the solution to this issue as worked up in our private chat is - for the rest of the world:

Hi @c-po and thanks for the insight. I understand that this is a workaround for a reboot safe configuration if you're using vrf bgp neighbors.
We are also using vrf inside our infrastructure as well without vrf bgp neighbors and only redistribute connected routes and advertise them via EVPN.

https://github.com/vyos/vyos-1x/pull/4677

In T7665#230894, @fernando wrote:

patch : https://github.com/FRRouting/frr/pull/16159/commits/f153b9a9b636e7ca16ef066e934d355ba922df2b

@dmbaturin, @c-po, @jestabro and @n.fort

This appears to be a logical bug. I have opened a Pull Request to fix it.
https://github.com/vyos/vyos-1x/pull/4663

PR:
https://github.com/vyos/vyos-1x/pull/4657

https://github.com/vyos/vyos-1x/pull/4656

The issue is also present in Stream Q2 image and rolling.

My €0.05 in this topic is if the "ipv6 address autoconf" should instead be named "ipv6 address slaac" since after all the feature is named "stateless address autoconfiguration" aka slaac and not necessary "autoconf". But I think its a matter of taste if it should be called "autconf" or "slaac".

@c-po if I understand you correctly, for 1.4.4, you are going to make a migration file that looks for interfaces that have only:

@ryanzuwala I think of a change in 1.4.4 which requires config migration. So if one has a working config in 1.4.2 that is "invalid" as it lacks the "ipv6 address autoconf" node - the migrator will add it to restore previous behavior AND have all CLI nodes in place to be a good internet citizen.

Re-opened for 1.4.4 backport

In T7646#231848, @ryanzuwala wrote:

@josha I agree with you. Perhaps it should be like this?

• ipv6 address autoconf - accept RAs and do whatever M and O flags tell it to do
• ipv6 address dhcpv6 - DCHPv6 without RAs, determine default route from neighbor discovery (possibly using the functionality in @josha script above)
• ipv6 address dhcpv6 no-default-gateway - DHCPv6 without RAs, must configure default route separately if needed
• ipv6 address xx:xx:xx.... - Static IP

For the latest rolling seems fixed in T6371

vyos@r14# run show nat source rules 
Rule    Source          Destination        Proto    Out-Int    Translation
------  --------------  -----------------  -------  ---------  -------------
230     192.168.0.0/16  192.168.0.5        UDP      eth1       masquerade
        sport any       dport 60000-60010
[edit]
vyos@r14#

@josha I agree with you. Perhaps it should be like this?

In T7646#231844, @ryanzuwala wrote:

Based on a recent Slack conversation we had about this, it seems like the most reasonable solution is to have configuration options like this:

• ipv6 address autoconf - accept RAs and do whatever M and O flags tell it to do
• ipv6 address dhcpv6 - DHCPv6 without RAs, must configure default route separately if needed
• ipv6 address dhcpv6 nd-defgtw - DCHPv6 without RAs, determine default route from neighbor discovery (possibly using the functionality in @josha script above)
• ipv6 address xx:xx:xx.... - Static IP

Based on a recent Slack conversation we had about this, it seems like the most reasonable solution is to have configuration options like this:

There are more fundamental problems here with the implementation that are incomplete.

https://github.com/vyos/vyos-1x/pull/4634