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User Guide for Cisco Secure Access Control System 5.3
OL-24201-01
Chapter 17 Configuring System Operations
Understanding Distributed Deployment

Understanding Full Replication

Under normal circumstances, each configuration change is propagated to all secondary instances. Unlike
ACS 4.x where full replication was performed, in ACS 5.3, only the specific changes are propagated. As
configuration changes are performed, the administrator can monitor (on the Distributed System
Management page) the status of the replication and the last replication ID to ensure the secondary server
is up to date.
If configuration changes are not being replicated as expected, the administrator can request a full
replication to the server. When you request full replication, the full set of configuration data is
transferred to the secondary server to ensure the configuration data on the secondary server is re
synchronized. The primary ACS transmits the compressed, encrypted copy of its database components
to the secondary ACS.
Note Replication on the Message Bus happens over TCP port 61616. Full replication happens over the Sybase
DB TCP port 2638.
Related Topics
•Activating Secondary Servers, page 17-3
•Promoting a Secondary Server, page 17-4
•Understanding Local Mode, page 17-4

Specifying a Hardware Replacement

You can perform a hardware replacement to allow new or existing ACS instance hardware to re-register
to a primary server and take over an existing configuration already present in the primary server. This is
useful when an ACS instance fails and needs physical replacement.
To perform the hardware replacement
Step 1 From the web interface of the primary instance, you must mark the server to be replaced as deregistered.
Step 2 From the secondary server, register to the primary server.
In addition to the standard admin credentials for connecting to the primary server (username/password),
you must specify the replacement keyword used to identify the configuration in the primary server. The
keyword is the hostname of the instance that is to be replaced.
Step 3 You must active the secondary server on the primary, either automatically or by issuing a manual request.
Related Topics
•Viewing and Editing a Primary Instance, page 17-8
•Viewing and Editing a Secondary Instance, page 17-12
•Activating a Secondary Instance, page 17-13
•Registering a Secondary Instance to a Primary Instance, page 17-13
•Deregistering Secondary Instances from the Distributed System Management Page, page 17-16
•Promoting a Secondary Instance from the Distributed System Management Page, page 17-17