[ 1101.187940][T11270] Could not find device with ifindex 2000 in netnsfd 11
[ 1101.188714][T11270] Could not find netns with fd: 2000
[ 1101.189285][T11270] Cannot link a netdevsim to itself
[ 1101.190028][T11270] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).