Technical Documentation

Configuring BFD Authentication for IS-IS

Beginning with JUNOS Release 9.6, you can configure authentication for BFD sessions running over IS-IS. Routing instances are also supported. Only three steps are needed to configure authentication on a BFD session:

  1. Specify the BFD authentication algorithm for the IS-IS protocol.
  2. Associate the authentication keychain with the IS-IS protocol.
  3. Configure the related security authentication keychain.

The following sections provide instructions for configuring and viewing BFD authentication on IS-IS:

Configuring BFD Authentication Parameters

To configure BFD authentication:

  1. Specify the algorithm (keyed-md5, keyed-sha-1, meticulous-keyed-md5, meticulous-keyed-sha-1, or simple-password) to use for BFD authentication on an IS-IS route or routing instance.
    [edit]user@host# set protocols isis interface if1-isis bfd-liveness-detection authentication algorithm keyed-sha-1

    Note: Nonstop active routing (NSR) is not supported with meticulous-keyed-md5 and meticulous-keyed-sha-1 authentication algorithms. BFD sessions using these algorithms may go down after a switchover.

  2. Specify the keychain to be used to associate BFD sessions on the specified IS-IS route or routing instance with the unique security authentication keychain attributes. This should match the keychain name configured at the [edit security authentication key-chains] hierarchy level.
    [edit]user@host# set protocols isis interface if1-isis bfd-liveness-detection authentication keychain bfd-isis

    Note: The algorithm and keychain must be configured on both ends of the BFD session, and they must match. Any mismatch in configuration prevents the BFD session from being created.

  3. Specify the unique security authentication information for BFD sessions:
    • The matching key-chain-name as specified in step 2.
    • At least one key, a unique integer between 0 and 63. Creating multiple keys allows multiple clients to use the BFD session.
    • The secret-data used to allow access to the session.
    • The time at which the authentication key becomes active, yyyy-mm-dd.hh:mm:ss.
    [edit security]user@host# authentication-key-chains key-chain bfd-sr4 key 53 secret $9$ggaJDmPQ6/tJgF/AtREVsyPsnCtUHm start-time 2009-06-14.10:00:00
  4. (Optional) Specify loose authentication checking if you are transitioning from nonauthenticated sessions to authenticated sessions.
    [edit]user@host> set protocols isis interface if1-isis bfd-liveness-detection authentication loose-check
  5. (Optional) View your configuration using the show bfd session detail or show bfd session extensive command.
  6. Repeat these steps to configure the other end of the BFD session.

Note: BFD authentication is only supported in the domestic image and is not available in the export image.

Viewing Authentication Information for BFD Sessions

You can view the existing BFD authentication configuration using the show bfd session detail and show bfd session extensive commands.

The following example shows BFD authentication configured for the if1-isis interface. It specifies the keyed SHA-1 authentication algorithm and a keychain name of bfd-isis. The authentication keychain is configured with two keys. Key 1 contains the secret data “$9$ggaJDmPQ6/tJgF/AtREVsyPsnCtUHm” and a start time of June 1, 2009, at 9:46:02 AM PST. Key 2 contains the secret data “$9$a5jiKW9l.reP38ny.TszF2/9” and a start time of June 1, 2009, at 3:29:20 PM PST.

[edit protocols isis]interface if1-isis {bfd-liveness-detection {authentication {algorithm keyed-sha-1;key-chain bfd-isis;}}}[edit security]authentication key-chains {key-chain bfd-isis {key 1 {secret “$9$ggaJDmPQ6/tJgF/AtREVsyPsnCtUHm”;start-time “2009-6-1.09:46:02 -0700”;}key 2 {secret “$9$a5jiKW9l.reP38ny.TszF2/9”;start-time “2009-6-1.15:29:20 -0700”;}}}

If you commit these updates to your configuration, you would see output similar to the following. In the output for the show bfd sessions detail command, Authenticate is displayed to indicate that BFD authentication is configured. For more information about the configuration, use the show bfd sessions extensive command. The output for this command provides the keychain name, the authentication algorithm and mode for each client in the session, and the overall BFD authentication configuration status, keychain name, and authentication algorithm and mode.

show bfd sessions detail

user@host# show bfd session detail 

                                                  Detect   Transmit
Address                  State     Interface      Time     Interval  Multiplier
10.9.1.29                 Up        ge-4/0/0.0     0.600     0.200        3   
 Client ISIS L2, TX interval 0.200, RX interval 0.200, multiplier 3, Authenticate 
 Session up time 3d 00:34, previous down time 00:00:01
 Local diagnostic NbrSignal, remote diagnostic AdminDown
 Remote state Up, version 1
 
1 sessions, 1 clients
Cumulative transmit rate 10.0 pps, cumulative receive rate 10.0 pps

show bfd sessions extensive

user@host# show bfd session extensive    
                                                  Detect   Transmit
Address                  State     Interface      Time     Interval  Multiplier
10.9.1.29            Up        ge-4/0/0.0          0.600     0.200      3
  Client ISIS L2, TX interval 0.200, RX interval 0.200, multiplier 3, Authenticate 
        keychain bfd-isis, algo keyed-sha-1, mode strict   
  Session up time 00:04:42
 Local diagnostic None, remote diagnostic NbrSignal
 Remote state Up, version 1
 Replicated 
 Min async interval 0.300, min slow interval 1.000
 Adaptive async TX interval 0.300, RX interval 0.300
 Local min TX interval 0.300, minimum RX interval 0.300, multiplier 3
 Remote min TX interval 0.300, min RX interval 0.300, multiplier 3
 Local discriminator 2, remote discriminator 2
 Echo mode disabled/inactive
 Authentication enabled/active, keychain bfd-isis, algo keyed-sha-1, mode strict  

1 sessions, 1 clients

Cumulative transmit rate 10.0 pps, cumulative receive rate 10.0 pps

Published: 2010-04-14