[ 1220.928677][T11128] Could not find device with ifindex 2000 in netnsfd 11
[ 1220.929381][T11128] Could not find netns with fd: 2000
[ 1220.929978][T11128] Cannot link a netdevsim to itself
[ 1220.930934][T11128] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).