Static Routing

Multiple context mode does not support dynamic routing, so you must define static routes for any networks to which the security appliance is not directly connected.

In transparent firewall mode, for traffic that originates on the security appliance and is destined for a non-directly connected network, you need to configure either a default route or static routes so the security appliance knows out of which interface to send traffic. Traffic that originates on the security appliance might include communications to a syslog server, Websense or N2H2 server, or AAA server. If you have servers that cannot all be reached through a single default route, then you must configure static routes.

The simplest option is to configure a default route to send all traffic to an upstream router, relying on the router to route the traffic for you. However, in some cases the default gateway might not be able to reach the destination network, so you must also configure more specific static routes. For example, if the default gateway is on the outside interface, the default route cannot direct traffic to any inside networks that are not directly connected to the security appliance.

You can also use static route in conjunction with dynamic routing protocols to provide a floating static route that is used when the dynamically discovered route goes down. If you create a static route with an administrative distance greater than the administrative distance of the dynamic routing protocol, then a route to the specified destination discovered by the routing protocol takes precedence over the static route. The static route is used only if the dynamically discovered route is removed from the routing table.