Cisco ASA 5505 Configuration Manual page 372

Monitoring a Static or Default Route
Configuring IPv6 Default and Static Routes
The adaptive security appliance automatically routes IPv6 traffic between directly connected hosts if the
interfaces to which the hosts are attached are enabled for IPv6 and the IPv6 ACLs allow the traffic.
To add or edit a default static route in ASDM, perform the following steps:
In the main ASDM window, choose Configuration > Device Setup > Routing > Static Routes.
Step 1
Click the IPv6 only radio button.
Step 2
Click Add or Edit.
Step 3
Click OK.
Step 4
Monitoring a Static or Default Route
One of the problems with static routes is that there is no inherent mechanism for determining if the route
is up or down. They remain in the routing table even if the next hop gateway becomes unavailable. Static
routes are only removed from the routing table if the associated interface on the adaptive security
appliance goes down.
The static route tracking feature provides a method for tracking the availability of a static route and
installing a backup route if the primary route should fail. This allows you to, for example, define a
default route to an ISP gateway and a backup default route to a secondary ISP in case the primary ISP
becomes unavailable.
The adaptive security appliance does this by associating a static route with a monitoring target that you
define. It monitors the target using ICMP echo requests. If an echo reply is not received within a
specified time period, the object is considered down and the associated route is removed from the routing
table. A previously configured backup route is used in place of the removed route.
When selecting a monitoring target, you need to make sure it can respond to ICMP echo requests. The
target can be any network object that you choose, but you should consider using the following:
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You can configure static route tracking for statically defined routes or default routes obtained through
DHCP or PPPoE. You can only enable PPPoE clients on multiple interface with route tracking.
To monitor the state of a route in ASDM, in the main ASDM window, choose Monitoring > Routing >
Routes.
In this table, each row represents one route.
Cisco ASA 5500 Series Configuration Guide using ASDM
19-8
The ISP gateway (for dual ISP support) address
The next hop gateway address (if you are concerned about the availability of the gateway)
A server on the target network, such as a AAA server, that the adaptive security appliance needs to
communicate with
A persistent network object on the destination network (a desktop or notebook computer that may
be shut down at night is not a good choice)
Chapter 19 Configuring Static and Default Routes
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