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Chapter 5: Operation
Figure 5-1. Auto Failover and Manual Recovery.
NOTE: The A/B Switch monitors the WAN connections by PINGing the far side router through the primary WAN link. If the
primary WAN link fails, the A/B Switch auto switches to the backup WAN link. Auto recovery is disabled in this
configuration to prevent flapping.
Figure 5-2. Auto Failover and Auto Recovery.
NOTE: The A/B Switch monitors the WAN connections by PINGing the far side router through the primary WAN link. If the
primary WAN link fails, the A/B Switch auto switches to the backup WAN link. When the primary WAN link is available
again, the A/B Switch auto switches back to the primary.
The monitorip address and monitormac address parameters can be configured to allow the A/B Switch to monitor connectivity to
any device within, or outside of the A/B Switch’s subnet. If monitoring connectivity to a device on the same subnet as the A/B
Switch’s internal Ethernet node, set the A/B Switch’s monitorip address and monitormac address parameters to the IP address and
MAC address of the device being monitored. If monitoring connectivity to a device on a different subnet/network than the A/B
Switch’s internal Ethernet node, set the A/B Switch’s monitormac address parameter to the MAC address of the gateway router
on the A/B Switch’s subnet, and set the monitorip address parameter to the IP address of the device being monitored. This allows
the PING packet issued by the A/B Switch to be routed through the gateway router to the target device on a different subnet/
network. If you don’t know the MAC address of the target device or the gateway router on the A/B Switch’s subnet, one method
is to open a command prompt window on a P.C. attached to that same subnet and use the “arp -a” command to retrieve this
information from the P.C.’s arp cache (you may need to PING the IP address first before the entry will appear in the arp cache).
In most network environments, rather than manually configuring the monitormac address, you can configure the A/B Switch to
automatically determine the proper MAC address required for the PING packet. Enter the monitorip address information as noted
above, and then set the monitormac address parameter to 00 00 00 00 00 00. This causes the A/B Switch to issuing an ARP
request to the gateway router which will respond with the appropriate MAC address information needed.
NOTE: When the Auto Switch feature is enabled, manual switching can be performed, but will be overridden by any auto
switching commands that are subsequently issued by the A/B Switch.
