Subj : Two ISPs and backup for a home network (dual-homing)
To   : Dmitry Protasoff
From : Victor Sudakov
Date : Tue Jun 29 2021 21:46:30

Dear Dmitry,

29 Jun 21 00:08, 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?

 DP> Sure.

I'm not so sure already.

 VS>> I know that my home router can advertise multiple global IPv6
 VS>> prefixes into the LAN, but how will LAN hosts failover to the
 VS>> backup gateway if the primary ISP fails? They will have IPv6
 VS>> addresses from both blocks, which should they choose for their
 VS>> outgoing src address?

 DP> NPTv6 is the answer (RFC 6296).

It's not a good answer. One of the key priorities of IPv6 as touted by its proponents is the end-to-end connectivity, freedom from NAT.

 DP> Not sure if your router can handle it.

Do not want :-)

Victor Sudakov, VAS4-RIPE, VAS47-RIPN
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 * Origin: Ulthar (2:5005/49)

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