[ 1121.071019][T11116] Could not find device with ifindex 2000 in netnsfd 11
[ 1121.071737][T11116] Could not find netns with fd: 2000
[ 1121.072274][T11116] Cannot link a netdevsim to itself
[ 1121.072991][T11116] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).