Configuring Auto-Rollover, Load Balancing, And Failure Detection - Cisco Small Business Pro SA 520W Administration Manual

Networking
Configuring the Optional WAN
Cisco SA 500 Series Security Appliances Administration Guide
Configuring Auto-Rollover, Load Balancing, and Failure
Detection
If you configured two ISP links, one for the dedicated WAN and one for the optional
WAN, you can configure the WAN Mode to determine how the two ISP links are
used. You can choose from these features:
• Auto-Rollover: Enable this feature when you want to use one ISP link as a
backup. If a failure is detected on the link that you specify as 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. You can designate either
the Dedicated WAN port or the Optional WAN port as the primary link.
Figure 6 shows an example of Dual WAN ports configured with Auto-Roller.
Figure 6 Example Dual WAN Ports with Auto-Roller
Dual WAN Ports (Before Rollover)
WAN1 IP
SA 500
yourcompany.dyndns.org
X
WAN2 port inactive
WAN2 IP (N/A)
• Load Balancing: Enable this feature when you want to use both ISP links
simultaneously. The two links will carry data for the protocols that are bound
to them. You can use this feature to segregate traffic between links that are
not of the same speed. For example, bind high-volume services through the
port that is connected to a high speed link, and bind low-volume services to
the port that is connected to the slower link.
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 addresses public and keeping the other one private.
Figure 7 shows an example of Dual WAN Ports configured with Load
Balancing.
Dual WAN Ports (After Rollover)
SA 500
Internet
X
WAN1 IP (N/A)
WAN1 port inactive
X X
Internet
yourcompany.dyndns.org
WAN2 IP
3
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