Cisco Catalyst 6500 Series Configuration Manual page 289

Chapter 15 Using Failover
The only difference in the configuration is the primary and secondary designation, although you must
also pre-configure the failover link on the secondary module before the modules can communicate. All
other configuration is automatically replicated from the active to the standby module.
You can suspend the the configuration replication process using the failover suspend-config-sync
Note
command. See the
The active module sends the configuration in running memory to the standby module. On the standby
module, the configuration exists only in running memory. You can optionally save the configuration to
Flash memory so that when you reboot the standby module when the active module is unavailable, the
standby module can become the active module. To save the configuration to Flash memory after
replication:
For single context mode, enter the copy running-config startup-config command on the active
•
module. The command is replicated to the standby module, which proceeds to write its configuration
to Flash memory.
• For multiple context mode, enter the copy running-config startup-config command on the active
module from the system execution space and within each context on disk. The command is
replicated to the standby module, which proceeds to write its configuration to Flash memory.
Contexts with startup configurations on external servers are accessible from either module over the
network and do not need to be saved separately for each module. Alternatively, you can copy the
contexts on disk from the active module to an external server, and then copy them to disk on the
standby module. (See the
information.)
Configuration replication from the active module to the standby module occurs in the following
circumstances:
When the standby module completes its initial startup, it clears its running configuration (except for
•
the failover commands that must be pre-configured and are not replicated), and the active module
sends its entire configuration to the standby module.
As commands are entered on the active module, they are sent across the failover link to the standby
•
module. You do not have to save the active configuration to Flash memory to replicate the
commands.
If you enter the write standby command on the active module, the standby module clears its running
•
configuration (except for the failover commands that must be pre-configured and are not replicated),
and the active module sends its entire configuration to the standby module.
For multiple context mode, when you enter the write standby command in the system execution
space, all contexts are replicated. If you enter the write standby command within a context, the
command replicates only the context configuration.
Note Changes made on the standby module are not replicated to the active module. If you enter a command
on the standby module, the FWSM displays the message "**** WARNING **** Configuration
Replication is NOT performed from Standby module to Active module. Configurations are no longer
synchronized." This message displays even when you enter many commands that do not affect the
configuration.
When the replication starts, the FWSM console displays the message "Beginning configuration
replication: Sending to mate," and when it is complete, the FWSM displays the message "End
Configuration Replication to mate." During the replication, information cannot be entered on the FWSM
terminal. Depending on the size of the configuration, replication can take several minutes.
OL-6392-01
"Disabling Configuration Synchronization" section on page
"Downloading a Text Configuration" section on page 16-6
Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide
Understanding Failover
15-12.
for more
15-11