User's Manual

Networking
Configuring the WAN Redundancy
Cisco ISA500 Series Integrated Security Appliance Administrator Guide 116
4
Failover for WAN Redundancy
Use the Failover mode when you want to use one ISP link as a backup. If a failure is
detected on the primary link, then the security appliance directs all Internet traffic
to the backup link. When the primary link regains connectivity, all Internet traffic is
directed to the primary link and the backup link becomes idle. By default, the
primary WAN is set as the primary link and the secondary WAN is set to the
backup link.
NOTE When the security appliance is working in the Failover mode, the Policy-based
Routing settings will be ignored.
Figure?3 shows an example of Dual WAN configured with Failover.
Figure 3 Example Dual WAN Ports with Failover
STEP 1 Click Networking -> WAN Redundancy -> WAN Redundancy Operation
Configuration.
The WAN Redundancy Operation Configuration opens.
STEP 2 Choose Failover if you want to use one ISP link as a backup and enter the
following information:
• Auto Failover to: Choose either WAN1 or WAN2 as the primary link. By
default, WAN1 is set as the primary link and WAN2 is set as the backup link.
You can also set WAN2 as the primary link.
• Preempt Delay Timer: Enter the time in seconds that the system will
preempt the primary link from the backup link when the primary link is up
again. The default is 5 seconds.
STEP 3 Click Save to apply your settings.
ISA500
yourcompany.dyndns.org
XX
WAN2 port inactive
WAN2 IP (N/A)
Internet
Dual WAN Ports (Before Rollover)
ISA500
yourcompany.dyndns.org
XX
WAN1 IP (N/A)
WAN1 port inactive
Internet
Dual WAN Ports (After Rollover)
WAN1 IP
WAN2 IP
197401