Cisco Catalyst 4500 Series Software Configuration Guide

26-12
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 26 Configuring Optional STP Features
About Bridge Assurance
Figure 26-4 shows the network with Bridge Assurance enabled, and the STP topology progressing
normally with bidirectional BDPUs issuing from every STP network port. Figure 26-5 shows how the
potential network problem shown in Figure 26-3 does not occur when you have Bridge Assurance
enabled on your network.
Figure 26-4 Network with STP Topology Running Bridge Assurance
Figure 26-5 Network Problem Averted with Bridge Assurance Enabled
The system generates syslog messages when a port is block or unblocked. The following sample outputs
show the log that is generated for each of these states:
Blocked port:
Sep 17 09:48:16.249 PDT: %SPANTREE-2-BRIDGE_ASSURANCE_BLOCK: Bridge Assurance blocking
port GigabitEthernet5/8 on VLAN0200. (stack-dut-R4-4)
Unblocked Port:
Sep 17 09:48:58.426 PDT: %SPANTREE-2-BRIDGE_ASSURANCE_UNBLOCK: Bridge Assurance
unblocking port GigabitEthernet5/8 on VLAN0200. (stack-dut-R4-4)
Blocked
186526
Edge
Network
Network
Root
Network
Root
BPDUs
354161
Stopped receiving
BPDUs
Stopped receiving
BPDUs
Edge
Network
Network
Network
X

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