FireWall-1 FAQ: What Should My Encryption Domain Be?
Please note: This content was from when I was operating my FireWall-1 FAQ site, which I stopped operating in August 2005. For some reason people still have links to this stuff on the Internet that people are still clicking on.
I am making this information available again AS IS. Given how old this information is, it is likely wildly inaccurate. I have no plans to update this information.
If you're still running versions of Check Point VPN-1/FireWall-1 where this information is still relevant to you, do yourself a favor and upgrade to a more recent release. If you happen to be running a current release and the information is useful, it's by happenstance :)
You encryption domain (usually) should include all networks behind your firewall. If you are performing any Network Address Translation, you should also include any translated addresses in your encryption domain as well. Note that I usually define it as a group called "firewall-encdomain" where firewall is the name of your firewall object.