On Sun, Dec 21, 2025 at 07:26:38PM +0000, Vadim Fedorenko wrote:

Preference of nexthop with source address broke ECMP for packets with
source addresses which are not in the broadcast domain, but rather added
to loopback/dummy interfaces. Original behaviour was to balance over
nexthops while now it uses the latest nexthop from the group. To fix the
issue introduce next hop scoring system where next hops with source
address equal to requested will always have higher priority.

[...]

Fixes: 32607a332cfe ("ipv4: prefer multipath nexthop that matches source address")
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>

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