kubernetes/kops · error

NLB has more then one AllocationID per subnet, which is unex

Error message

NLB has more then one AllocationID per subnet, which is unexpected. This is a bug in kOps, please open a GitHub issue.

What it means

While importing an existing NLB into the kOps model, a single subnet mapping carried two AllocationIds (or two PrivateIPv4Addresses) — AWS state the SubnetMapping model cannot represent; this is treated as a kOps bug, not a user configuration error.

Source

Thrown at upup/pkg/fi/cloudup/awstasks/network_load_balancer.go:238

			continue
		}
		actual.Tags[k] = aws.ToString(tag.Value)
	}

	for _, az := range lb.AvailabilityZones {
		sm := &SubnetMapping{
			Subnet: &Subnet{ID: az.SubnetId},
		}
		for _, a := range az.LoadBalancerAddresses {
			if a.PrivateIPv4Address != nil {
				if sm.PrivateIPv4Address != nil {
					return nil, fmt.Errorf("NLB has more then one PrivateIPv4Address, which is unexpected. This is a bug in kOps, please open a GitHub issue.")
				}
				sm.PrivateIPv4Address = a.PrivateIPv4Address
			}
			if a.AllocationId != nil {
				if sm.AllocationID != nil {
					return nil, fmt.Errorf("NLB has more then one AllocationID per subnet, which is unexpected. This is a bug in kOps, please open a GitHub issue.")
				}
				sm.AllocationID = a.AllocationId
			}
		}
		actual.SubnetMappings = append(actual.SubnetMappings, sm)
	}

	for _, sg := range lb.SecurityGroups {
		actual.SecurityGroups = append(actual.SecurityGroups, &SecurityGroup{ID: aws.String(sg)})
	}

	{
		lbAttributes, err := findNetworkLoadBalancerAttributes(ctx, cloud, loadBalancerArn)
		if err != nil {
			return nil, err
		}
		klog.V(4).Infof("NLB Load Balancer attributes: %+v", lbAttributes)

View on GitHub (pinned to 4c8573c808)

Solutions

1. Inspect the NLB's subnet mappings in the AWS console for duplicated addresses and normalize them
2. Open a GitHub issue at kOps with the NLB details so the import path can handle this state

When it happens

Trigger: Thrown at upup/pkg/fi/cloudup/awstasks/network_load_balancer.go:238 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/3469d7238d2a1846. Report an issue: GitHub.