IPAM Loadbalancer Is Ignoring Ipv6

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Introduction

In this article, we will explore the issue of IPAM load balancer ignoring IPv6 addresses. We will discuss the problem, its symptoms, and possible solutions. We will also provide a step-by-step guide on how to troubleshoot and resolve the issue.

Problem Description

The problem is that the IPAM load balancer is not announcing the IPv6 address of a service to the router. This is a critical issue, as it prevents the service from being accessible over IPv6.

Versions

The versions of the software used in this article are:

  • OSS V3.30
  • Openshift 4.18

Objects Created

The following objects were created to test the issue:

apiVersion: projectcalico.org/v3
kind: IPPool
metadata:
  name: loadbalancer-ip-pool-ipv4
spec:
  cidr: 192.210.0.0/24
  blockSize: 29
  natOutgoing: true
  disabled: false
  assignmentMode: Automatic
  allowedUses:
    - LoadBalancer

apiVersion: projectcalico.org/v3
kind: IPPool
metadata:
  name: loadbalancer-ip-pool-ipv6
spec:
  cidr: "fd00:10:0:0::/64"
  blockSize: 122
  natOutgoing: true
  disabled: false
  assignmentMode: Automatic
  allowedUses:
    - LoadBalancer

apiVersion: v1
kind: Service
metadata:
  name: apiserver-calico
  namespace: <namespace>
spec:
  externalTrafficPolicy: Local
  ports:
    - name: https
      port: 443
      protocol: TCP
      targetPort: 6443
  selector:
    apiserver: "true"
  type: LoadBalancer

Logs of Calico-Kube-Controllers

The logs of calico-kube-controllers show that the IPv4 address is being assigned to the service, but the IPv6 address is not being assigned.

2025-05-14 12:08:02.120 [INFO][12] kube-controllers/ipam.go 110: Auto-assign 1 ipv4, 0 ipv6 addrs for host 'load-balancer'
2025-05-14 12:08:02.124 [INFO][12] kube-controllers/ipam.go 691: Looking up existing affinities for host handle="lb-TAW6HjIEMHIu4cY6dgdQnXvfzVNpC2NYUX1pL2ivG3c" host="load-balancer"
2025-05-14 12:08:02.131 [INFO][12] kube-controllers/ipam.go 394: Looking up existing affinities for host host="load-balancer"
2025-05-14 12:08:02.144 [INFO][12] kube-controllers/ipam.go 511: Trying affinity for 192.210.0.80/29 virtual="load-balancer"
2025-05-14 12:08:02.147 [INFO][12] kube-controllers/ipam.go 158: Attempting to load block cidr=192.210.0.80/29 host="load-balancer"
2025-05-14 12:08:02.150 [INFO][12] kube-controllers/ipam.go 235: Affinity is confirmed and block has been loaded cidr=192.210.0.80/29 host="load-balancer"
2025-05-14 12:08:02.151 [INFO][12] kube-controllers/ipam.go 1220: Attempting to assign 1 addresses from block block=192.210.0.80/29 handle="lb-TAW6HjIEMHIu4cY6dgdQnXvfzVNpC2NYUX1pL2ivG3c" virtual="load-balancer"
2025-05-14 12:08:02.153 [INFO][12] kube-controllers/ipam.go 1764: Creating new handle: lb-TAW6HjIEMHIu4cY6dgdQnXvfzVNpC2NYUX1pL2ivG3c
2025-05-14 12:08:02.160 [INFO][12] kube-controllers/ipam.go 1243: Writing block in order to claim IPs block=192.210.0.80/29 handle="lb-TAW6HjIEMHIu4cY6dgdQnXvfzVNpC2NYUX1pL2ivG3c" virtual="load-balancer"
2025-05-14 12:08:02.168 [INFO][12] kube-controllers/ipam.go 1256: Successfully claimed IPs: [192.210.0.82/29] block=192.210.0.80/29 handle="lb-TAW6HjIEMHIu4cY6dgdQnXvfzVNpC2NYUX1pL2ivG3c" virtual="load-balancer"
2025-05-14 12:08:02.168 [INFO][12] kube-controllers/ipam.go 878: Auto-assigned 1 out of 1 IPv4s: [192.210.0.82/29] handle="lb-TAW6HjIEMHIu4cY6dgdQnXvfzVNpC2NYUX1pL2ivG3c" host="load-balancer"
2025-05-14 12:08:02.177 [INFO][12] kube-controllers/loadbalancer_controller.go 674: No new IPs to assign, Service already has desired LB addresses svc="apiserver-calico"
2025-05-14 12:08:02.184 [INFO][12] kube-controllers/loadbalancer_controller.go 674: No new IPs to assign, Service already has desired LB addresses svc="apiserver-calico"
2025-05-14 12:08:03.167 [INFO][12] kube-controllers/ipam.go 828: Checking dirty nodes for leaks and redundant affinities

Service Status

The service status shows that only the IPv4 address is being assigned.

apiVersion: v1
kind: Service
<snip>
status:
  loadBalancer:
    ingress:
    - ip: 192.210.0.82
      ipMode: VIP

Troubleshooting

To troubleshoot the issue, we need to check the following:

  1. IP Pool Configuration: Check if the IP pool configuration is correct. Make sure that the IPv6 pool is enabled and has the correct CIDR range.
  2. Service Configuration: Check if the service configuration is correct. Make sure that the service type is set to LoadBalancer and that the externalTrafficPolicy is set to Local.
  3. Calico-Kube-Controllers Logs: Check the calico-kube-controllers logs to see if there are any errors or warnings related to the IPv6 address assignment.
  4. IPAM Configuration: Check the IPAM configuration to see if it is correctly configured to assign IPv6 addresses.

Solution

To solve the issue, we need to:

  1. Enable IPv6 Pool: Enable the IPv6 pool by setting the disabled field to false in the IP pool configuration.
  2. Set IPv6 Pool Annotation: Set the projectcalico.org/ipv6pools annotation to the name of the IPv6 pool.
  3. Check IPAM Configuration: Check the IPAM configuration to see if it is correctly configured to assign IPv6 addresses.

Conclusion

In this article, we explored the issue of IPAM load balancer ignoring IPv6 addresses. We discussed the problem, its symptoms, and possible solutions. We also provided a step-by-step guide on how to troubleshoot and resolve the issue. By following the steps outlined in this article, you should be able to resolve the issue and get your IPv6 addresses assigned correctly.

Additional Resources

Introduction

In our previous article, we explored the issue of IPAM load balancer ignoring IPv6 addresses. We discussed the problem, its symptoms, and possible solutions. In this article, we will provide a Q&A section to help you better understand the issue and its resolution.

Q: What is the cause of the IPAM load balancer ignoring IPv6 addresses?

A: The cause of the IPAM load balancer ignoring IPv6 addresses is due to a misconfiguration of the IP pool or the service. The IP pool configuration may not be correctly set up to assign IPv6 addresses, or the service configuration may not be set up to use IPv6 addresses.

Q: How do I check if the IP pool configuration is correct?

A: To check if the IP pool configuration is correct, you can check the following:

  • Make sure that the IPv6 pool is enabled and has the correct CIDR range.
  • Check the disabled field in the IP pool configuration to ensure that it is set to false.
  • Check the allowedUses field in the IP pool configuration to ensure that it includes LoadBalancer.

Q: How do I check if the service configuration is correct?

A: To check if the service configuration is correct, you can check the following:

  • Make sure that the service type is set to LoadBalancer.
  • Check the externalTrafficPolicy field in the service configuration to ensure that it is set to Local.
  • Check the ports field in the service configuration to ensure that it includes the correct port for the service.

Q: What is the projectcalico.org/ipv6pools annotation?

A: The projectcalico.org/ipv6pools annotation is used to specify the name of the IPv6 pool that should be used for the service. This annotation should be set on the service object to ensure that the correct IPv6 pool is used.

Q: How do I set the projectcalico.org/ipv6pools annotation?

A: To set the projectcalico.org/ipv6pools annotation, you can add the following line to the service object:

annotations:
  projectcalico.org/ipv6pools: '["loadbalancer-ip-pool-ipv6"]'

Replace loadbalancer-ip-pool-ipv6 with the name of the IPv6 pool that you want to use.

Q: What are the possible solutions to the issue?

A: The possible solutions to the issue are:

  • Enable the IPv6 pool by setting the disabled field to false in the IP pool configuration.
  • Set the projectcalico.org/ipv6pools annotation to the name of the IPv6 pool.
  • Check the IPAM configuration to ensure that it is correctly configured to assign IPv6 addresses.

Q: How do I troubleshoot the issue?

A: To troubleshoot the issue, you can check the following:

  • Check the calico-kube-controllers logs to see if there are any errors or warnings related to the IPv6 address assignment.
  • Check the IPAM configuration to ensure that it is correctly configured to assign IPv6 addresses.
  • Check the service configuration to ensure that it is correctly set up to use IPv6 addresses.

Q: What are the best practices for configuring IPAM and load balancers?

A: The best practices for configuring IPAM and load balancers are:

  • Ensure that the IP pool configuration is correctly set up to assign IPv6 addresses.
  • Ensure that the service configuration is correctly set up to use IPv6 addresses.
  • Use the projectcalico.org/ipv6pools annotation to specify the name of the IPv6 pool that should be used for the service.
  • Check the IPAM configuration to ensure that it is correctly configured to assign IPv6 addresses.

Conclusion

In this Q&A article, we provided answers to common questions related to the issue of IPAM load balancer ignoring IPv6 addresses. We hope that this article has helped you better understand the issue and its resolution. If you have any further questions, please don't hesitate to ask.