[ 1213.684072][T11108] Could not find device with ifindex 2000 in netnsfd 11
[ 1213.684824][T11108] Could not find netns with fd: 2000
[ 1213.685428][T11108] Cannot link a netdevsim to itself
[ 1213.686362][T11108] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).