[ 1236.606675][T10974] Could not find device with ifindex 2000 in netnsfd 11
[ 1236.607455][T10974] Could not find netns with fd: 2000
[ 1236.608093][T10974] Cannot link a netdevsim to itself
[ 1236.609056][T10974] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).