Availability Groups – Add new subnet

All we need is an easy explanation of the problem, so here it is.

I have a two node Availability Group system which hosts several AvailabilityGroups. Each AG has it’s own listener.

The system was set up in an IP-subnet with very few free addresses left. How can i create new AvailabilityGroups in a new subnet?

Availability Groups - Add new subnet

How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

Method 1

I assume that you do not want to setup a multi-subnet clustering where each node is setup on a different subnet.

To be able to add a listener on a new subnet in the cluster the cluster computers need to be on that subnet sou you will need to add ip addresses on the new subnet to the existing network adapters on the servers (or install dedicated ones) and then you can add ip address on that subnet to the Availability Group. Then you will need to setup routing so other computers can connect to the listener or have the computers on that will connect to the listener on that subnet as well.

Depending on your network infrastructure and routing setup it might even be simpler to change the subnet mask to get more ip addresses. Going from 10.0.12.0/24 to 10.0.12.0/23 (mask: 255.255.254.0) would give you 256 more ip addresses to play with.

Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂

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