Description

The article explains the issue when issuing the command "show pfe filter hw summary" on ACX5448 routers, then BFD for bundle interfaces will sometimes fail causing a flap of the bundle interface.

 

Symptoms

Customer had noticed that issuing the command "show pfe filter hw summay" on their ACX5448

The BFD session flaps for a small fraction.
 

labroot@RE15# run show pfe filter hw summary | no-more       

Jun 26 00:07:21

Slot 0 

  ================================================================

    Active Firewall Feature Profile is : default

  ================================================================

 

INT-TCAM-BANK IN-USE WIDTH ENT-FREE ENT-MAX  DIR HW-OWNER  NUM-GRP

============= ====== ===== ======== =======  === ========  =======

0\1      Yes   320b  1950   2048   ING pmf-0    2

2\3      Yes   320b  2047   2048   ING pmf-1    1

4       No   160b  2048   2048   NA  NA     0

5       No   160b  2048   2048   NA  NA     0

6       No   160b  2048   2048   NA  NA     0

7       No   160b  2048   2048   NA  NA     0

8       No   160b  2048   2048   NA  NA     0

9       No   160b  2048   2048   NA  NA     0

10       No   160b  2048   2048   NA  NA     0

11       No   160b  2048   2048   NA  NA     0

12\13     Yes   320b  106    128    ING pmf-0    1

14       Yes   160b  116    128    ING pmf-0    1

15       No   160b  128    128    NA  NA     0

 

INT-TCAM-BANK  NUM-GRP

 

[edit]

labroot@RE15# run show bfd session address 172.16.1.2 extensive   

Jun 26 00:06:21

                         Detect  Transmit

Address         State   Interface   Time   Interval Multiplier

172.16.1.2        Up    xe-0/0/3    0.450   0.150    3  

 Client LACPD, TX interval 0.150, RX interval 0.150

 Session up time 00:02:28. ---------------------------------------------------------------- <<

 Local diagnostic None, remote diagnostic None

 Remote state Up, version 1

 Session type: Micro BFD

 Min async interval 0.150, min slow interval 1.000

 Adaptive async TX interval 0.150, RX interval 0.150

 Local min TX interval 0.150, minimum RX interval 0.150, multiplier 3

 Remote min TX interval 0.150, min RX interval 0.150, multiplier 3

 Local discriminator 20, remote discriminator 21

 Echo TX interval 0.000, echo detection interval 0.000

 Echo mode disabled/inactive

 Remote is control-plane independent

 Session ID: 0

 

 

Solution

On the above issue configuring BFD minimum-interval to 500ms resolves the issue

Modification History

2024-07-31 : Article Created