Specifications

CHAPTER
22-1
Cisco MWR 2941 Mobile Wireless Edge Router Release 3.5 Software Configuration Guide, Cisco IOS Release 15.1(3)MR
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22
Configuring Bidirectional Forwarding Detection
Bidirectional Forwarding Detection (BFD) provides a low-overhead, short-duration method of detecting
failures in the forwarding path between two adjacent routers, including the interfaces, data links, and
forwarding planes. BFD is a detection protocol that you enable at the interface and routing protocol
levels.
The following sections describe how to configure BFD on the Cisco MWR 2941:
• Understanding BFD, page 22-1
• Configuring BFD, page 22-1
• Configuration Examples for BFD, page 22-11
Understanding BFD
Cisco supports the BFD asynchronous mode, in which two routers exchange BFD control packets to
activate and maintain BFD neighbor sessions. To create a BFD session, you must configure BFD on both
systems (or BFD peers). After you have enabled BFD on the interface and the router level for the
appropriate routing protocols, a BFD session is created, BFD timers are negotiated, and the BFD peers
begin to send BFD control packets to each other at the negotiated interval.
Configuring BFD
The following sections describe how to configure BFD for each routing protocol:
• Configuring BFD for OSPF, page 22-2
• Configuring BFD Support for BGP Neighbors, page 22-3
• Configuring IPv6 BFD Support for IPv6 BGP Neighbors, page 22-4
• Configuring BFD for IS-IS, page 22-8
• Configuring BFD for Static Routes, page 22-10
For more information about BFD, refer to the IP Routing: BFD Configuration Guide, Cisco IOS Release
15.0S. For a sample BFD configurations, see Configuration Examples for BFD.