[ 1216.306215][T11124] Could not find device with ifindex 2000 in netnsfd 11
[ 1216.306899][T11124] Could not find netns with fd: 2000
[ 1216.307445][T11124] Cannot link a netdevsim to itself
[ 1216.308089][T11124] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).