Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual page 483

Chapter 22 Configuring Redundancy
If you change high availability from disabled to enabled, synchronization from the active to standby
supervisor engine is started (provided the standby supervisor engine is present and its image version is
compatible).
NVRAM synchronization occurs irrespective of high availability being enabled or disabled (provided
there are compatible NVRAM versions on the two supervisor engines).
If you do not install a standby supervisor engine during system bootup, the active supervisor engine
detects this and the database updates are not queued for synchronization. Similarly, when you reset or
remove the standby supervisor engine, the synchronization updates are not queued and any pending
updates in the synchronization queue are discarded. When you hot insert or restart a second supervisor
engine that becomes the standby supervisor engine, the active supervisor engine downloads the entire
system database to the standby supervisor engine. Only after this global synchronization is completed,
the active supervisor engine queues and synchronizes the individual updates to the standby supervisor
engine.
When you hot insert or restart a second supervisor engine, it might take a few minutes for the global
Note
synchronization to complete.
High-Availability Supported Features
MLS flows are preserved from the active supervisor engine to the standby supervisor engine.
Note
High availability does not preserve routing table entries on the active MSFC because high
Note
availability is not run on the MSFC IOS software. However, you can configure both MSFCs on the
active and standby supervisor engines with the same configuration to preserve routing table entries
across the active and standby MSFCs. You can then configure HSRP on the MSFCs to provide
automatic routing backup. See the
information.
High availability for the Catalyst 6000 family switch is classified into three categories (see
•
•
•
Timers and statistics are not synchronized from the active to the standby supervisor engine.
Note
78-13315-02
Supported features—High availability is fully supported; the feature's database is synchronized
from the active supervisor engine to the standby supervisor engine.
Compatible features—High availability is not supported; the feature's database is not synchronized
from the active supervisor engine to the standby supervisor engine. However, the feature can be
enabled (operational) with high availability.
Incompatible features—High availability is not supported; the feature's database is not
synchronized from the active supervisor engine to the standby supervisor engine. The feature cannot
be enabled if high availability is enabled and similarly, high availability cannot be enabled if the
feature is enabled.
"MSFC Redundancy" section on page 22-18
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
Configuring Redundant Supervisor Engines
for detailed
Table 22-1):
22-9