[ 1219.081464][T11111] Could not find device with ifindex 2000 in netnsfd 11
[ 1219.082201][T11111] Could not find netns with fd: 2000
[ 1219.082854][T11111] Cannot link a netdevsim to itself
[ 1219.083895][T11111] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).