[ 1221.845433][T11128] Could not find device with ifindex 2000 in netnsfd 11
[ 1221.846076][T11128] Could not find netns with fd: 2000
[ 1221.846594][T11128] Cannot link a netdevsim to itself
[ 1221.847447][T11128] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).