5-2
ATM Switch Router Software Configuration Guide
OL-7396-01
Chapter5 Configuring Redundancy
Route Processor Redundant Operation (Catalyst 8540 MSR)
When the Catalyst 8540 MSR is powered on, the two route processors go through an arbitration to
determine which is the primary route processor and which is the secondary. The following rules apply
during arbitration:
•A newly inserted route processor card always comes up as the secondary, except in cases where the
newly inserted card is the only one present.
•If the configuration is corrupted, one of the route processors comes up as pri mary, allowing you to
correct the situation manually.
•The primary route processor at the time the Catalyst 854 0 MSR is powered off continues as the
primary when the Catalyst 8540 MSR is powered on.
•If none of the above conditions is true, the route processor in slot4 becomes the primary.
During normal operation, the primary route processor is booted completely. The secondary CPU is
partially up, meaning it stops short of parsing the configuration. From this point, the primary and
secondary processors communicate periodically to synchronize any syste m configuration changes.
The following situations can cause a switchover of the primary route processor:
•The primary route processor is removed or swapped. When a route processor functioning as primary
is removed, the secondary takes over. The Catalyst8540 MSR is now nonredundant until a second
route processor is inserted.
•The primary route processor is rebooted. When a route pro cessor functioning as primary is rebooted,
the secondary take s over.
•The primary route processor fails. The secondary route processor takes over as primary, using the
last saved configuration (or the current running configuration if they have been synchronized with
the sync config command).
•A switchover is manually forced with the redundancy force-failover main-cpu command.
When a switchover occurs, permanent virtual connections (PVCs) are preserved. Transit switched virtual
circuits (SVCs) and soft PVCs are preserved if the switch is configured to synchronize dynamic
information (see the Synchronizing the Dynamic Information (Cata lyst 8540 MSR), page
5-7).Terminating SVCs and Integrated Local Management Interface (ILMI) address states are lost, and
then restored after they are dynamically redetermined.
Table 5 -1 lists various ATM connection types and whether or not they ar e preserved during a route
processor switchover.
Table5-1 Connection Preservation During Route Processor Switchover
Connection Type Preserved During Switchover
PVC Yes
PVP Yes
Point-to-Multipoint PVC Yes
Point-to-Multipoint PVP Yes
SVC Yes
SVP Yes
Point-to-Multipoint SVC Yes
MP2P SVC Yes
Point-to-Multipoint SVP Yes
Soft PVC (single-ended) Yes