[  998.728502][ T7976] Could not find device with ifindex 2000 in netnsfd 11
[  998.729228][ T7976] Could not find netns with fd: 2000
[  998.729838][ T7976] Cannot link a netdevsim to itself
[  998.730585][ T7976] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).