Re: [PATCH net v5 1/2] vxlan: reject adding a remote to a nexthop fdb entry

[Ido Schimmel]

Thank you for giving me two minutes to reply before posting a new
version [1][2].

[1] https://lore.kernel.org/netdev/CAEnQdOoQRuH8A=HnJqruN_kp5exzTwV7bK-LZUVo=LGuSMmgNA@xxxxxxxxxxxxxx/
[2] https://lore.kernel.org/netdev/20261027104713.328028-1-bsdhenrymartin@xxxxxxxxx/

On Wed, Oct 28, 2026 at 07:16:25PM +0800, Henry Martin wrote:
> FDB entries backed by a nexthop group must not carry a remote
> destination list.  vxlan_fdb_update_existing() currently appends a
> remote via vxlan_fdb_append() on an NLM_F_APPEND request with a
> multicast or zero MAC even when the entry is backed by a nexthop,
> breaking that invariant through three different callers:

BUM traffic should always be flooded. It makes no sense to load balance
it between different VTEPs. Simply forbid the creation of a multicast /
all-zeroes FDB that points to an FDB nexthop in
vxlan_fdb_update_create(). This is net-next material.