[ 1221.898858][T11115] Could not find device with ifindex 2000 in netnsfd 11
[ 1221.899582][T11115] Could not find netns with fd: 2000
[ 1221.905547][T11115] Cannot link a netdevsim to itself
[ 1221.906272][T11115] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).