Cisco ASA 5505 - Manual (Page 447)

C H A P T E R
22-1
Cisco ASA 5500 Series Configuration Guide using the CLI
22
Configuring Static and Default Routes
This chapter describes how to configure static and default routes on the ASA and includes the following
sections:
• Information About Static and Default Routes, page 22-1
• Licensing Requirements for Static and Default Routes, page 22-2
• Guidelines and Limitations, page 22-2
• Configuring Static and Default Routes, page 22-2
• Monitoring a Static or Default Route, page 22-6
• Configuration Examples for Static or Default Routes, page 22-8
• Feature History for Static and Default Routes, page 22-8
Information About Static and Default Routes
To route traffic to a nonconnected host or network, you must define a static route to the host or network
or, at a minimum, a default route for any networks to which the ASA is not directly connected; for
example, when there is a router between a network and the ASA.
Without a static or default route defined, traffic to nonconnected hosts or networks generates the
following syslog message:
%ASA-6-110001: No route to dest_address from source_address
Multiple context mode does not support dynamic routing,
You might want to use static routes in single context mode in the following cases:
• Your networks use a different router discovery protocol from EIGRP, RIP, or OSPF.
• Your network is small and you can easily manage static routes.
• You do not want the traffic or CPU overhead associated with routing protocols.
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 outside, then the default route cannot direct traffic to any inside networks that are not
directly connected to the ASA.
In transparent firewall mode, for traffic that originates on the ASA and is destined for a nondirectly
connected network, you need to configure either a default route or static routes so the ASA knows out
of which interface to send traffic. Traffic that originates on the ASA might include communications to a