[ 466.752167] Could not find device with ifindex 2000 in netnsfd 11 [ 466.752323] Could not find netns with fd: 2000 [ 466.752407] Cannot link a netdevsim to itself [ 466.752561] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).