[ 949.176475][ T8109] Could not find device with ifindex 2000 in netnsfd 11 [ 949.177139][ T8109] Could not find netns with fd: 2000 [ 949.177661][ T8109] Cannot link a netdevsim to itself [ 949.178311][ T8109] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).