[ 1086.465907][T10968] Could not find device with ifindex 2000 in netnsfd 11 [ 1086.466950][T10968] Could not find netns with fd: 2000 [ 1086.467825][T10968] Cannot link a netdevsim to itself [ 1086.468915][T10968] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).