[ 1221.951811][T11131] Could not find device with ifindex 2000 in netnsfd 11
[ 1221.952530][T11131] Could not find netns with fd: 2000
[ 1221.953072][T11131] Cannot link a netdevsim to itself
[ 1221.953776][T11131] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).