[ 1214.702218][T11126] Could not find device with ifindex 2000 in netnsfd 11
[ 1214.702974][T11126] Could not find netns with fd: 2000
[ 1214.703570][T11126] Cannot link a netdevsim to itself
[ 1214.704303][T11126] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).