[ 1234.135510][T11129] Could not find device with ifindex 2000 in netnsfd 11
[ 1234.136237][T11129] Could not find netns with fd: 2000
[ 1234.136849][T11129] Cannot link a netdevsim to itself
[ 1234.137532][T11129] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).