[ 1233.548110][T11123] Could not find device with ifindex 2000 in netnsfd 11
[ 1233.548898][T11123] Could not find netns with fd: 2000
[ 1233.549511][T11123] Cannot link a netdevsim to itself
[ 1233.550292][T11123] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).