Cisco ASR 5000 Series Administration Guide

Interchassis Communication
Chassis configured to support ICSR communicate using periodic Hello messages. These messages are sent
by each chassis to notify the peer of its current state. The Hello message contains information about the chassis
such as its configuration and priority. A dead interval is used to set a time limit for a Hello message to be
received from the chassis' peer. If the standby chassis does not receive an Hello message from the active
chassis within the dead interval, the standby chassis transitions to the active state.
In situations where the SRP link goes out of service, a priority scheme is used to determine which chassis
processes the session. The following priority scheme is used:
•
route modifier
•
chassis priority
•
MIO/UMIO/MIO2 MAC address
Checkpoint Messages
Checkpoint messages are sent from the active chassis to the standby chassis. These messages are sent at
specific intervals and contain all the information needed to recreate the sessions on the standby chassis, if that
chassis were to become active. Once a session exceeds the checkpoint duration, checkpoint data is collected
on the session.
For additional information, refer to the ICSR Checkpointing appendix.
SRP CLI Commands
Exec Mode CLI Commands
Exec mode srp CLI configuration commands can be used to enable, disable and initiate SRP functions. The
table below lists and briefly describes these commands. For complete information see the Exec Mode Commands
(D-S) chapter of the Command Line Interface Reference.
Table 44: srp CLI Commands
DescriptionCommand
Disables the sending of NACK messages from the standby chassis
that may trigger a full checkpoint from the active chassis. Sending
full checkpoints increases SRP bandwidth. This command disables
the NACK feature for a specific micro-checkpoint which is failing
continuously.
srp disable nack micro-chkpt-cmd
Initiates a forced audit between ICSR chassis. This audit ensures
that two ICSR peers are synchronized and identifies any discrepancies
prior to scheduled or unscheduled switchover events.
srp initiate-audit manual-with-sync
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Interchassis Session Recovery
Interchassis Communication

Cisco ASR 5000 Series Specifications

General

Brand	Cisco
Model	ASR 5000 Series
Category	Network Router
Language	English