Port-forwarding to resource on Kubernetes cluster running in Virtualbox not working with TL-R605

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Port-forwarding to resource on Kubernetes cluster running in Virtualbox not working with TL-R605

This thread has been locked for further replies. You can start a new thread to share your ideas or ask questions.
Port-forwarding to resource on Kubernetes cluster running in Virtualbox not working with TL-R605
Port-forwarding to resource on Kubernetes cluster running in Virtualbox not working with TL-R605
2022-10-19 08:58:09 - last edited 2022-10-19 11:28:09
Tags: #NAT
Model: ER605 (TL-R605)  
Hardware Version: V1
Firmware Version: 1.2.1

In my network I am running a Kubernetes cluster in Virtualbox for development purposes. One of the applications requires TLS certificates, which I try to receive with cert-manager. For that I need to open port 80 to the outside world and created port-forwarding rules. However, whatever I try to do I cannot seem to get through the ER605.

 

My setup is as follows:

1. Nginx pod is running on Kuberenetes with port 80 available

2. Kubernetes is running in VMs on Virtualbox with bridged NICs

3. Virtualbox is running on a server with Ubunutu and is in the same subnet as the VMs

4. There are 2 switches between the server and the gateway (TL-SG2008P)

4. The gateway that is used is the ER605 and is in the same subnet ast the server/VMs

5. The gateway is connected to a router (to separate the network from other business in the same building)

6. The router is connected to the internet

 

I have full access to all devices in the network, including the router as I maintain the connection for the entire building.

On the internal network I can reach the service running in Kubernetes without any issues. But from the outside world i cannot get connected. So what I tried, was to see if I could reach the service from the network between the router and the gateway. This didn't work either. I tried to change ports and changed it to port 8089 without a positive result. I also tried to run a container directly on the server in Podman on port 80 without any issue. Then I created a new VM in Virtualbox with a webserver running on port 80. Since I changed the pod back to port 8089. I added the a new rule that points to the new VM. When I tried to reach that server, I suddenly got access to the pod that is running on another port. So I decided to reboot the gateway to see if everything started to work properly. That resulted in a properly working port 80, which was still pointing to the VM. But on port 8089, couldn't reach the pod anymore.

 

As you might understand, this left me confused. I don't get what is going on and I don't know how to solve this.

Is there an issue with the ER605 that it cannot handle the combination of Virtualbox and Kubernetes regarding port-forwarding? Have I overlooked something? And does anyone have an idea how to get this solved?

 

Thank you in advance for your time!

 

Edit: It is probably also good to know that I am using OpenELB as a load balancer in Kubernetes to assign an external ip address to the services in Kubernetes.

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Re:Port-forwarding to resource on Kubernetes cluster running in Virtualbox not working with TL-R605
2022-10-20 11:08:48

  @ArjanH 

 

Have you tried DMZ?

Suggest you can open DMA for testing.

Just striving to develop myself while helping others.
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Re:Port-forwarding to resource on Kubernetes cluster running in Virtualbox not working with TL-R605
2022-10-20 17:51:01

  @Virgo 

 

Thank you for taking the time to reply.

 

Yes, but that breaks other port forwarding rules and the VPN connection. Besides that it is not really safe either. 

But I don't understand why I don't have an issue forwarding something to a virtual machine or a container on a physical server. But when kubernetes comes in it fails...

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