[ 1219.088203][T11129] Could not find device with ifindex 2000 in netnsfd 11
[ 1219.089049][T11129] Could not find netns with fd: 2000
[ 1219.089612][T11129] Cannot link a netdevsim to itself
[ 1219.090338][T11129] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).