Connectivity Guide

• multiplier number — Enter the number of consecutive packets that must not be received from a BFD peer before the
session state changes to Down, from 3 to 50; default 3.
• role {active | passive} — Enter active if the router initiates BFD sessions. Both BFD peers can be active at the same
time. Enter passive if the router does not initiate BFD sessions, and only responds to a request from an active BFD to initialize a
session. The default is active.
2 Enable BFD globally in CONFIGURATION mode.
bfd enable
To verify that BFD is globally enabled, enter the show running-config bfd command.
BFD global conguration
OS10(config)# bfd interval 250 min_rx 300 multiplier 4 role passive
OS10(config)# bfd enable
OS10(config)# do show running-config bfd
!
bfd enable
bfd interval 250 min_rx 300 multiplier 4 role passive
BFD for BGP
In a BGP core network, BFD enables faster network reconvergence. BFD rapidly detects communication failures in BGP fast-forwarding
paths between internal BGP (iBGP) and external BGP (eBGP) peers. BFD for BGP is supported on physical, port-channel, and VLAN
interfaces. BFD for BGP does not support the BGP multihop feature.
Before conguring BFD for BGP, rst congure BGP on the interconnecting routers. For more information, see Border Gateway Protocol.
BFD for BGP example
In this BFD for BGP conguration example, Router 1 and Router 2 use eBGP in a transit network to interconnect AS1 and AS2. The eBGP
routers exchange information with each other and with iBGP routers to maintain connectivity and accessibility within each autonomous
system.
When you congure a BFD session with a BGP neighbor, you can:
• Establish a BFD session with a specied BGP neighbor using the neighbor ip-address and bfd commands.
Layer 3
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