[ 1221.621754][T11117] Could not find device with ifindex 2000 in netnsfd 11
[ 1221.622469][T11117] Could not find netns with fd: 2000
[ 1221.623071][T11117] Cannot link a netdevsim to itself
[ 1221.623776][T11117] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).