Cisco WS-X6066-SLB-APC - Content Switching Module Software Manual page 499

Chapter 22 Configuring Redundancy
While the examples are specific to the PFC, the failover scenarios for the PFC2/MSFC2 would be
Note
similar for handling ACLs and CEF table entries. On a Supervisor Engine 2, the designated MSFC2
programs many of the ASICs on the PFC2 including building the CEF table. In a designated MSFC2
HSRP failover to the nondesignated MSFC2, the PFC2 continues to function with the CEF table
programmed by the previously designated MSFC2. Similar to the process with the MLS cache in a
Supervisor Engine 1/MSFC configuration, the newly designated MSFC2 eventually reprograms the
CEF table with its own entries and the old entries age out.
Figure 22-4 Single Chassis with Dual Supervisor Engines and Dual MSFCs
VLAN 10
Failure Case 1: Designated MSFC #1 Fails
This sequence occurs when the designated MSFC #1 fails:
1.
2.
3.
4.
Failure Case 2: Nondesignated MSFC #2 Fails
This sequence occurs when the nondesignated MSFC #2 fails:
1.
2.
3.
4.
78-13315-02
VLAN 21
Slot 1
Sup#1(active)/MSFC#1
HSRP Active VLAN 10: priority 110
HSRP Standby VLAN 21: priority 109
Slot 2
Switch S1
Sup#2(standby)/MSFC#2
HSRP Active VLAN 21: priority 110
HSRP Standby VLAN 10: priority 109
MLS entries for MSFC #1 gracefully age out of the Sup #1 Layer-3 cache, while MSFC #2 takes
temporary ownership of these MLS entries using its XTAG value.
MLS entries for MSFC #2 are not affected.
MSFC #2 removes all dynamic and reflexive ACLs programmed in hardware by MSFC #1.
MSFC #2 reprograms the static ACLs in the Sup #1 ACL ASIC because it is now the designated
MSFC.
MLS entries for MSFC #2 gracefully age out of the Sup #1 Layer 3 cache, while MSFC #1 takes
temporary ownership of these MLS entries using its XTAG value.
MLS entries from MSFC #1 are not affected.
MSFC #1 removes all dynamic and reflexive ACLs programmed in hardware by MSFC #2.
MSFC #1 remains the designated MSFC.
Catalyst 6000 Family Software Configuration Guide—Releases 6.3 and 6.4
MSFC Redundancy
22-25