Load balancer IP not accessible from external network

General Discussions
1

Hi Friends,

I installed kubernetes cluster 1.29.3 on RHEL8.9 with kubeadm installation method. I’m using metallb-system to provide external IP address to loadbalancer types.

Once traefik is installed - loadbalancer type service is getting created and external IP has been assigned from the Metallb IP Address Pool. We created one ingress, dns record created by external dns too. We are able to access same https URL within cluster, where as we are not able to access same URL from external cluster.

I tried two options

  1. cluster servers IP address vlan and external IP address vlan are same (Not working)
  2. cluster server IP address vlan and external IP address valn are different. (Not working either)

Cluster information:

Kubernetes version: 1.29.3
Cloud being used: bare-metal
Installation method: kubeadm
Host OS: RHEL8.9
CNI and version: flannel & 0.22.3
CRI and version: crio & 1.28.2

You can format your yaml by highlighting it and pressing Ctrl-Shift-C, it will make your output easier to read.

2

Thansks for your time. Issues is resolved now by creating L2Advertisement in metallb-system.

Metallb by default supports for all the services - it didn’t work in some of our clusters.

Metallb documentation note:
An empty L2Advertisement will enable MetalLB to advertise all the services belonging to all the pools via L2.

Adding one more leaning today ;
Below two cases are valid and works - as long as your loadbalancer IP can able to reach your cluster. Your cluster must be attached with service IP vlan in switch level to route traeffic to cluster if you are using a different vlan than cluster valn.

  1. cluster servers IP address vlan and external IP address vlan are same.
  2. cluster server IP address vlan and external IP address valn are different.

Thanks, Srinivasa