Cisco Catalyst 4500 Series Administration Guide

35-4
Software Configuration Guide—Release IOS XE 3.5.0E and IOS 15.2(1)E
OL_28731-01
Chapter 35 Configuring Cisco Express Forwarding
Catalyst 4500 Series Switch Implementation of CEF
Figure 35-1 Logical L2/L3 Switch Components
The integrated switching engine performs inter-VLAN routing on logical Layer 3 interfaces with the
ASIC hardware. The ASIC hardware also supports a physical Layer 3 interface that can be configured
to connect with a host, a switch, or a router.
This section contains the following subsections:
• Hardware and Software Switching, page 35-4
• Load Balancing, page 35-6
• Software Interfaces, page 35-6
Hardware and Software Switching
For the majority of packets, the integrated switching engine performs the packet forwarding function in
hardware. These packets are hardware-switched at very high rates. Exception packets are forwarded by
the CPU subsystem software. Statistic reports should show that the integrated switching engine is
forwarding the vast majority of packets in hardware. Software forwarding is significantly slower than
hardware forwarding, but packets forwarded by the CPU subsystem do not reduce hardware forwarding
speed.
Figure 35-2 shows a logical view of the integrated switching engine and the CPU subsystem switching
components.
Integrated Switching Engine (ASIC)
L3 physical
interface
Logical Router
L3 logical
interfaces
L2 switchports
68402
VLAN1
Gig 1/1
VLAN2

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