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Cisco 4700 Series Application Control Engine Appliance Administration Guide
OL-11157-01
Chapter 7 Configuring Redundant ACE Appliances
Overview of Redundancy
For multiple contexts, the FT VLAN resides in the system configuration file. Each
FT VLAN on the ACE has one unique MAC address associated with it. The ACE
uses these device MAC addresses as the source or destination MACs for sending
or receiving redundancy protocol state and configuration replication packets.
Note
The IP address and the MAC address of the FT VLAN do not change at
switchover.
Configuration Synchronization
For redundancy to function properly, both members of an FT group must have
identical configurations. Ensure that both ACE appliances include the same
bandwidth software license (2G or 1G) and the same virtual context software
license. If there is a mismatch in software license between the two ACE
appliances in an FT group, the following operational behavior can occur:
•
If there is a mismatch in virtual context software license, synchronization
between the active ACE and standby ACE may not work properly.
•
If both the active and the standby ACE appliances have the same virtual
content software license but have a different bandwidth software license,
synchronization will work properly but the standby ACE may experience a
potential loss of traffic on switchover from the 2G ACE appliance to the 1G
ACE appliance.
See the
Cisco 4700 Series Application Control Engine Appliance Administration
Guide
for details about the available ACE software licenses.
The ACE automatically replicates the active configuration on the standby member
using a process called
configuration synchronization
(config sync). Config sync
automatically replicates any changes made to the configuration of the active
member to the standby member. After the ACE synchronizes the redundancy
configuration from the active member to the standby peer, it disables
configuration mode on the standby.
For information about configuring config sync, see the
“Synchronizing
Redundant Configurations”
section.