On 10/13/21 3:26 AM, Daniel Borkmann wrote:

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a control plane inserts the L3 (without L2) entries manually into the
neighbor table and lets the kernel do the neighbor resolution either
on the gateway or on the backend directly in case the latter resides
in the same L2. This avoids to deal with L2 in the control plane and
to rebuild what the kernel already does best anyway.

Are you using 'fib_multipath_use_neigh' sysctl to avoid going through
failed nexthops? Looking at how the bpf_fib_lookup() helper is
implemented, seems that you can benefit from it in XDP

Thanks for the pointer, we don't use it yet, but that's a great idea!

you should not have to do anything (beyond setting it if you have
control over that level).