[ 1219.893540][T11119] Could not find device with ifindex 2000 in netnsfd 11
[ 1219.900877][T11119] Could not find netns with fd: 2000
[ 1219.901532][T11119] Cannot link a netdevsim to itself
[ 1219.902298][T11119] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).