Re: [PATCH iproute2-next v2 2/2] ip nexthop: support fdb destination port

On Thu, Jul 23, 2026 at 01:25:08AM +0000, Jack Ma wrote:

The kernel gained NHA_DST_PORT, an optional per-nexthop UDP destination
port for fdb nexthops.  VXLAN uses it to reach several receivers that
share an underlay IP but listen on different ports, load-balancing a
flow across (IP, port) legs of one nexthop group.

Wire it into `ip nexthop`:

  ip nexthop add id 1 via 192.0.2.1 fdb dst_port 4790

The port is parsed on add (sent as NHA_DST_PORT, __be16, network order)
and printed back on dump/get.  The kernel only accepts it together with
fdb and a gateway.

Signed-off-by: Jack Ma <redacted>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>