Reference Guide

Bidirectional Forwarding Detection (BFD) | 101

Figure 7-3. BFD State Machine

Important Points to Remember

• BFD for line card ports is hitless, but is not hitless for VLANs since they are instantiated on the RPM.

• FTOS supports a maximum of 100 sessions per BFD agent. Each stack-unit processor has a BFD

Agent, so the limit translates to 100 BFD sessions per stack-unit.

• BFD must be enabled on both ends of a link.

• Demand mode, authentication, and the Echo function are not supported.

• BFD is not supported on multi-hop and virtual links.

• Protocol Liveness is supported for routing protocols only.

• FTOS supports only OSPF, IS-IS( only), BGP ( only), and VRRP (not on )

protocols as BFD clients.

Configuring Bidirectional Forwarding Detection

The remainder of this chapter is divided into the following sections:

• Configuring BFD for OSPF

• Configuring BFD for IS-IS

• Configuring BFD for BGP

• Configuring Protocol Liveness

• To enable Protocol Liveness:

Configuring BFD for OSPF

BFD for OSPF is only supported on platforms:

Router A Router B

Router C

Router D

Router E

Router G

Router F

Router H

{

eBGP Route

{

eBGP Route

Route Reflector

Route Reflector Client Peers

iBGP Route

iBGP Routes