[ 1087.086328][T11263] Could not find device with ifindex 2000 in netnsfd 11
[ 1087.087032][T11263] Could not find netns with fd: 2000
[ 1087.087564][T11263] Cannot link a netdevsim to itself
[ 1087.088201][T11263] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).