[ 1249.951790][T11129] Could not find device with ifindex 2000 in netnsfd 11
[ 1249.952616][T11129] Could not find netns with fd: 2000
[ 1249.953566][T11129] Cannot link a netdevsim to itself
[ 1249.954303][T11129] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).