Example for Configuring a One-Arm BFD Echo Session

This section provides an example for configuring a one-arm BFD echo session on a device that supports BFD.

Networking Requirements

As shown in Figure 1, Device A supports BFD, whereas Device B does not. To rapidly detect faults in the direct link between Device A and Device B, configure a one-arm BFD echo session on Device A. After receiving a one-arm BFD echo session packet from Device A, Device B immediately loops back the packet, implementing rapid link fault detection.

Figure 1 Configuring a one-arm BFD echo session

Interfaces 1 in this example are GE 0/1/0.

Configuration Roadmap

The configuration roadmap is as follows:

Assign IP addresses to the interfaces through which Device A and Device B are directly connected.
Configure a one-arm BFD echo session on Device A.

Data Preparation

To complete the configuration, you need the following data:

Peer IP address monitored by a one-arm BFD echo session
Local discriminator of a one-arm BFD echo session
Minimum interval at which one-arm BFD echo session packets are received

Procedure

Assign IP addresses to the interfaces through which Device A and Device B are directly connected.

# Assign an IP address to Device A's interface through which Device A is directly connected to Device B.

<HUAWEI> system-view
[~HUAWEI] sysname DeviceA
[*HUAWEI] commit
[~DeviceA] interface gigabitethernet 0/1/0
[~DeviceA-GigabitEthernet0/1/0] undo shutdown
[*DeviceA-GigabitEthernet0/1/0] ip address 10.1.1.1 24
[*DeviceA-GigabitEthernet0/1/0] commit
[~DeviceA-GigabitEthernet0/1/0] quit

# Assign an IP address to Device B's interface through which Device B is directly connected to Device A.

<HUAWEI> system-view
[~HUAWEI] sysname DeviceB
[*HUAWEI] commit
[~DeviceB] interface gigabitethernet 0/1/0
[~DeviceB-GigabitEthernet0/1/0] undo shutdown
[*DeviceB-GigabitEthernet0/1/0] ip address 10.1.1.2 24
[*DeviceB-GigabitEthernet0/1/0] commit
[~DeviceB-GigabitEthernet0/1/0] quit

Configure a one-arm BFD echo session on Device A.

# Configure Device A.

[~DeviceA] bfd
[*DeviceA-bfd] quit
[*DeviceA] bfd atob bind peer-ip 10.1.1.2 interface gigabitEthernet0/1/0 one-arm-echo
[*DeviceA-bfd-session-atob] discriminator local 1
[*DeviceA-bfd-session-atob] min-echo-rx-interval 100
[*DeviceA-bfd-session-atob] commit
[~DeviceA-bfd-session-atob] quit
[~DeviceA] quit

Verify the configuration.

After completing the configuration, run the display bfd session all verbose command on Device A. The command output shows that a one-arm BFD echo session has been established and its status is Up.

<DeviceA> display bfd session all verbose
(w): State in WTR  (*): State is invalid
--------------------------------------------------------------------------------
  (One Hop)   State : Up                  Name : atob
--------------------------------------------------------------------------------
  Local Discriminator    : 1                Remote Discriminator   : -
  Session Detect Mode    : Asynchronous One-arm-echo Mode
  BFD Bind Type          : Interface(gigabitEthernet0/1/0)
  Bind Session Type      : Static 
  Bind Peer IP Address   : 10.1.1.2         
  Bind Interface         : GigabitEthernet0/1/0
  Track Interface        : -  
  FSM Board Id           : 10               TOS-EXP                : 7
  Echo Rx Interval (ms)  : 100 
  Actual Tx Interval (ms): 100              Actual Rx Interval (ms): 100 
  Local Detect Multi     : 3                Detect Interval (ms)   : 300 
  Echo Passive           : Disable          Acl Number             : - 
  Destination Port       : 3784             TTL                    : 255 
  Proc Interface Status  : Disable          Process PST            : Disable    
  WTR Interval (ms)      : -                Config PST             : Disable    
  Active Multi           : 3                  
  Last Local Diagnostic  : No Diagnostic
  Bind Application       : No Application Bind
  Session TX TmrID       : -                Session Detect TmrID   : - 
  Session Init TmrID     : -                Session WTR TmrID      : - 
  Session Echo Tx TmrID  : -   
  Session Not Up Reason  : -  
050928
  Session Description    : - 
--------------------------------------------------------------------------------

       Total UP/DOWN Session Number : 1/0

Configuration Files

Device A configuration file

#
 sysname DeviceA
#
 bfd
#
interface gigabitethernet0/1/0
 undo shutdown
 ip address 10.1.1.1 255.255.255.0
#
bfd atob bind peer-ip 10.1.1.2 interface gigabitEthernet0/1/0 one-arm-echo
 discriminator local 1
 min-echo-rx-interval 100
 commit
#
return

Device B configuration file

#
 sysname DeviceB
#
interface gigabitethernet0/1/0
 undo shutdown
 ip address 10.1.1.2 255.255.255.0
#
return