[ 1221.616629][T11118] Could not find device with ifindex 2000 in netnsfd 11
[ 1221.617978][T11118] Could not find netns with fd: 2000
[ 1221.618922][T11118] Cannot link a netdevsim to itself
[ 1221.620389][T11118] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).