Operate SunScreen EFS 3.0 in routing mode if you need routing functions in addition to firewall capabilities. In this mode, SunScreen EFS 3.0 operates as both a router and a firewall, with at least two exposed IP interfaces, and a hop visible to traceroute and other network utilities. Be aware that your firewall is visible when operating in routing mode, and you have a slightly greater exposure to attack than when operating in stealth mode.
Key differences when operating SunScreen EFS 3.0 in routing, rather than stealth, mode:
The existing Solaris machine must be acting as a router.
It makes use of the Solaris IP stack on the filtering interfaces, so it does not possess stealth characteristics.
It provides IP routing.
You must divide up different networks, like any router.
The addition of a SunScreen to your network may require re-numbering IP addresses on your hosts, if you did not already have a router where your SunScreen is being placed.