[ 1296.459529][T11447] Could not find device with ifindex 2000 in netnsfd 11
[ 1296.460536][T11447] Could not find netns with fd: 2000
[ 1296.461303][T11447] Cannot link a netdevsim to itself
[ 1296.462067][T11447] Format for linking two devices is "netnsfd_a:ifidx_a netnsfd_b:ifidx_b" (int uint int uint).