Default Bfd Configuration; Default Bfd Configuration Guidelines - Cisco IE-4000 Software Configuration Manual

Configuring IP Unicast Routing
Configuring BFD
You can enable or disable echo processing at a switch interface independent of the BFD neighbor configuration.
Disabling echo mode only disables the sending of echo packets by the interface. The fast-switching layer that receives
an echo packet always reflects it back to the sender.
To run BFD on a switch, you need to configure basic BFD interval parameters on BFD interfaces, enable routing on the
switch, and enable one or more one routing protocol clients for BFD. You also need to confirm that Cisco Express
Forwarding (CEF) is enabled (the default) on participating switches.
For more information on the configuration and commands, see the BFD documents listed in the
page 924.
This section includes the following topics:

Default BFD Configuration, page 885

Default BFD Configuration Guidelines, page 885

Configuring BFD Session Parameters on an Interface, page 886

Enabling BFD Routing Protocol Clients, page 887

Default BFD Configuration


No BFD sessions are configured. BFD is disabled on all interfaces.

When configured, BFD version 1 is the default, but switches negotiate for version. Version 0 is also supported.

Standby BFD (for HSRP) is enabled by default.

Asynchronous BFD echo mode is enabled when a BFD session is configured.

Default BFD Configuration Guidelines

The switch supports a maximum of 28 BFD sessions at one time.
To run BFD on a switch:

Configure basic BFD interval parameters on each interface over which you want to run BFD sessions.

Enable routing on the switch. You can configure BFD without enabling routing, but BFD sessions do not become
active unless routing is enabled on the switch and on the BFD interfaces.

Enable one or more one routing protocol clients for BFD. You should implement fast convergence for the routing
protocol that you are using.
Note: We recommend that you configure the BFD interval parameters on an interface before configuring the routing
protocol commands, especially when using EIGRP.
Confirm that CEF is enabled on participating switches (the default) as well as IP routing.
BFD is supported on physical interfaces that are configured as routing interfaces. It is not supported on Layer 2 interfaces,
pseudowires, static routes, SVI interfaces, or port channels.
Although you can configure BFD interface commands on a Layer 2 port, BFD sessions do not operate on the interface
unless it is configured as a Layer 3 interface (no switchport) and assigned an IP address.
In HSRP BFD, standby BFD is enabled globally by default and on all interfaces. If you disable it on an interface, you then
must disable and reenable it globally for BFD sessions to be active.
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Related Documents,