C H A P T E R 37 Configuring Bidirection Forwarding Detection - Cisco Catalyst 4500 Series Configuration Manual

Prerequisites for Bidirectional Forwarding Detection
Prerequisites for Bidirectional Forwarding Detection
Prerequisites include:
•
•
Restrictions for Bidirectional Forwarding Detection
Restrictions include:
•
Cisco IOS Release 15.1(1)SG and Cisco Catalyst 4500 Series Switches
•
Note
•
•
For the most accurate platform and hardware restrictions, see the Cisco IOS software release notes for
Note
your software version.
Information About Bidirectional Forwarding Detection
•
•
BFD Operation
BFD provides a low-overhead, short-duration method of detecting failures in the forwarding path
between two adjacent switches, including the interfaces, data links, and forwarding planes.
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
37-2
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
on page 37-2 for more information on BFD routing protocol support in Cisco IOS software.
BFD works only for directly connected neighbors. BFD neighbors must be no more than one IP hop
away. Multihop configurations are not supported.
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.
Starting with Cisco IOS Release IOS 15.1(1)SG, Bidirectional Forwarding Detection (BFD) is
supported only on Catalyst 4900M, and Catalyst 4948E Ethernet switches
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.
BFD Operation, page 37-2
Benefits of Using BFD for Failure Detection, page 37-6
Chapter 37 Configuring Bidirection Forwarding Detection
"Restrictions for Bidirectional Forwarding Detection" section
OL-25340-01