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Cisco NAC Guest Server Installation and Configuration Guide
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Chapter 12 Replication and High Availability Deployment Considerations

Device Failure

If one of the Cisco NAC Guest Servers in a replication pair fails and needs to be replaced, you should
set up replication with the working server and the data will be r e-sync hr oniz ed t o t he d evice.
Warning
Do not restore the failed unit from a backup. Restoring from a backup onto one unit in a replication
pair will result in not having an exact replica of the data on both servers.
Step 1 From the administration interface select Authentication > Replication Settings from the left hand menu
(Figure 12-4).
Figure 12-4 Resetting Replication
Step 2 Set Replication Mode to Off on both of the Guest Servers.
Step 3 Follow the instructions in Setting up replication, page 12-1 and ensure that you set the working server
as the one with the data.
Deployment Considerations

Connectivity

The Cisco NAC Guest Servers need to be provided with IP connectivity between the units. Cisco
recommends making the network path between the devices resilient so that synchronization can always
be performed. However if the devices become disconnected they will continue to functio n and st o re
changes until they are connected back together and can re-establish communication. At that point they
will re-synchronize databases.