[ 1231.494767][T11118] Could not find device with ifindex 2000 in netnsfd 11
[ 1231.495594][T11118] Could not find netns with fd: 2000
[ 1231.496244][T11118] Cannot link a netdevsim to itself
[ 1231.497009][T11118] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).