Unicast Clustering

Expand the Environment node and click on clusters
Click New to create a new Cluster.

Enter the name for cluster
Select messaging mode as Unicast
Enter a name for Unicast Broadcast Channel and click OK

Click on the UnicastCluster

Click on servers and click Add to add the managed servers to cluster.

Select the managed server that you want to add to the cluster and click finish.
Similarly add the second server too.

Now you have to create a network channel.

Click on servers and click the managed server.

Click on protocols and click channels
Click on New to create a channel

Enter the channel name that you have given during the creation of cluster.
Select cluster-broadcast for protocol and click Next.

Enter the listen address and click ok to create the channel.
Create the channel with same name for second managed server.

That's it you're done...