[ 1232.492887][T11127] Could not find device with ifindex 2000 in netnsfd 11
[ 1232.493572][T11127] Could not find netns with fd: 2000
[ 1232.494233][T11127] Cannot link a netdevsim to itself
[ 1232.495108][T11127] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).