ExtremeSwitching (EXOS)

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LAG sharing packet loss and high latency

  • 1.  LAG sharing packet loss and high latency

    Posted 07-31-2017 17:56
    I have 2 swtiches X670G2-48x-4q, both are working correctly with a LAG (2 ports), version is EXOS 16.1.3.6-patch1-9

    Switch1:

    enable sharing 10 grouping 10,14 algorithm address-based custom lacp

    Switch2:

    enable sharing 2 grouping 2,15 algorithm address-based custom lacp

    When i add a third and fourth link to the LAG in production, like this:

    Switch1:

    Configure sharing 10 add port 37,38

    Switch2:

    Configure sharing 2 add port 9,17

    I can see packets losts and high latency.

    What could be the issue?, should i disable the sharing, and enable it with the new ports?



  • 2.  RE: LAG sharing packet loss and high latency

    Posted 07-31-2017 18:00
    What do you have configured for your custom LACP config?


  • 3.  RE: LAG sharing packet loss and high latency

    Posted 07-31-2017 18:12
    I havent made any change in its configuration, I mean it's configured by default


  • 4.  RE: LAG sharing packet loss and high latency

    Posted 07-31-2017 19:02
    Couple more questions

    Type of traffic running across the links

    What are the current utilization of the 2 port lag

    one gig or ten gig links

    Are those links also a member of others services such as EAPS Spanning Tree ect


  • 5.  RE: LAG sharing packet loss and high latency

    Posted 07-31-2017 20:13
    There are vlans and vmans configured in the links, and we passed video, voice and date traffic. They are ports of TenG, he current utilization is 2.5G aprox in both direction. They're are members of EAPS and EAPS shared-ports.


  • 6.  RE: LAG sharing packet loss and high latency

    Posted 08-01-2017 07:49
    Hi Jhonn,

    Any link errors in the newly added ports?

    "show port rxerrors"
    "show port txerrors"

    Does the "show sharing" indicate that the newly ports are added to aggregation?

    One of the quick remedy i can think of is to take a maintenance window disable and enable the sharing with all intended ports at one go...


  • 7.  RE: LAG sharing packet loss and high latency

    Posted 08-02-2017 21:59
    Hi Kartik, No rxerror nor txerrors. The show sharing shows that the newly ports are added to aggregation. There was congestion on the new port in both sides. About your remedy its necessary to do that in both sides (switches)?


  • 8.  RE: LAG sharing packet loss and high latency

    Posted 08-02-2017 23:53
    Yes, you can try it on both switches. Prior doing it try to execute the command "clear counter" (it will clear the counter stats), then disable and re-enable the sharing. After re-configuring it, check the sharing status and use the command "show lacp counters" to verify the sharing PDU's are exchanged correctly and other parameters are correct.



  • 9.  RE: LAG sharing packet loss and high latency

    Posted 08-03-2017 01:47
    Hi Jhonn,

    Be wary when you are doing these changes.
    First disable the ports and then disable..enable the sharing.



  • 10.  RE: LAG sharing packet loss and high latency

    Posted 08-06-2017 22:59
    Hi all, I work with Jhonn at the same company, and we have disabled the sharing in both sides like you recommended and create it with all 4 ports , but we still had packet loss when the sharing with the 4 ports was formed so we had to disable this two new ports and remove them from the sharing.

    The sharing was formed correctlty

    * MIR-EXT_AGREG.16 # show sharing
    Load Sharing Monitor
    Config Current Agg Min Ld Share Ld Share Agg Link Link Up
    Master Master Control Active Algorithm Group Mbr State Transitions
    ========================================================
    10 10 LACP 1 custom 10 Y A 2
    custom 14 Y A 2
    custom 37 Y A 4
    custom 38 Y A 2


    No txerrrors or rxerrors in new ports, but we noticed again there was congestion increasing in both new ports, in old ports there isnt any congestion. Theres no log that show any signal of what happened.

    Could be a problem of the firmware?


  • 11.  RE: LAG sharing packet loss and high latency

    Posted 08-06-2017 23:16
    I understand the port congestion is still seen. Please refer the below mentioned knowledge base article for your reference:
    https://gtacknowledge.extremenetworks.com/articles/Solution/Prevent-packet-drops

    https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-identifying-microburst-congestion-with-wireshark

    https://gtacknowledge.extremenetworks.com/articles/How_To/How-to-verify-if-the-LACP-PDUs-are-received-from-the-peer-device

    Verify the above provided information and if this issue cannot be isolated. Could you please open a GTAC case to proceed further? So GTAC engineer can troubleshoot the congestion issue via remote session.


  • 12.  RE: LAG sharing packet loss and high latency

    Posted 01-20-2018 15:14
    We have exactly the same problem.
    Was you lucky to find out the cause?


  • 13.  RE: LAG sharing packet loss and high latency

    Posted 01-22-2018 07:24
    Hello, all!

    As Ram mentioned earlier, first of all you have to check microburst in your traffic.
    Also reconfigure shared-packet-buffer on ports (because X670 has 10G ports and as higher the speed of the port, the more the microburst can be present on it).

    Thank you!


  • 14.  RE: LAG sharing packet loss and high latency

    Posted 01-20-2018 15:14
    Hello, Alexander!

    If you has this issue and has valid service contract on your switches, you can wright to your local distributor about that.
    🙂

    Thank you!