[ 1235.114535][T10976] Could not find device with ifindex 2000 in netnsfd 11
[ 1235.115334][T10976] Could not find netns with fd: 2000
[ 1235.115998][T10976] Cannot link a netdevsim to itself
[ 1235.124047][T10976] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).