Multus CNI using Ipvlan plug-in for multiple networks in OpenShift

In this article, I will show you how to configure the multiple networks in OpenShift using the Multus CNI based on ipvlan plug-in with other optional CNI plug-ins. Personally, I think the ipvlan CNI plug-in is the most useful and easy in most cases and environments due to less restrictions to use, I hope this demonstration to help your implementations. If you need more information about CNI, then it’s helpful to refer Using the Multus CNI in OpenShift I wrote first before reading this post.

Demonstration summary

I will demonstrate to add two ipvlan interface for a test pod, and test to connect each external network configured different networks. The above figure describes this in details. All tests has been conducted on OpenShift Container Platform v4.6.

Configuration procedures

Add two additional networks that have a routing rules on each of that through the Cluster Network Operator(CNO) CustomResource(CR) as follows. You also should configure 192.168.12.1 GW can route each of external 192.168.8.0/24 and 192.168.9.0/24 network appropriately in advance before this testing.

Create a test pod with the two networks as follows.

Connectability test

Verify the added network interfaces on the scheduled node host using SSH or “oc debug node/NODENAME”.

Configured routing rule test as follows. You should prepare your testing web server in each external network. In my case, the web server IP is each of 192.168.8.10 and 192.168.9.10. It shows us 192.168.12.80 → 192.168.8.10 and 192.168.12.90 → 192.168.9.10 are available.

Yeah, all connection was successful to access to each web server on different networks.

Thank you for reading.