In-Service Software Upgrade (Issu) On A Vss - Cisco Catalyst 4500 series Administration Manual

Chapter 5 Configuring Virtual Switching Systems
Dual-active fast-hello link counters:
Port
--------------------------------------
Gi1/1/5
This example shows how to display the status of total packets exchanged between the fast-hello links on
the VSS:
Switch# show switch virtual dual-active fast-hello packet
Executing the command on VSS member switch role = VSS Active, id = 2
Dual-active fast-hello packet counters:
SwitchId : 2
Transmitted:
Received:
Executing the command on VSS member switch role = VSS Standby, id = 1
Dual-active fast-hello packet counters:
SwitchId : 1
Transmitted:
Received:

In-Service Software Upgrade (ISSU) on a VSS

Topics include
•
•
•
•
•
•
•
VSS ISSU Concept
In a VSS, the supervisor engines on the peer switches maintain an SSO (stateful switchover) relationship
between themselves. This facilitates the ability to perform a software upgrade (or downgrade) on both
the VSS supervisor engines, one at a time.
Figure 5-9
system is upgraded from software version X to version Y.
OL-30933-01
Tx
OK
762 759
total = 465
total = 465
total = 465
total = 465
VSS ISSU Concept, page 5-55
Traffic and Network Protocol Disruption During ISSU in a VSS, page 5-57
Related Documents, page 5-57
Prerequisites to Performing ISSU, page 5-57
About Performing ISSU, page 5-58
How to Perform the ISSU Process, page 5-63
License install and subsequent VSS formation are now complete., page 5-84
below depicts (at a conceptual level) the sequence of events that take place when the VSS
Rx
OK
Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)SG
In-Service Software Upgrade (ISSU) on a VSS
5-55