Wired Intelligent Edge

 View Only
last person joined: 10 hours ago 

Bring performance and reliability to your network with the Aruba Core, Aggregation, and Access layer switches. Discuss the latest features and functionality of the ArubaOS-Switch and ArubaOS-CX devices, and find ways to improve security across your network to bring together a mobile first solution.
Expand all | Collapse all

uplink between 2 Aruba switches starves from bpdu

This thread has been viewed 37 times
  • 1.  uplink between 2 Aruba switches starves from bpdu

    Posted Jan 17, 2022 06:49 AM
    Hi all,
    in one of our sites, I'm having trouble getting an uplink working. Here's the situation:
    The main switch is an aruba 2540.
    One of the switches connected to it, is an Aruba 2930F 8-ports.
    Both switches run on version 16.10.0016.

    When this 8-ports switch is connected to the 2540, the ports go down (=no link, leds out). It's not a bpdu protection thing, because they don't go "admin down" and there is no bpdu protection on any of these uplink ports - I checked that 100 times or so, also in the logs this is not there.


    Here's the port config of the 8-ports switch:
    interface 8
       broadcast-limit 10
       tagged vlan 40,42-44,46-47
       untagged vlan 1
       loop-protect
       exit
    ​

    Here's the port config of the 2540 switch:
    interface 11
       name "lab"
       tagged vlan 40,42-44,46-47
       untagged vlan 1
       loop-protect
       exit
    ​​

    When an unmanaged switch is connected in between the 2 Aruba's, all works like a charm.
    None the other switches have this problem. I used a template - pushed by Airwave - to put the initial config on all switches in that site, so there should be no difference there - except for the vlans per port of course.

    In the logs of the 2540, I just see port up/down, nothing more
    In the logs of the 8-ports, I see a message for all vlans that they "Starved for a BPDU on port 8 from Desginated Bridge"

    I tried the below already:
     - use another port (on both switches)
     - I asked our local guy to disconnect everything from the 8-ports switch and only connect the uplink
     - disabled/enabled spanning tree
     - removed spanning tree mode (rapid pvst)
     - rebooted switch
     - configured keep-alives on the uplink ports (tried on each side)
     - bpdu filter
     - broadcast limit
     - ...
    Nothing of the above worked

    I'm out of ideas to try to get this working. Does anybody of you have more inspiration for me on this, please?

    Thanks!


  • 2.  RE: uplink between 2 Aruba switches starves from bpdu

    EMPLOYEE
    Posted Jan 17, 2022 08:39 AM
    Hi,

    Without diving into the details you've shared, I will advise you to try without loop-protect. It is mentioned in the documentation as well, that loop-protect should not be used for uplinks. Normally it is used for downstream switches that do not run spanning tree.
    Could you please disable loop-protect and share the results? 

    Thank you!

    ------------------------------
    Stanislav Naydenov
    ------------------------------



  • 3.  RE: uplink between 2 Aruba switches starves from bpdu

    MVP GURU
    Posted Jan 17, 2022 04:48 PM
    Hi! in addition to what Stanislav already suggested you, set both uplink interfaces with the spanning tree option "point-to-point-mac" with "true" (spanning-tree <port-list|port-range|port-id> point-to-point-mac [ true | false | auto ]) reserved for switch-to-switch inter-links (true =  indicates a point-to-point link to a device such as a switch, bridge, or end-node).





  • 4.  RE: uplink between 2 Aruba switches starves from bpdu

    Posted Jan 19, 2022 06:15 AM
    Hi,
    thanks for your replies!
    I could only continue testing today as our local IT guy was working from home yesterday.
    I tried both of your suggestions, however nothing helped. 
    Also if I configure the spanning-tree point-to-point-mac as true, it doesn't show in the running config, so I guess that's the default value?

    What we did today: swap the "non-working" switch with another one that was working fine => problem stayed in the problem location (=non working switch started working and the working switch stopped working).
    So we swapped the uplink cables and the problem moved with the cable.
    There were no errors at none of the 2 sides of the cable (checked both the main switch and the 8-ports switch) => we used another uplink cable anyway and that solved the problem...

    I really don't understand why an unmanaged switch works and a managed switch doesn't work with that uplink cable

    In any case, the problem looks to be solved. Let's hope it stays ok now *fingerscrossed*


  • 5.  RE: uplink between 2 Aruba switches starves from bpdu

    MVP GURU
    Posted Jan 21, 2022 09:44 AM
    Hi, so - just to be clear - has the issue gone away by just swapping the cable used on for the uplink with another one?

    ------------------------------
    Davide Poletto
    ------------------------------



  • 6.  RE: uplink between 2 Aruba switches starves from bpdu

    Posted Jan 24, 2022 02:54 AM
    Hi,
    that is correct.
    Strange thing is that there were no CRC errors or any kind of other errors shown on the uplink ports.