Cisco Catalyst 4500 Series, Software Configuration Manual

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Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 1 Product Overview
Layer 3 Software Features
Bidirectional Forwarding Detection
Note
Starting with Cisco IOS Release IOS 15.1(1)SG, Bidirectional Forwarding Detection (BFD) support was
introduced on Catalyst 4900M, Catalyst 4948E, and Catalyst 4948E-F Ethernet switches. With Cisco
IOS XE 3.5.0E and IOS 15.2(1)E, supported was extended to Supervisor Engine 7-E, and Supervisor
Engine 7L-E. With Cisco IOS XE 3.6.0E and IOS 15.2(2)E, supported was extended to Supervisor
Engine 8-E.
Bidirectional Forwarding Detection (BFD) protocol. BFD is a detection protocol designed to provide
fast forwarding path failure detection times for all media types, encapsulations, topologies, and routing
protocols. It includes a description of how to configure multihop BFD sessions. BFD provides a
consistent failure detection method for network administrators in addition to fast forwarding path failure
detection.
For information on configuring BFD, see Chapter 40, “Configuring Bidirection Forwarding Detection.”
Cisco Express Forwarding
Cisco Express Forwarding (CEF) is an advanced Layer 3 IP-switching technology. CEF optimizes
network performance and scalability in networks with large and dynamic traffic patterns, such as the
Internet, and on networks that use intensive web-based applications or interactive sessions. Although
you can use CEF in any part of a network, it is designed for high-performance, highly resilient Layer 3
IP-backbone switching.
For information on configuring CEF, see Chapter 36, “Configuring Cisco Express Forwarding.”
Device Sensor
Device Sensor uses protocols such as Cisco Discovery Protocol (CDP), Link Layer Discovery Protocol
(LLDP), and DHCP to obtain endpoint information from network devices and make this information
available to its clients. Device Sensor has internal clients, such as the embedded Device Classifier (local
analyzer), Auto Smartports (ASP), MediaNet Service Interface (MSI)-Proxy, and EnergyWise. Device
Sensor also has an external client, Identity Services Engine (ISE), which uses RADIUS accounting to
receive and analyze endpoint data. When integrated with ISE, Device Sensor provides central policy
management and device-profiling capabilities.
For more information on Device Sensor, see Chapter 49, “Configuring 802.1X Port-Based
Authentication.”
EIGRP Stub Routing
The EIGRP stub routing feature, available in all images, reduces resource utilization by moving routed
traffic closer to the end user.
The IP base image contains only EIGRP stub routing. The IP services image contains complete EIGRP
routing.
In a network using EIGRP stub routing, the only route for IP traffic to follow to the user is through a
switch that is configured with EIGRP stub routing. The switch sends the routed traffic to interfaces that
are configured as user interfaces or are connected to other devices.