SuSE firewall Issue

I’m having trouble configuring my SuSE firewall and was wondering if anyone has any experience to assist me or point me to some documentation that may help.

I have two multi-homed servers each with a public network interface on different subnets (e.g. and The servers are connected via an ipsec tunnel established using strongSwan VPN. I am able to ping these public ip addresses from the opposite server. Each server also has two private subnets. How can I configure the firewall so that I have connectivity from one server to a host on the opposite server’s private network?