Cisco WS-C6506 Software Manual page 739

Chapter 23 Configuring Redundancy
Enter the show redundancy command on the designated router and nondesignated router to ensure that
Step 11
both routers have the following configuration statement:
Single Router Mode RuntimeStatus: enabled
If not, repeat Steps 9 and 10 and allow sufficient time between steps.
Step 12 Enter the reload command to reload the nondesignated router. When asked whether the configuration
should be saved, enter no.
This display summarizes the configuration commands that were used on the designated router and the
nondesignated router to enable SRM redundancy:
Time
----
t0:
t1:
t2:
t3:
t4:
t5:
Specifying the Transition Time on the Newly Designated Active Router
With Cisco IOS releases prior to Release 12.1(11b)E, the transition time was 120 seconds and was not
configurable. Because of the differences in the routing convergence times, 120 seconds might not be long
enough. The older Layer 3 switching entries might be erased, and the newly downloaded Layer 3 switching
information might be incomplete.
With Cisco IOS Release 12.1(11b)E and later releases, you can specify the transition time that the newly
designated router waits before downloading the new Layer 3 switching information to the switch
processor. On a switchover, the old Layer 3 switching information is used for a configurable number of
seconds before the new Layer 3 switching information is downloaded to the switch processor.
If nonstop forwarding is required, we do not recommend setting the transition time to a value that is
lower than the default (120 seconds). At a minimum, it takes 30 to 60 seconds for routes to converge.
To specify the transition time, enter these commands (in this example, the transition time is set to
240 seconds):
Router(config)# redundancy
Router(config-r)# high-availability
Router(config-r-ha)# single-router-mode
Router(config-r-ha)# single-router-mode failover ?
Router(config-r-ha)# single-router-mode failover table-update-delay ?
Router(config-r-ha)# single-router-mode failover table-update-delay 240
Router(config-r-ha)#
To set the transition time to the 2-minute default, use the no form of the command as follows:
Router(config-r-ha)# no single-router-mode failover table-update-delay
OL-8978-04
Designated Router
---
conf t->red->hi->no config-sync
conf t->red->hi->single-router-mode
write mem
table-update-delay Adjust for routing convergence time
<0-4294967295> Delay in seconds between switch over detection and h/w FIB reload
Nondesignated Router
----
conf t->red->hi->no config-sync
conf t->red->hi->single-router-m
reload
Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
MSFC Redundancy
23-47