         | infiniteloop0 wrote:
        
         | franga2000 wrote:
         | IPv6 has private addresses too. In my network, all computers
         | have 3 addresses: public, private and link-local. All local
         | services use the private ones and those never change. (I don't
         | think they're called "private" in the spec, but the idea is the
         | same)
        
         | benttoothpaste wrote:
         | In addition IPv6 has this weird restrictions on which prefixes
         | are valid. For example if your ISP gives you /64 prefix, most
         | consumer routers will not recognize it as valid. And even if
         | you have a very configurable router it will take lots of work
         | to configure that - even though in theory you should have tons
         | of addresses available. And if you get a /128 prefix, good luck
         | that - NATs are apparently disallowed in IPV6 world.
        
           | zamadatix wrote:
           | > For example if your ISP gives you /64 prefix, most consumer
           | routers will not recognize it as valid.
           | 
           | A /64 is the most valid IPv4 prefix there is. Most consumers
           | should be given multiple (usually about 16) and the router
           | starts with the first one.
           | 
           | > And if you get a /128 prefix, good luck that
           | 
           | No kidding, that's a single address subnet!
           | 
           | > NATs are apparently disallowed in IPV6 world.
           | 
           | It's allowed it's just not the right answer in the vast
           | majority of cases.
        
           | mjevans wrote:
           | RIPE approved prefix lengths for end customers are /48, /52,
           | /56, /60, and /64; though the prefixes longer than /56 are
           | strongly discouraged and probably reflect either an ISP that
           | doesn't get IPv6 or that is anti-consumer if they do.
           | 
           | https://www.ripe.net/publications/docs/ripe-690#4-2--
           | prefix-...
           | 
           | ... "Each hexadecimal character in an IPv6 prefix represents
           | one nibble, which is 4 bits. The length of a delegated prefix
           | should therefore always be a multiple of 4.
           | 
           | A single network at a customer site will be a /64. At
           | present, RIR policies permit assignment of a /48 per site, so
           | the possible options when choosing a prefix size to delegate
           | are /48, /52, /56, /60 and /64.
           | 
           | ...
           | 
           | The following sections explain why /48 and /56 are the
           | recommended prefix assignment sizes for end customers.
           | 
           | ...
           | 
           | It is strongly discouraged to assign prefixes longer than /56
           | unless there are very strong and unsolvable technical reasons
           | for doing this."
        
             | tsimionescu wrote:
             | Is RIPE a law? Can they force my ISP to give me a /56 if
             | they're giving me a /128?
        
             | [deleted]
        
           | zekica wrote:
           | NAT is not disallowed in IPv6, it's just discouraged as it
           | breaks end-to-end principle. You can still have stateful
           | firewalls that work for the majority of cases and you can
           | also use NPT (network prefix translation also called 1-to-1
           | NAT) if you want. There is even a RFC specifying on how to do
           | NPT without creating compute overhead for routers by making
           | the packets have the same CRC.
        
             | Spivak wrote:
             | NAT is actually probably preferred too for homelabbers one
             | because you don't have to re-address things ever and also
             | because you can use your whole ISP assignment as a pool of
             | dynamically assignable/attachable public addresses.
        
               | DarylZero wrote:
               | Are you thinking of prefix translation?
        
       | amluto wrote:
       | I'll add one: for servers accessed only via private networks,
       | IPv6 still allows easy use of globally unique addresses. The
       | finance world is full of IPv4 systems using 10.x.y.z, and there
       | aren't enough of those addresses to go around.
        
       | hexo wrote:
       | my ISP uses IPv6. actually with some sort of 4-in-6. i can access
       | v4 and v6 world with no artificial problems.
        
       | yjftsjthsd-h wrote:
       | This seems like a good place to mention a neat trick: If you're
       | behind cloudflare or such, you can probably trivially go _pure_
       | IPv6 on your servers and not even have to worry about NAT because
       | cloudflare will provide v4 to users that use it. So you end up
       | with (your server) -v6- > (cloudflare) -v4/v6-> (users). (Which I
       | admit is a sort of NAT, just not at the IP level)
        
       | dekhn wrote:
       | I noticed that effectively all my home machines support dual
       | stack right now. I decided to make an experiment and move to only
       | IPv6.
       | 
       | It was a huge mess (the autoconfig functionality, naming,
       | routing) that all sort of failed in ways that involved deep
       | hacking to debug. Ultimately I realized that since most sites on
       | the net aren't ipv6, I'd need to NAT or proxy my traffic to them
       | anyway.
       | 
       | Let me know when we're ready to turn off IPv4.
        
       | tomsmeding wrote:
       | > Apparently you can buy IPv6 addresses, use them for the servers
       | on your home network, and then if you change your ISP, continue
       | to use the same IP addresses?
       | 
       | > I'm still not totally sure how this works but it sounds cool.
       | 
       | Naively I would say this is completely impossible without some
       | form of your home router (or ISP?) relaying your traffic, or
       | perhaps telling the sender that I am now actually located in a
       | different subnet somewhere. If anyone can have IP(v6) addresses
       | and keep them and take them with you, then wouldn't that result
       | in an unmanageably large lookup table at routing nodes to know
       | where to route stuff to?
       | 
       | How does that work?
        
         | linsomniac wrote:
         | I believe this might be talking about getting an ARIN
         | reservation, as elsewhere it is mentioned that it is not cheap
         | and points to the ARIN fees page. The list of ARIN requirements
         | includes: "You plan to immediately be multi-homed". So you're
         | going to need to be connected to multiple ISPs that will talk
         | to you via BGP would be my assumption.
        
         | adamcharnock wrote:
         | So this is typically what BGP is for, but this is definitely
         | not something that is typically offered to residential
         | customers, nor even most business AFAIK. This is what you would
         | typically get with a Direct Internet Access (DIA) connection.
         | This is an uncontended connection where to setup a BGP peering
         | with your provider. You then give the provider some
         | documentation proving you own a range of addresses, and they
         | agree to accept those routes from you via the BGP connection.
         | They then advertise that to their upstream providers, and thus
         | the routes propagate to the entire internet.
         | 
         | There are a couple of gotchas though. Firstly, there is
         | generally a minimum prefix size of routes that will be accepted
         | into the global routing table. For IPv4 I think it is a /24,
         | and for IPv6 I think it is a /32. You can get a /32 from
         | regional IP registry (for free?) but you will probably need to
         | become a member which - last time I checked - costs 3-4 figures
         | a year. You can use a private-AS number though, as you'll only
         | have one upstream provider.
         | 
         | The other gotcha is cost. Depending where you are in the world,
         | a DIA connection will cost in the very rough region of
         | (EUR/USD/GBP) 1/megabit/month, although it becomes much cheaper
         | when going from 1gb to 10gb.
         | 
         | Now maybe there is some cool facility that some nice ISPs offer
         | to bypass all this, if so then please let me know. I'm
         | personally skeptical it would be worth their while for the
         | 0.001% of residential customers that would want this service
         | though.
         | 
         | Source: I run a small ISP. I have some industry knowledge, but
         | not loads.
        
         | gnopgnip wrote:
         | You can get your own autonomous system, and take your IPs with
         | you when you change ISPs, or have the same IPs reachable
         | through multiple ISPs. This is possible for both ipv4 and ipv6
         | but ipv6 is much cheaper. Still not really something that makes
         | sense for a residential user. You need to have networking gear
         | that handles routing on the internet, bgp advertisement instead
         | of having your ISP handle it. There are annual fees, you
         | generally need to be on a business plan with the ISP. For ipv4
         | the minimum ASN size is a /24, it costs around $12k to buy the
         | IPs for a /24. Ipv6 ips are free. It also costs around $1000 in
         | annual fees for an ipv4 asn, ipv6 is less. ipv4 ASNs smaller
         | than /24 aren't advertised outside of your current ISP and
         | aren't really portable.
         | 
         | Currently there are about a million ipv4 prefixes advertised.
         | And about 150k ipv6 prefixes. Some older ipv4 equipment has a
         | limit of 1024k, or near 1 million advertised prefixes. This
         | equipment is usually 15+ years old, but still is what runs the
         | internet. Generally equipment that supports ipv6 can support
         | many more networks
        
         | metalliqaz wrote:
         | its possible but it relies on your ISP being willing to route
         | your traffic, and as the article notes, many won't bother
        
       | jlokier wrote:
       | My office ISP is a mobile phone running a wifi hotspot.
       | 
       | (Don't judge, it's faster than the last ADSL connection at about
       | 80Mbit/s on a good day, much cheaper, and the office goes through
       | about 40GB/month no problem.)
       | 
       | The phone has an IPv6 address but no IPv4 address.
       | 
       | Ironic, then, that the hotspot only provides IPv4 to all
       | connected devices, not IPv6. As a result, all connected devices
       | in the office can only use IPv4.
       | 
       | My home ISP is a mobile 4G router providing wifi.
       | 
       | The router doesn't get an IPv6 from upstream, just IPv4, so it
       | only provides IPv4 to connected devices at home. I have no idea
       | if it would provide IPv6 service if it got one from upstream. It
       | is a little strange that it doesn't get IPv6 from upstream,
       | because it's exactly the same type of mobile data contract as the
       | office phone-router is using.
       | 
       | It's 2022. I've had IPv6 on my servers since about 2003.
       | 
       | But aside from my actual phone, I've never had IPv6 on any device
       | I'm using, living at numerous homes, using many and varied ISPs,
       | working at numerous offices, or anywhere else. Not even when
       | travelling.
       | 
       | I had to turn off IPv6 on my mail server, because gmail.com was
       | rejecting mail from it when sent over IPv6, but not when sent
       | over IPv4.
       | 
       | I use LXD and Docker on some of my servers for containers, and
       | libvirt/KVM for VMs. In theory they support IPv6 but in practice
       | it's easier to work with IPv4 address or port forwarding with
       | them. That means the containers and VMs are only reachable from
       | the internet over IPv4, even when the host servers have IPv6.
       | 
       | All together, anything I do to support IPv6 ends up poorly tested
       | because it's not really used, and everything has to be done with
       | IPv4 in parallel anyway.
       | 
       | I still have IPv6 on my servers, and DNS configured
       | appropriately. But as it virtually never gets used, it seems a
       | bit pointless. Sometimes I don't set up IPv6 on a new server
       | straight away, and nothing is missed.
        
       | iqanq wrote:
        
       | tolien wrote:
       | There's already a lot of FUD around IPv6 and I'm not sure that an
       | article which seems to amount to a survey on Twitter really moves
       | the conversation forward much.
       | 
       | Clearly there's pain points to rolling out v6 (although I'd
       | question how many of them are still an issue outside the glacial
       | pace of Enterprise IT) and we'd be better trying to address that
       | than re-hash the same old arguments.
       | 
       | Edit: not much more than 2 weeks ago we had this chestnut [1]
       | where Nintendo was telling you to forward thousands of UDP ports
       | to a Switch in order to play online but still we hear "but NAT
       | works fine for me".
       | 
       | 1: https://news.ycombinator.com/item?id=29919228
        
         | zamadatix wrote:
         | I think the decades of dominance of UDP/TCP over IPv4 over
         | Ethernet (which comes with the pre-existing knowledge in
         | everyone, the years of experience working with it for any IT
         | person, the additional workarounds like NAT and UPnP and so on,
         | and even the oldest hardware still reasonably running having
         | full support) has made people think it was all just always easy
         | and obvious from the get-go. Where some of these protocol
         | assumptions and ingrained history didn't exist, like the mobile
         | carrier space, we see by far the most adoption of IPv6 out of
         | any area and even a few non-dual stack players.
         | 
         | The truth is like most topics in computing after 20 or 30 years
         | of using one protocol/interface the baggage, limitations, or
         | cost of the old keep piling up and eventually the new thing is
         | going to seem like less work/cost/baggage than the old.
         | 
         | The thing that seems to be moving it forward the most nowadays
         | is cost and baggage (= complexity = long way around to more
         | cost). The direct cost is per IPv4 prices going from ~$25/per
         | to ~$45/per in the last year alone. The baggage/complexity cost
         | is particularly on the carrier or large enterprise side where
         | ever growing device counts and ever growing public address
         | costs combine to make NAT needs larger and sometimes multi-
         | staged (e.g. CG-NAT).
         | 
         | I think the breaking point will be when we start to see most
         | hosting providers and carriers continue to either push
         | consumers to more IPv6 to reduce NAT load or cost incentivize
         | hosted services to do the same. There are limited instances of
         | this now, an occasional hosting provider offering IPv6 only for
         | a lower monthly cost or a mobile carrier that migrates all of
         | it's users to IPv6 transparently, but there are still more
         | providers/carriers that don't do anything IPv6 than there are
         | that incentivize IPv6. Definitely moving in that direction
         | these last few years though.
         | 
         | What I don't think we'll see is a sudden "aha" moment where
         | people give up IPv4 and stop being uncertain about v6 just
         | because they read about it more or were told some detail.
        
           | tolien wrote:
           | > I think the decades of dominance of UDP/TCP over IPv4 over
           | Ethernet (which comes with the pre-existing knowledge in
           | everyone, the years of experience working with it for any IT
           | person, the additional workarounds like NAT and UPnP and so
           | on, and even the oldest hardware still reasonably running
           | having full support) has made people think it was all just
           | always easy and obvious from the get-go.
           | 
           | Yeah, it doesn't feel like that long ago when consumer
           | routers with tiny translation tables would crash hard when
           | anything opened a load of connections (think games but
           | especially BitTorrent) because they didn't have much RAM.
           | 
           | I think for most people the switching moment will be
           | something they don't even see - their ISP enables it and off
           | they go.
        
       | coredog64 wrote:
       | If everyone moved to IPv6, Amazon couldn't charge AWS customers
       | for NAT gateways. Won't someone think of the $AMZN shareholders?
        
       | spc476 wrote:
       | I read all the time about how great the latest technology like
       | Docker and Kubernetes is, and how one should _always_ update
       | every 20 minutes or else you 'll have your entire _life,_ much
       | less your identity, stolen by hackers, and besides, who wants to
       | use software that 's an entire six months old? And yet, trying to
       | get anyone to upgrade to IPv6 and suddenly the entire world gets
       | super conservative and "hey now! Let's not get too hasty here!" I
       | can't quite square this circle.
        
       | EVa5I7bHFq9mnYK wrote:
       | I think ipv6 enables easier surveillance and censorship.
        
       | withinboredom wrote:
       | A personal bane of my existence is WSL's lack of ipv6 support.
       | You can't even use WireGuard and ipv6 because it's missing some
       | kernel options.
        
       | jrmg wrote:
       | I'm surprised at all the people here saying that they can't get
       | IPv6 to 'work' on their home internet connection. In my
       | experience, in the Bay Area, with Comcast cable and AT&T DSL
       | connections in the last few years (5 or 10), it's 'just worked'
       | for any device connected to the router they provide, no
       | configuration required.
       | 
       | I kind of assumed that this was true nowadays for most home ISPs.
        
         | deathanatos wrote:
         | I was in the Bay Area when Comcast ( _finally_ ) rolled it out;
         | it wasn't that long ago; it might have been >5 years now, but
         | definitely it was within the last 10.
         | 
         | Now I'm in the Boston MSA (a very rural place, I know /s); the
         | ISP here, Verizon, does not offer IPv6. (They state they are
         | "rolling it out", but this year will be the fifth anniversary
         | of that.)
        
       | buttocks wrote:
       | Speaking of Twitter, follow @noipv6 for some great commentary
       | and/or heckling of ISPs who make false claims about IPv6 to
       | defend their lack of support.
        
       | vardagsnytt wrote:
       | The perspective on this one is rather important I'd say. To run a
       | service and buying a few IPv4 addresses is quite feasible. But
       | operating an ISP and maintaining either large numbers of prefixes
       | or costly CGNAT hardware at that scale puts it way more into
       | focus.
       | 
       | Of course I'm not implying that IPv6 isn't nice to run inside
       | your infrastructure but I guess it isnt at the top of ones
       | expenses.
        
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