[ 1222.421772][T11132] Could not find device with ifindex 2000 in netnsfd 11
[ 1222.422499][T11132] Could not find netns with fd: 2000
[ 1222.423070][T11132] Cannot link a netdevsim to itself
[ 1222.423748][T11132] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).