Reference Guide

Bidirectional Forwarding Detection | 187
View the established sessions using the command show bfd neighbors, as shown in the following example.
R2(conf-if-vl-200)#bfd neighbor 2.2.3.2
R2(conf-if-vl-200)#do show bfd neighbors
* - Active session role
Ad Dn - Admin Down
C - CLI
I - ISIS
O - OSPF
R - Static Route (RTM)
V - VRRP
LocalAddr RemoteAddr Interface State Rx-int Tx-int Mult Clients
* 2.2.3.2 2.2.3.1 Vl 200 Up 100 100 3 C
Changing session parameters
BFD sessions are configured with default intervals and a default role. The parameters that can be
configured are: Desired TX Interval, Required Min RX Interval, Detection Multiplier, and system role.
These parameters are configured per interface; if a configuration change is made, the change affects all
sessions on that interface.
To change session parameters on an interface:
View session parameters using the command
show bfd neighbors detail, as shown in the example in
Changing physical port session parameters.
Disabling BFD for VLANs
If BFD is disabled on an interface, sessions on the interface are torn down. A final Admin Down control
packet is sent to all neighbors, and sessions on the remote system change to the Down state (Message 3).
To disable BFD on a VLAN interface:
Caution: When configuring BFD on VLAN or LAG interfaces on the C-Series, Dell Force10 recommends
a minimum value of 500 milliseconds for both the transmit and minimum receive time, which yields a final
detection time of (500ms *3) 1500 milliseconds.
Step Task Command Syntax Command Mode
1 Change session parameters for all
sessions on an interface.
bfd interval milliseconds min_rx
milliseconds multiplier value role [active |
passive]
INTERFACE VLAN
Step Task Command Syntax Command Mode
1 Disable all sessions on a VLAN
interface.
no bfd enable INTERFACE VLAN