Alcatel-Lucent 6850-48 ネットワークガイド

Configuring BFD

Configuring BFD

OmniSwitch AOS Release 6 Network Configuration Guide

page 30-15

-> ip bfd-std interface bfd-vlan-101 receive 500

The above command changes the receive time interval value to 500 msecs on the BFD interface named 
bfd-vlan-101. 

The global receive time interval serves as the default interval value for a BFD interface. The default inter-
val value is overridden when a specific value is configured for the interface. 

As previously mentioned, BFD operates in two modes: Echo and Asynchronous mode. The Echo function 
can be used alone or simultaneously with the Asynchronous mode. By default, BFD is configured to oper-
ate in the Asynchronous mode with the Echo function enabled

To change the global operational mode and echo status of BFD, use the 

 command, as 

shown below:

-> ip bfd-std mode asynchronous echo disable

The above command configures BFD to globally operate in the asynchronous mode with the echo func-
tion disabled.

The BFD operational mode and echo status is also configurable at the BFD interface level. To change the 
operational mode of a specific BFD interface, use the 

 command along with the 

interface name. For example:

-> ip bfd-std interface bfd-vlan-101 mode echo-only

The above command sets the operational mode of BFD interface named bfd-vlan-101 to echo only.

The global operating mode and Echo function status serves as the default mode for a BFD interface.The 
global mode and status is overridden when a specific value is configured for the interface.

The time interval between received BFD echo packets is configurable and applies when the echo function 
is enabled. When this function is active, a stream of Echo packets is sent to a peer, which then loops these 
back to the sender without processing them via its forwarding path. If the sender does not receive several 
continuous echo packets from its peer, the BFD session is declared down.

By default, the Echo time interval is set to 100 milliseconds. To change the global BFD echo packet time 
interval, use the 

 command. For example:

-> ip bfd-std echo interval 500

The above command sets the echo interval to 500 milliseconds globally on all BFD interfaces.

To change the BFD echo time interval for a particular BFD interface, use the 

 command. For example: 

-> ip bfd-std interface bfd-vlan-101 echo-interval 500

The above command configures the echo time interval value to 500 milliseconds on BFD interface named 
bfd-vlan-101. 

The global echo packet time interval serves as the default interval value for a BFD interface. The default 
interval value is overridden when a specific value is configured for the interface.