Specify the interface through which packets should be transmitted so that the test will pass regardless of the libnet version against which mausezahn is linked. Fixes:cab14d1087("selftests: Add version of router_multipath.sh using nexthop objects") Fixes:3d578d8795("selftests: forwarding: Test IPv4 weighted nexthops") Signed-off-by: Danielle Ratson <danieller@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>