Example for Configuring Single-hop BFD for Detecting Faults on a Layer 2 Link

Networking Requirements

As shown in Figure 1, SwitchA and SwitchB are connected through a Layer 2 interface. Faults on the link between SwitchA and SwitchB need to be fast detected.

Figure 1 Single-hop BFD for detecting faults on a Layer 2 link

Configuration Roadmap

The configuration roadmap is as follows:

Configure BFD sessions on SwitchA and SwitchB to detect faults on the link between SwitchA and SwitchB.

Procedure

Configure single-hop BFD on SwitchA.

# Enable BFD on SwitchA.

<HUAWEI> system-view
[HUAWEI] sysname SwitchA
[SwitchA] bfd
[SwitchA-bfd] quit

# Create a BFD session on SwitchA.

[SwitchA] bfd atob bind peer-ip default-ip interface gigabitethernet 0/0/1
[SwitchA-bfd-session-atob] discriminator local 1
[SwitchA-bfd-session-atob] discriminator remote 2
[SwitchA-bfd-session-atob] commit
[SwitchA-bfd-session-atob] quit

Configure single-hop BFD on SwitchB.

# Enable BFD on SwitchB.

<HUAWEI> system-view
[HUAWEI] sysname SwitchB
[SwitchB] bfd
[SwitchB-bfd] quit

# Create a BFD session on SwitchB.

[SwitchB] bfd btoa bind peer-ip default-ip interface gigabitethernet 0/0/1
[SwitchB-bfd-session-btoa] discriminator local 2
[SwitchB-bfd-session-btoa] discriminator remote 1
[SwitchB-bfd-session-btoa] commit
[SwitchB-bfd-session-btoa] quit

Verify the configuration.

After the configuration is completed, run the display bfd session all verbose command on SwitchA and SwitchB. You can see that a single-hop BFD session is set up and its status is Up.

The command output on SwitchA is used as an example.

[SwitchA] display bfd session all verbose
--------------------------------------------------------------------------------
Session MIndex : 4097      (One Hop) State : Up        Name : atob
--------------------------------------------------------------------------------
  Local Discriminator    : 1              Remote Discriminator   : 2
  Session Detect Mode    : Asynchronous Mode Without Echo Function
  BFD Bind Type          : Interface(GigabitEthernet0/0/1)
  Bind Session Type      : Static
  Bind Peer IP Address   : 224.0.0.184
  NextHop Ip Address     : 224.0.0.184
  Bind Interface         : GigabitEthernet0/0/1
  FSM Board Id           : 0                TOS-EXP                : 7
  Min Tx Interval (ms)   : 1000             Min Rx Interval (ms)   : 1000
  Actual Tx Interval (ms): 1000             Actual Rx Interval (ms): 1000
  Local Detect Multi     : 3                Detect Interval (ms)   : 3000
  Echo Passive           : Disable          Acl Number             : -
  Destination Port       : 3784             TTL                    : 255 
  Proc Interface Status  : Disable          Process PST            : Disable
  WTR Interval (ms)      : -                  
  Active Multi           : 3                DSCP                   : - 
  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  : -
  PDT Index              : FSM-0 | RCV-0 | IF-0 | TOKEN-0
  Session Description    : -
--------------------------------------------------------------------------------
 
     Total UP/DOWN Session Number : 1/0

# Run the shutdown command on GE0/0/1 of SwitchA to simulate a link fault.

[SwitchA] interface gigabitethernet 0/0/1
[SwitchA-GigabitEthernet0/0/1] shutdown
[SwitchA-GigabitEthernet0/0/1] quit

After the configuration is completed, run the display bfd session all verbose command on SwitchA and SwitchB. You can see that a single-hop BFD session is set up and its status is Down. The command output on SwitchA is used as an example.

[SwitchA] display bfd session all verbose
--------------------------------------------------------------------------------
Session MIndex : 4097      (One Hop) State : Down        Name : atob
--------------------------------------------------------------------------------
  Local Discriminator    : 1              Remote Discriminator   : 2
  Session Detect Mode    : Asynchronous Mode Without Echo Function
  BFD Bind Type          : Interface(GigabitEthernet0/0/1)
  Bind Session Type      : Static
  Bind Peer IP Address   : 224.0.0.184
  NextHop Ip Address     : 224.0.0.184
  Bind Interface         : GigabitEthernet0/0/1
  FSM Board Id           : 0                TOS-EXP                : 7
  Min Tx Interval (ms)   : 1000             Min Rx Interval (ms)   : 1000
  Actual Tx Interval (ms): 13000            Actual Rx Interval (ms): 13000
  Local Detect Multi     : 3                Detect Interval (ms)   : -
  Echo Passive           : Disable          Acl Number             : -
  Destination Port       : 3784             TTL                    : 255 
  Proc Interface Status  : Disable          Process PST            : Disable
  WTR Interval (ms)      : -                  
  Active Multi           : 3                DSCP                   : - 
  Last Local Diagnostic  : Control Detection Time Expired
  Bind Application       : No Application Bind
  Session TX TmrID       : 16402            Session Detect TmrID   : -
  Session Init TmrID     : -                Session WTR TmrID      : -
  Session Echo Tx TmrID  : -
  PDT Index              : FSM-0 | RCV-0 | IF-0 | TOKEN-0
  Session Description    : -
--------------------------------------------------------------------------------
 
     Total UP/DOWN Session Number : 0/1

Configuration Files

SwitchA configuration file

#
sysname SwitchA
#
bfd
#
bfd atob bind peer-ip default-ip interface GigabitEthernet0/0/1
 discriminator local 1
 discriminator remote 2
 commit
#
return

SwitchB configuration file

#
sysname SwitchB
#
bfd
#
bfd btoa bind peer-ip default-ip interface GigabitEthernet0/0/1
 discriminator local 2
 discriminator remote 1
 commit
#
return