Session replication only functions for [Enterprise Licenses|Enterprise License Enhancements].  The servers participating in the replication must have a manual setting configuration done in their prefs.xml file.

Edit the prefs.xml file and fill in the entry for: replicate_session_host_port

Example for the first machine:

{{
    <replicate_session_host_port>192.168.1.19:7800</replicate_session_host_port>
}}

and on the second machine a reference back to the first machine.

{{
    <replicate_session_host_port>192.168.1.18:7800</replicate_session_host_port>
}}