[ 1123.468454][T11296] Could not find device with ifindex 2000 in netnsfd 11
[ 1123.469149][T11296] Could not find netns with fd: 2000
[ 1123.469667][T11296] Cannot link a netdevsim to itself
[ 1123.470372][T11296] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).