[  243.024951][ T3591] Could not find device with ifindex 2000 in netnsfd 11
[  243.025698][ T3591] Could not find netns with fd: 2000
[  243.026283][ T3591] Cannot link a netdevsim to itself
[  243.027255][ T3591] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).