Cisco Catalyst 4500 Series Software Configuration Guide

5-56
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 5 Configuring Virtual Switching Systems
In-Service Software Upgrade (ISSU) on a VSS
Dual-active fast-hello link counters:
Tx Rx
Port OK OK
--------------------------------------
Gi1/1/5 762 759
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:
total = 465
Received:
total = 465
Executing the command on VSS member switch role = VSS Standby, id = 1
Dual-active fast-hello packet counters:
SwitchId : 1
Transmitted:
total = 465
Received:
total = 465
In-Service Software Upgrade (ISSU) on a VSS
Topics include
• VSS ISSU Concept, page 5-56
• Traffic and Network Protocol Disruption During ISSU in a VSS, page 5-57
• Related Documents, page 5-58
• Prerequisites to Performing ISSU, page 5-58
• About Performing ISSU, page 5-59
• How to Perform the ISSU Process, page 5-64
• License installation and subsequent VSS formation are now complete., page 5-85
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.
Figure 5-9 below depicts (at a conceptual level) the sequence of events that take place when the VSS
system is upgraded from software version X to version Y.

Cisco Catalyst 4500 Series Specifications

General

Series	Catalyst 4500 Series
Category	Switch
Layer Support	Layer 2, Layer 3
Form Factor	Modular chassis
Stackable	No
Chassis Slots	3, 6, 7, 10
Power Supply Options	AC, DC
Redundancy	Power supply, Supervisor engine
Network Management	Cisco IOS Software CLI, SNMP, Cisco Prime Infrastructure
Features	Security, QoS
Port Density	Up to 384 ports per chassis
Security Features	802.1X, ACLs, DHCP Snooping, Dynamic ARP Inspection, IP Source Guard
Supervisor Engine	8-E