Cisco Catalyst 4500 Series Administration Guide

39-2
Software Configuration Guide—Release IOS XE 3.6.0E and IOS 15.2(2)SG
OL_28731-01
Chapter 39 Configuring Bidirection Forwarding Detection
Prerequisites for Bidirectional Forwarding Detection
• How to Configure Bidirectional Forwarding Detection, page 39-8
• Configuration Examples for Bidirectional Forwarding Detection, page 39-17
• Additional References, page 39-28
Prerequisites for Bidirectional Forwarding Detection
Prerequisites include:
• IP routing must be enabled on all participating switches.
• One of the IP routing protocols supported by BFD must be configured on the switches before BFD
is deployed. You should implement fast convergence for the routing protocol that you plan to use.
See the IP routing documentation for your version of Cisco IOS software for information on
configuring fast convergence. See the “Restrictions for Bidirectional Forwarding Detection” section
on page 39-2 for more information on BFD routing protocol support in Cisco IOS software.
Restrictions for Bidirectional Forwarding Detection
Restrictions include:
• BFD works only for directly connected neighbors. BFD neighbors must be no more than one IP hop
away. Multihop configurations are not supported.
Cisco IOS Release 15.1(1)SG
• Cisco Catalyst 4500 series switches support up to 128 BFD sessions with a minimum hello interval
of 50 ms and a multiplier of 3. The multiplier specifies the minimum number of consecutive packets
that can be missed before a session is declared down.
• If SSO is enabled on a dual RP system, the following limitations apply:
– The minimum hello interval is 50 ms with a multiplier of 5 or higher.
– Smaller values may be configured but may flap during an SSO switchover.
• To enable echo mode the peer system must be configured with the no ip redirects command.
Cisco IOS Release XE 3.5.0E and IOS 15.2(1)E
• Cisco Catalyst 4500 series switches support up to 100 BFD sessions with a minimum hello interval
of 100 ms and a multiplier of 3. The multiplier specifies the minimum number of consecutive
packets that can be missed before a session is declared down.
• If SSO is enabled on a dual RP system, the following limitations apply:
– The minimum hello interval is 50 ms with a multiplier of 5 or higher.
– Smaller values may be configured but may flap during an SSO switchover.
• To enable echo mode the peer system must be configured with the no ip redirects command.
Note For the most accurate platform and hardware restrictions, see the Cisco IOS software release notes for
your software version.

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