Known Behavior
31
Release 10.3.1
We have ongoing development activities to characterize and improve call setup
rates in future releases.
Stateful SRP switchover remains inactive for 20 minutes after an initial
cold-start or cold-restart of the router. This delay enables the system to reach a
stable configuration before starting stateful SRP switchover.
If you want to override the 20-minute timer, turn high availability off by using
the
mode file-system-synchronization
command, and then on again by using
the
mode high-availability
command.
When IP tunnels are configured on a router enabled for stateful SRP
switchover, and the Service Module (SM) carrying these tunnels is reloaded,
stateful SRP switchover transitions to the pending state. Stateful SRP
switchover remains in the pending state for 10 minutes following the
successful reloading of the SM. This amount of time allows for IP tunnel
relocation and for the tunnels to become operational again on the SM. If an SRP
switchover occurs while in the pending state, the router performs a cold restart.
Work-around:
None.
After a stateful SRP switchover, each layer of the interface columns must
reconstruct its interfaces from the mirrored information. While the interfaces
are being reconstructed the SRP module cannot send or receive frames,
including the protocol frames that signal graceful restart behavior with OSPF
and IS-IS peers. If the configured hold time is too short, peers might mistakenly
declare the adjacency down during the time in which the graceful restart is
taking place. [Defect ID 65132]
Work-around
: Increase the hold time to provide sufficient time for interface
synchronization before the peers declare the adjacency down.
For OSPF, use the
ip ospf dead-interval
command to set the hold time.
We recommend that you use Bidirectional Forwarding Detection (BFD)
with a longer OSPF dead interval to achieve fast failure detection.
For IS-IS, use the
isis hello-interval
and
isis hello-multiplier
commands
to set the hold time.
We recommend the following hold times for each protocol, based on the
number of interfaces.
Interface Count
Recommended Hold Time
for OSPF
Recommended Hold Time
for IS-IS
16000 or less
80 seconds
50 seconds
16001 to 32000
87 seconds
55 seconds
32001 to 48000
90 seconds
70 seconds