User's Manual

Table Of Contents
Networking
Configuring the WAN Redundancy
Cisco ISA500 Series Integrated Security Appliance Administrator Guide 113
4
NOTE When the security appliance is working in Dual WAN mode, if one WAN link is down,
the WAN redundancy and Policy-based Routing settings are ignored and all traffic
is handled by the active WAN port.
This section describes how to configure the WAN redundancy and the link failover
detection settings. It includes the following topics:
Loading Balancing for WAN Redundancy, page 113
Load Balancing with Policy-based Routing Configuration Example,
page 115
Failover for WAN Redundancy, page 116
Routing Table for WAN Redundancy, page 117
Configuring the Link Failover Detection, page 117
Loading Balancing for WAN Redundancy
The Load Balancing can segregate traffic between links that are not of the same
speed. For example, you can bind the high-volume services through the port that
is connected to a high speed link, and bind the low-volume services to the port
that is connected to the slower link.
The Load Balancing is implemented for outgoing traffic and not for incoming traffic.
To maintain better control of WAN port traffic, consider making the WAN port
Internet address public and keeping the other one private.
Figure?2 shows an example of Dual WAN configured with the Load Balancing.
Figure 2 Example of Dual WAN Ports with Load Balancing
ISA500
yourcompany2.dyndns.org
yourcompany1.dyndns.org
Internet
Dual WAN Ports (Load Balancing)
WAN2 IP
WAN1 IP
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