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PTX router automatically uses remaining PFEs to route traffic if one of them dies?

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  • 1.  PTX router automatically uses remaining PFEs to route traffic if one of them dies?

    Posted 02-10-2020 22:31

    Hi, 

    If I disable one of the PFEs, will PTX router use the remaining PFEs to route traffic. I think it does, just want some confirmation.

     

    P



  • 2.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?

     
    Posted 02-10-2020 22:40

    What is the FPC type?

     

    tks,

    Abhishek



  • 3.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?

    Posted 02-11-2020 14:49

    @Abhishek: The FPC type is JNP10001-36MR-PIC as seen below:

     

    show chassis pic pic-slot 0 fpc-slot 0

     

    FPC slot 0, PIC slot 0 information:

      Type                             JNP10001-36MR-PIC



  • 4.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?

     
    Posted 02-10-2020 22:51

    In general if a pfe is disabled (which happens sometimes due to fabric error or any other reason) the other pfes will work as expected.



  • 5.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?

     
    Posted 02-10-2020 22:56

    You can check the pfe state with the following command

     

    labroot@Switch> show chassis fpc errors
    FPC Level Occurred Cleared Threshold Action-Taken Action
    0 Minor 0 0 10 0 LOG|
    Major 0 0 1 0 CM ALARM|
    Fatal 4 0 1 4 CM ALARM|
    Pfe-State: pfe-0 -ENABLED | pfe-1 -ENABLED | pfe-2 -ENABLED |

     

    So if pfe-0 is disabled the other pfe, pfe-1 and pfe-2 shall function as expected



  • 6.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?

     
    Posted 02-11-2020 10:44

    Hi,

     

    First you need to make sure all your ECMP path has member across different PFEs, either ae bundle or parallel links 

    Second, in most cases of single PFE failure, system will disable the PFE by disabling the WAN link. By protocol convergence, traffic is routed to other PFEs 

     

    Hope this has addressed your concern 



  • 7.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?

    Posted 02-12-2020 17:15

    @mhu:

    How can I verify that ECMP path has members across different PFEs?  Thanks.

     

    P



  • 8.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?
    Best Answer

     
    Posted 02-12-2020 18:16

    Hi Pluu,

    If one PFE wedges or doesn't function for some reason others will continue to function. Whether or not those PFE route traffic  totally depend on your network design.

    You need to design your IP network in a way so that you have ECMP and your forwarding next-hops are on more than one PFE.

     

    Here are some example and theory for your reference:

    https://www.juniper.net/documentation/en_US/junos/topics/topic-map/ecmp-flow-based.html <<< this is for srx but concept remains same


    https://www.juniper.net/documentation/en_US/junos/topics/usage-guidelines/policy-configuring-per-packet-load-balancing.html

    PS: Please accept my response as solution if it answers your query, kudos are appreicated too!

    Thanks
    Vishal



  • 9.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?

    Posted 02-12-2020 22:35

    Hi ,

     

    below documnet tells you the mapping of interface to the PFE for EX switches :

     

    https://kb.juniper.net/InfoCenter/index?page=content&id=KB10963

     

    For PTX I believe you will be able to get on the hardware 

    for ECMP you need to have multiple ports connected to the same device probably at RTG or trunking which will ensure stable communication even incase of PFE failure 

     

    Regards ,

    Sharanya 



  • 10.  RE: PTX router automatically uses remaining PFEs to route traffic if one of them dies?

    Posted 02-12-2020 22:37