For HA, you need to use the FQDN instead of the IP address, and should be resolvable. Instead of making manual entries in the /etc/hosts file, you can use the DNS server to resolve them.
1. DNS entries:-
Master - 192.0.0.1/node1.example.com
Slave - 192.0.0.2/node2.example.com
Cluster address - cluster.example.com
When you install FAS you set the cluster address as something like cluster.example.com which resolves to both 192.168.0.1 & 192.168.0.2. Then requests to cluster.example.com can be routed to either node, each node will have an LB element and be able to route requests to the AS element on either node.
On the DNS server, entries should be like the following:-
Cluster address doesn't have its own IP, it will be resolved by both the master and slave IP's. Please make correct entries it's very important in a cluster environment.
2. Cluster Installation steps:-
On Master Node:-
You need to install FCSDK on the master node only by performing the below steps:
packs=COMMON,GATEWAY,CORE_SDK,SAMPLE_APP (Removing media broker because you will install it on saparate server)
On Slave Node:-
Only the FAS will be installed on the slave only by performing the below steps:
##Slave Node Configuration
Please refer article: https://cba-support.zendesk.com/hc/en-us/articles/360001010277-Install-and-Configure-Media-Broker for this.