[ 1219.241563][T11123] Could not find device with ifindex 2000 in netnsfd 11
[ 1219.242338][T11123] Could not find netns with fd: 2000
[ 1219.242948][T11123] Cannot link a netdevsim to itself
[ 1219.243960][T11123] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).