By default, as part of the Interset 4.1 installation, you will disable the iptables firewall. If this is not possible, firewall exceptions can be created which will allow all required traffic for the product to function as expected.
The attached scripts can be used to achieve this, and are labelled according to server role as outlined in the Installation and Configuration Guide.
At the top of each of these scripts are two or three variables referencing the other nodes in the environment. These should be updated to specify the IP address of the associated nodes, for example: