[  393.082557][ T5177] Could not find device with ifindex 2000 in netnsfd 11
[  393.083232][ T5177] Could not find netns with fd: 2000
[  393.083780][ T5177] Cannot link a netdevsim to itself
[  393.084448][ T5177] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).