{"record":{"id":"0207a751c81bb3a9","repo":"kubernetes/kops","slug":"multiple-ipv6-addresses-found-on-interface-q-v","errorCode":null,"errorMessage":"multiple ipv6 addresses found on interface %q: %v","messagePattern":"multiple ipv6 addresses found on interface %q: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"cmd/kops-controller/controllers/gceipam.go","lineNumber":135,"sourceCode":"\t\tif err != nil {\n\t\t\treturn ctrl.Result{}, fmt.Errorf(\"getting instance %s/%s/%s: %w\", project, zone, instanceID, err)\n\t\t}\n\n\t\tvar ipv6Addresses []string\n\t\tfor _, nic := range instance.NetworkInterfaces {\n\t\t\tfor _, ipv6AccessConfig := range nic.Ipv6AccessConfigs {\n\t\t\t\tif ipv6AccessConfig.ExternalIpv6 != \"\" {\n\t\t\t\t\tipv6Address := fmt.Sprintf(\"%s/%d\", ipv6AccessConfig.ExternalIpv6, ipv6AccessConfig.ExternalIpv6PrefixLength)\n\t\t\t\t\tipv6Addresses = append(ipv6Addresses, ipv6Address)\n\t\t\t\t}\n\t\t\t}\n\t\t}\n\n\t\tif len(ipv6Addresses) == 0 {\n\t\t\treturn ctrl.Result{}, fmt.Errorf(\"no ipv6 address found on interface %q\", instance.NetworkInterfaces[0].Name)\n\t\t}\n\t\tif len(ipv6Addresses) != 1 {\n\t\t\treturn ctrl.Result{}, fmt.Errorf(\"multiple ipv6 addresses found on interface %q: %v\", instance.NetworkInterfaces[0].Name, ipv6Addresses)\n\t\t}\n\n\t\tipv6Address := ipv6Addresses[0]\n\t\tpodCIDRs := []string{ipv6Address}\n\t\tif err := patchNodePodCIDRs(r.coreV1Client, ctx, node, podCIDRs); err != nil {\n\t\t\treturn ctrl.Result{}, err\n\t\t}\n\t}\n\n\treturn ctrl.Result{}, nil\n}\n\nfunc (r *GCEIPAMReconciler) SetupWithManager(mgr ctrl.Manager) error {\n\treturn ctrl.NewControllerManagedBy(mgr).\n\t\tNamed(\"gce_ipam\").\n\t\tFor(&corev1.Node{}).\n\t\tComplete(r)\n}","sourceCodeStart":117,"sourceCodeEnd":153,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/cmd/kops-controller/controllers/gceipam.go#L117-L153","documentation":"The GCE IPAM reconciler found more than one external IPv6 address across the instance's network interfaces and cannot decide which to use. GCE IPAM expects exactly one IPv6 access config per instance.","triggerScenarios":"Thrown at cmd/kops-controller/controllers/gceipam.go:135 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":["Inspect the instance's network interfaces and remove the extra IPv6 access config","Fix the instance template so only one interface gets an external IPv6 address"],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T07:17:12.445Z"}