[ 1083.304379][T10969] Could not find device with ifindex 2000 in netnsfd 11
[ 1083.305096][T10969] Could not find netns with fd: 2000
[ 1083.305623][T10969] Cannot link a netdevsim to itself
[ 1083.306311][T10969] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).