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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
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Chapter 23 Configuring Redundancy
MSFC Redundancy
Step 11
Enter the
show redundancy
command on the designated router and nondesignated router to ensure that
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 Designated Router
Nondesignated Router
---- --- ----
t0: conf t->red->hi->no config-sync
t1: conf t->red->hi->no config-sync
t2: conf t->red->hi->single-router-mode
t3: conf t->red->hi->single-router-m
t4: write mem
t5: reload
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 ?
table-update-delay Adjust for routing convergence time
Router(config-r-ha)#
single-router-mode failover table-update-delay ?
<0-4294967295> Delay in seconds between switch over detection and h/w FIB reload
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
