[  986.423426][ T8116] Could not find device with ifindex 2000 in netnsfd 11
[  986.424153][ T8116] Could not find netns with fd: 2000
[  986.424696][ T8116] Cannot link a netdevsim to itself
[  986.425367][ T8116] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).