[ 1231.684545][T11122] Could not find device with ifindex 2000 in netnsfd 11
[ 1231.685418][T11122] Could not find netns with fd: 2000
[ 1231.686075][T11122] Cannot link a netdevsim to itself
[ 1231.687091][T11122] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).