{"record":{"id":"628326a23f7a324b","repo":"XTLS/Xray-core","slug":"default-route-interface-is-not-usable","errorCode":null,"errorMessage":"default route interface is not usable","messagePattern":"default route interface is not usable","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"proxy/tun/tun_darwin.go","lineNumber":561,"sourceCode":"\tcase *route.Inet6Addr:\n\t\tmask, ok := message.Addrs[unix.RTAX_NETMASK].(*route.Inet6Addr)\n\t\tif !ok || destination.IP != netip.IPv6Unspecified().As16() {\n\t\t\treturn 0, false\n\t\t}\n\t\tones, bits := net.IPMask(mask.IP[:]).Size()\n\t\treturn unix.AF_INET6, ones == 0 && bits == 128\n\tdefault:\n\t\treturn 0, false\n\t}\n}\n\nfunc usableDarwinInterface(index int) (*net.Interface, error) {\n\tiface, err := net.InterfaceByIndex(index)\n\tif err != nil {\n\t\treturn nil, err\n\t}\n\tif iface.Flags&net.FlagUp == 0 || iface.Flags&net.FlagLoopback != 0 {\n\t\treturn nil, errors.New(\"default route interface is not usable\")\n\t}\n\treturn iface, nil\n}\n\nfunc (t *DarwinTun) setSystemRoutes() error {\n\troutes, err := buildDarwinSystemRoutes(t.options.AutoSystemRoutingTable)\n\tif err != nil {\n\t\treturn err\n\t}\n\tif len(routes) == 0 {\n\t\treturn nil\n\t}\n\n\ttunIndex, err := t.Index()\n\tif err != nil {\n\t\treturn err\n\t}\n\tfor _, destination := range routes {","sourceCodeStart":543,"sourceCodeEnd":579,"githubUrl":"https://github.com/XTLS/Xray-core/blob/7d214f8b094f75322fa3990f8aadad1c912f24f5/proxy/tun/tun_darwin.go#L543-L579","documentation":"Error \"default route interface is not usable\" thrown in XTLS/Xray-core.","triggerScenarios":"Thrown at proxy/tun/tun_darwin.go:561 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"7d214f8b094f75322fa3990f8aadad1c912f24f5","analyzedAt":"2026-08-15T14:26:24.325Z","schemaVersion":2},"datasetVersion":"2026-08-15T17:31:12.345Z"}