VRRPv3 RFC9568 checksum compliance breaks interop with Cumulus (FRR too old)

[jbemmel]

This breaks interop for Cumulus with image CumulusCommunity/cumulus-vx:4.4.5, it has FRR 7.5 which does not support this option

Not even the latest Cumulus image CumulusCommunity/cumulus-vx:5.9.2 contains a new enough FRR binary

We could:

• add a quirk saying Cumulus/Cumuls NVUE don't support VRRPv4

• make the RFC 9568 compliance configurable (default True)

Originally posted by @jbemmel in cb2359c

[ipspace]

Not even the latest Cumulus image CumulusCommunity/cumulus-vx:5.9.2 contains a new enough FRR binary

🤷‍♂️ There are tons of suboptimal implementations in the wild ;) Also:

• We don't know whether any other platform does checks in the same way EOS does, and I will not waste my time doing a full cross-platform matrix test.
• The only platforms failing the tests are FRR-based.
• The only way to experience the problem is if you have different devices in the same VRRP group which is somewhat unlikely in real-world scenarios

• add a quirk saying Cumulus/Cumuls NVUE don't support VRRPv4

There is no VRRPv4. All you can say is that Cumulus (and VyOS) do not yet implement RFC 9568, and I don't think this deserves more than a mention in the caveats.

• make the RFC 9568 compliance configurable (default True)

Not going to happen.

[jbemmel]

I meant "VRRPv3 for ipv4" but I'm ok with the warning level in the tests, and you're correct that in typical deployments they'd interop with themselves and there is no issue