[ 1238.341319][T10971] Could not find device with ifindex 2000 in netnsfd 11
[ 1238.342352][T10971] Could not find netns with fd: 2000
[ 1238.343212][T10971] Cannot link a netdevsim to itself
[ 1238.344278][T10971] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).