Example for Associating a BFD Session and a Sub-interface

This section provides an example for associating a BFD session with a sub-interface to improve service reliability on the sub-interface.

Networking Requirements

On the large metro Ethernet network shown in Figure 1, large numbers of VLAN services are configured on an interface's sub-interface and high reliability is required. Establish a BFD session to monitor the interface's link continuity, and associate the BFD session with the sub-interface. This configuration improves service reliability on the sub-interface and saves BFD session resources.

Figure 1 Association between a BFD session and a sub-interface

Interface 1 in this example represents GE 0/1/0.



Configuration Roadmap

The configuration roadmap is as follows:

  1. Configure a BFD session on Device A.

  2. Configure a BFD session on Device B.

  3. Associate the BFD session and a sub-interface on Device A.

  4. Associate the BFD session and a sub-interface on Device B.

Precautions

BFD sessions must be established on both ends.

Data Preparation

To complete the configuration, you need the following data:

  • IP address of the peer interface on a link to be monitored by BFD

  • IP address of a local interface that sends and receives BFD control packets

  • Local and remote discriminators of BFD sessions

Procedure

  1. Assign IP addresses to interfaces on Device A and Device B, and create sub-interfaces.

    # Configure Device A.

    <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] quit
[*DeviceA] interface gigabitethernet 0/1/0.1
[*DeviceA-GigabitEthernet0/1/0.1] undo shutdown
[*DeviceA-GigabitEthernet0/1/0.1] ip address 10.2.1.1 24
[*DeviceA-GigabitEthernet0/1/0.1] commit
[~DeviceA-GigabitEthernet0/1/0.1] quit

    # Configure Device B.

    <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] quit
[*DeviceB] interface gigabitethernet 0/1/0.1
[*DeviceB-GigabitEthernet0/1/0.1] undo shutdown
[*DeviceB-GigabitEthernet0/1/0.1] ip address 10.2.1.2 24
[*DeviceB-GigabitEthernet0/1/0.1] commit
[~DeviceB-GigabitEthernet0/1/0.1] quit

  2. Configure single-hop BFD.

    # Configure Device A.

    [~DeviceA] bfd
[*DeviceA-bfd] quit
[*DeviceA] bfd pissub bind peer-ip default-ip interface gigabitethernet 0/1/0
[*DeviceA-bfd-session-pissub] discriminator local 1
[*DeviceA-bfd-session-pissub] discriminator remote 2
[*DeviceA-bfd-session-pissub] commit
[~DeviceA-bfd-session-pissub] quit

    # Configure Device B.

    [~DeviceB] bfd
[*DeviceB-bfd] quit
[*DeviceB] bfd pissub bind peer-ip default-ip interface gigabitethernet 0/1/0
[*DeviceB-bfd-session-pissub] discriminator local 2
[*DeviceB-bfd-session-pissub] discriminator remote 1
[*DeviceB-bfd-session-pissub] commit
[~DeviceB-bfd-session-pissub] quit

    # After completing the configurations, run the display bfd session all verbose command on Device A or Device B. The command output shows that a single-hop BFD session has been established and its status is Up. The following example uses the command output on Device A.

    [~DeviceA] display bfd session all verbose
(w): State in WTR  (*): State is invalid
------------------------------------------------------------------------------
  (One Hop)   State : Up                    Name : pissub
---------------------------------------------------------------------------
  Local Discriminator    : 1                Remote Discriminator   : 2
  Session Detect Mode    : Asynchronous Mode Without Echo Function
  BFD Bind Type          : Interface(GigabitEthernet0/1/0)
  Bind Session Type      : Static
  Bind Peer IP Address   : 224.0.0.184
  Bind Interface         : GigabitEthernet0/1/0
  FSM Board Id           : 1                TOS-EXP                : 7
  Min Tx Interval (ms)   : 10               Min Rx Interval (ms)   : 10
  Actual Tx Interval (ms): 10               Actual Rx Interval (ms): 10
  Local Detect Multi     : 3                Detect Interval (ms)   : 30
  Echo Passive           : Disable          Acl Number             : -
  Destination Port       : 3784             TTL                    : 255
  Proc Interface Status  : Disable          Process PST            : Disable
  WTR Interval (ms)      : 0                Local Demand Mode      : Disable
  Active Multi           : 3
  Last Local Diagnostic  : No Diagnostic
  Bind Application       : No Application Bind
  Session TX TmrID       : 0                Session Detect TmrID   : 0
  Session Init TmrID     : -                Session WTR TmrID      : -
  Session Echo Tx TmrID  : -
  Session Description    : -
------------------------------------------------------------------------------

     Total UP/DOWN Session Number : 1/0

  3. Associate the BFD sessions with the sub-interfaces.

    # Configure Device A.

    [~DeviceA] bfd pissub 
[*DeviceA-bfd-session-pissub] process-interface-status sub-if
[*DeviceA-bfd-session-pissub] commit
[~DeviceA-bfd-session-pissub] quit

    # Configure Device B.

    [*DeviceB] bfd pissub
[*DeviceB-bfd-session-pissub] process-interface-status sub-if
[*DeviceB-bfd-session-pissub] commit
[~DeviceB-bfd-session-pissub] quit

  4. Verify the configuration.

    # After completing the configuration, run the display bfd session all verbose command on Device A or Device B. The command output shows that Proc Interface Status is Enable (Sub-If). The following example uses the command output on Device A.

    [~DeviceA] display bfd session all verbose
(w): State in WTR  (*): State is invalid
------------------------------------------------------------------------------
  (One Hop)   State : Up                    Name : pissub
------------------------------------------------------------------------------
  Local Discriminator    : 1                Remote Discriminator   : 2
  Session Detect Mode    : Asynchronous Mode Without Echo Function
  BFD Bind Type          : Interface(GigabitEthernet0/1/0)
  Bind Session Type      : Static
  Bind Peer IP Address   : 224.0.0.184
  Bind Interface         : GigabitEthernet0/1/0
  FSM Board Id           : 1                TOS-EXP                : 7
  Min Tx Interval (ms)   : 10               Min Rx Interval (ms)   : 10
  Actual Tx Interval (ms): 10               Actual Rx Interval (ms): 10
  Local Detect Multi     : 3                Detect Interval (ms)   : 30
  Echo Passive           : Disable          Acl Number             : -
  Destination Port       : 3784             TTL                    : 255
  Proc Interface Status  : Enable (Sub-If)Process PST            : Disable
  WTR Interval (ms)      : 0                Config PST             : Disable
  Active Multi           : 3
  Last Local Diagnostic  : Control Detection Time Expired
  Bind Application       : No Application Bind
  Session TX TmrID       : 0                Session Detect TmrID   : 0
  Session Init TmrID     : -                Session WTR TmrID      : -
  Session Echo Tx TmrID  : -
  Session Description    : -
------------------------------------------------------------------------------

     Total UP/DOWN Session Number : 1/0

    # Run the shutdown command on GE 0/1/0 of Device B.

    [~DeviceB] interface gigabitethernet 0/1/0
[~DeviceB-GigabitEthernet0/1/0] shutdown
[*DeviceB-GigabitEthernet0/1/0] commit
[~DeviceB-GigabitEthernet0/1/0] quit

    # Run the display bfd session all verbose and display interface commands on Device A. The command output shows that the BFD session is Down and GE 0/1/0.1 is Up.

    [~DeviceA] display bfd session all verbose
(w): State in WTR  (*): State is invalid
------------------------------------------------------------------------------
  (One Hop)   State : Down                  Name : pissub
------------------------------------------------------------------------------
  Local Discriminator    : 1                Remote Discriminator   : 2
  Session Detect Mode    : Asynchronous Mode Without Echo Function
  BFD Bind Type          : Interface(GigabitEthernet0/1/0)
  Bind Session Type      : Static
  Bind Peer IP Address   : 224.0.0.184
  Bind Interface         : GigabitEthernet0/1/0
  FSM Board Id           : 1                TOS-EXP                : 7
  Min Tx Interval (ms)   : 10               Min Rx Interval (ms)   : 10
  Actual Tx Interval (ms): 10               Actual Rx Interval (ms): 10
  Local Detect Multi     : 3                Detect Interval (ms)   : 30
  Echo Passive           : Disable          Acl Number             : -
  Destination Port       : 3784             TTL                    : 255
  Proc Interface Status  : Enable (Sub-If)  Process PST            : Disable
  WTR Interval (ms)      : 0                Local Demand Mode      : Disable
  Active Multi           : 3
  Last Local Diagnostic  : Control Detection Time Expired
  Bind Application       : No Application Bind
  Session TX TmrID       : 0                Session Detect TmrID   : 0
  Session Init TmrID     : -                Session WTR TmrID      : -
  Session Echo Tx TmrID  : -
  Session Description    : -
------------------------------------------------------------------------------

     Total UP/DOWN Session Number : 0/1
[~DeviceA] display interface gigabitethernet 0/1/0.1
GigabitEthernet0/1/0.1 current state : DOWN (ifindex: 33)
Line protocol current state : DOWN (Main BFD status down)
Last line protocol up time :  2013-07-29 15:39:29
Description: HUAWEI, GigabitEthernet0/1/0.1 Interface
Route Port,The Maximum Transmit Unit is 9600
Internet Address is 10.2.1.1/24
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 00e0-fc12-7890
Last physical up time   :  2013-07-29 15:39:23
Last physical down time : 2013-07-29 15:38:41
Current system time: 2013-07-30 09:15:33
Statistics last cleared:never
      Last 600 seconds input rate: 23513 bits/sec, 2 packets/sec
      Last 600 seconds output rate: 64319 bits/sec, 3 packets/sec
      Input peak rate 26099 bits/sec, Record time: 2013-07-29 15:40:58
      Output peak rate 64809 bits/sec, Record time: 2013-07-30 03:59:41
      Input: 183126871 bytes, 182525 packets 
      Output: 509287017 bytes, 244628 packets
    Input:
      Unicast: 55 packets, Multicast: 160762 packets
      Broadcast: 21708 packets, JumboOctets: 31031 packets
      CRC: 0 packets, Symbol: 0 packets
      Overrun: 0 packets, InRangeLength: 0 packets
      LongPacket: 0 packets, Jabber: 0 packets, Alignment: 0 packets
      Fragment: 0 packets, Undersized Frame: 0 packets
      RxPause: 0 packets
    Output:
      Unicast: 53 packets, Multicast: 243990 packets
      Broadcast: 585 packets, JumboOctets: 0 packets
      Lost: 0 packets, Overflow: 0 packets, Underrun: 0 packets
      System: 0 packets, Overruns: 0 packets
      TxPause: 0 packets

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
#
interface GigabitEthernet0/1/0.1
 undo shutdown
 ip address 10.2.1.1 255.255.255.0
#
bfd pissub bind peer-ip default-ip interface GigabitEthernet0/1/0
 discriminator local 1
 discriminator remote 2
 process-interface-status sub-if
return

  • Device B configuration file

    #
 sysname DeviceB
#
 bfd
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 10.1.1.2 255.255.255.0
#
interface GigabitEthernet0/1/0.1
 undo shutdown
 ip address 10.2.1.2 255.255.255.0
#
bfd pissub bind peer-ip default-ip interface GigabitEthernet0/1/0
 discriminator local 2
 discriminator remote 1
 process-interface-status sub-if
return
Parent Topic: Configuration Examples for BFD
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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