Subj : Two ISPs and backup for a home network (dual-homing)
To   : Nil A
From : Victor Sudakov
Date : Tue Jun 29 2021 21:37:14

Dear Nil,

28 Jun 21 18:15, you wrote to me:

 VS>> What if I had two IPv6-capable ISPs for my home, and a /64 or a
 VS>> /56 from each of them? Is it possible to setup a backup link this
 VS>> way?
 NA> [...skip...]
 VS>> Can anyone enlighten me?

 NA> I don't see how iPv6 differs from IPv4 in this regard.

I'll clarify. In the case of IPv4, a LAN device has exactly one private IP address and one default route, the failover is done in the router, the devices are not aware of ISP failure.

In the case of IPv6, all LAN devices have at least two global addresses (from ISP1 block and from ISP2 block), so they must decide for themselves what outgoing address to choose.

 NA> Is it like you
 NA> have multiple A DNS records vs multiple AAAA records to point to your
 NA> node host name?

I did not say a word about DNS. I'm speaking about outgoing traffic on Layer 3.

Victor Sudakov, VAS4-RIPE, VAS47-RIPN
--- GoldED+/BSD 1.1.5-b20170303-b20170303
 * Origin: Ulthar (2:5005/49)

.