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  • 1.  Bandwidth issue on QFX5100-48S-6Q and HP ProLiant DL380 Gen10 Servers.

    Posted 04-12-2022 11:06
    Hi people,

    I need help with my issue, I have a pair of "QFX5100-48S-6Q" in a Virtual-Chassis, so when I connect my two "HP ProLiant DL380 Gen10 " servers directly to each other and run iperf,
    I get full 10Gb/s throughput. But when I connect these servers via a pair of QFX5100 on same VLAN, throughput is capped to 6Mb/s.  Below is a configuration of the ports in QFX5100 where I connect the servers.

    set interfaces xe-0/0/0 mtu 9214
    set interfaces xe-0/0/0 unit 0 description SERVER1
    set interfaces xe-0/0/0 unit 0 family ethernet-switching interface-mode access
    set interfaces xe-0/0/0 unit 0 family ethernet-switching vlan members VLAN100

    set interfaces xe-0/0/1 mtu 9214
    set interfaces xe-0/0/1 unit 0 description SERVER2
    set interfaces xe-0/0/1 unit 0 family ethernet-switching interface-mode access
    set interfaces xe-0/0/1 unit 0 family ethernet-switching vlan members VLAN100

     The switches are running Junos: 18.1R3-S6.1, has anyone ever encounter something like this?  

    Thanks,

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    HONGERA NGERAGEZA
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  • 2.  RE: Bandwidth issue on QFX5100-48S-6Q and HP ProLiant DL380 Gen10 Servers.

    Posted 04-13-2022 17:17
    Hongera,

    Your performance issue could be created by flow-control, where the QFX5100 slows down due to receiving MAC pause frames from the server.  I was able to fix slow server performance in a Data Center with

    set interface xe-0/0/0 ether-options no-flow-control
    set interface xe-0/0/1 ether-options no-flow-control
    commit comment "disable flow-control for iperf testing"


    You can see if flow-control is enabled, and whether you have any MAC pause frames with "show interface extensive".  I would look at the interface stats before and after you make the change.

    Hope this helps.
    Tim Brown
    tim.brown at CopperRiverTech dot com

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    TIM BROWN
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    Original Message


  • 3.  RE: Bandwidth issue on QFX5100-48S-6Q and HP ProLiant DL380 Gen10 Servers.

    Posted 06-10-2022 09:36
    Thanks for the contribution Tim, however I found the solution. I had to disable DCBX protocol that was enabled for all ports and the problem went away.

    delete protocols dcbx
    commit comment "disabling dcbx" and-quit

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    HONGERA NGERAGEZA
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    Original Message