Information About Bfd; Differences In Bfd In Cisco Ios Xr Software And Cisco Ios Software; Bfd Modes Of Operation - Cisco NCS 6000 Series Configuration Manual

Implementing BFD
• Echo latency detection and echo validation are not supported on bundle interfaces.
• Only BGP application is supported on BFD for Multihop Paths.
• Only static and BGP applications are supported on BFD over PWHE.
• Only static, OSPF, IS-IS, and BGP applications are supported on BFD over GRE.

Information About BFD

Differences in BFD in Cisco IOS XR Software and Cisco IOS Software

If you are already familiar with BFD configuration in Cisco IOS software, be sure to consider the following
differences in BFD configuration in the Cisco IOS XR software implementation:
• In Cisco IOS XR software, BFD is an application that is configured under a dynamic routing protocol,
• In Cisco IOS XR software, a BFD neighbor is established through routing. The Cisco IOS bfd neighbor
• Instead of using a dynamic routing protocol to establish a BFD neighbor, you can establish a specific
• A router running BFD in Cisco IOS software can designate a router running BFD in Cisco IOS XR

BFD Modes of Operation

Cisco IOS XR software supports the asynchronous mode of operation only, with or without using echo packets.
Asynchronous mode without echo will engage various pieces of packet switching paths on local and remote
systems. However, asynchronous mode with echo is usually known to provide slightly wider test coverage
as echo packets are self-destined packets which traverse same packet switching paths as normal traffic on the
remote system.
BFD echo mode is enabled by default for the following interfaces:
• For IPv4 on member links of BFD bundle interfaces.
• IPv6 states are not explicitly monitored on a bundle member and they inherit the state of the IPv4
BFD session for that member interface.
• VLAN subinterfaces on a bundle member also inherit the BFD state from the IPv4 BFD session for
that member interface. VLAN subinterfaces are not explicitly monitored on a bundle member.
such as an OSPF or BGP instance. This is not the case for BFD in Cisco IOS software, where BFD is
only configured on an interface.
interface configuration command is not supported in Cisco IOS XR software.
BFD peer or neighbor for BFD responses in Cisco IOS XR software using a method of static routing to
define that path. In fact, you must configure a static route for BFD if you do not configure BFD under a
dynamic routing protocol in Cisco IOS XR software. For more information, see the
Static Route.
software as its peer using the bfd neighbor command; the Cisco IOS XR router must use dynamic routing
or a static route back to the Cisco IOS router to establish the peer relationship. See the
Routers Running Cisco IOS and Cisco IOS XR Software:
Routing Configuration Guide for Cisco NCS 6000 Series Routers, IOS XR Release 6.4.x
Information About BFD
Enabling BFD on a
Example.
BFD Peers on
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