ExtremeSwitching (EXOS)

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Auto-edge vs ezspantree

  • 1.  Auto-edge vs ezspantree

    Posted 11-23-2018 08:46
    So I had a problem where a 5x X440-G2 stack with 75 iMacs on it would drop packets when the iMacs booted up, some investigation pointed the finger at spanning-tree, once I configured the ports with link-type edge the problem went away. My question now is why did I have to do this manually? auto-edge is supposed to be on by default, but show s0 ports detail shows Operational Edge : FALSE whether or not I have configured auto-edge on for that port. I have auto-bind on for all VLANs, and ezspantree enabled too.

    I found this post which seems similar to what I'm seeing

    I'm running ( was quite crashy).

  • 2.  RE: Auto-edge vs ezspantree

    Posted 11-24-2018 22:09
    Can you show the output of "show conf stp"?

  • 3.  RE: Auto-edge vs ezspantree

    Posted 11-24-2018 22:09
    It's very straightforward:

    enable stpd s0 auto-bind vlan AV
    repeated for each VLAN. And since the GTAC case, lots of this for the ports with iMacs:
    configure stpd s0 ports link-type edge 1:24

    Nothing else. For some reason I don't have ezspantree enabled on this stack, that's a bit weird since I thought I had it on all stacks. Although on the stacks that do, they just have the auto-bind commands as well. Their ports are also Operational Edge: FALSE, Auto Edge: On.

  • 4.  RE: Auto-edge vs ezspantree

    Posted 11-26-2018 11:52
    Hm, a while ago I played around with Auto Edge, and it did work as advertised. I do not remember which EXOS version.

    Please note that Auto Edge will wait a few seconds before calling a port an edge port, and the port loses that state when it goes down. Manually configuring an edge port will place it into forwarding immediately.

    It is quite dangerous to use an edge port on EXOS without edge-safeguard, because without edge-safeguard the port will not originate BPDUs and thus will not detect loops over two edge ports.


  • 5.  RE: Auto-edge vs ezspantree

    Posted 11-26-2018 11:52
    Hmm, that's a bit of a concern since auto-edge is enabled by default and edge-safeguard is disabled by default. Either way perhaps there is a bug per the final comment in the post I linked.

    Really I just want it to all just work like it did on EOS without me having to configure anything. Sensible defaults anyone?

  • 6.  RE: Auto-edge vs ezspantree

    Posted 11-26-2018 11:52
    Not really a concern, since Auto Edge designated OperEdge ports work like they did on EOS, i.e. they do generate BPDUs.

    Exactly your concern raised by a colleague made me take a look at this then new to EXOS feature.

  • 7.  RE: Auto-edge vs ezspantree

    Posted 11-26-2018 11:52
    I am currently wondering:
    1) When for example both loop-protect and auto-edge are enabled, how does the switch determine whether it should go into forwarding state or not?
    2) Does auto-edge still do something when link-type is not set to auto?

  • 8.  RE: Auto-edge vs ezspantree

    Posted 11-26-2018 11:52
    I did not test any of those combinations.

  • 9.  RE: Auto-edge vs ezspantree

    Posted 11-26-2018 11:52
    How did you discover Auto Edge designated OperEdge ports send BPDUs? Is it documented anywhere? I had a look and couldn't find anything.

    Also I just realised the feature I really want is to not have a lot of topology changes when the lab boots up. Does Auto Edge cause topology events for link up/down events when no BPDUs are detected on the port?

  • 10.  RE: Auto-edge vs ezspantree

    Posted 11-26-2018 11:52
    I used Wireshark to check if BPDUs were sent.

    I did not check if TCNs were generated if Auto Edge decided to place a port into Oper Edge state. I would configure STP edge ports (w/safeguard) for ports that are supposed to be edge ports instead of relying on Auto Edge (this is true for both EOS and EXOS).

  • 11.  RE: Auto-edge vs ezspantree

    Posted 11-26-2018 13:27
    I found https://gtacknowledge.extremenetworks.com/articles/Solution/STP-Topology-Changes-are-generated-even-... but xos0070993 is listed as fixed in 22.5.1 so that's not it. Maybe there's another bug lurking?

    Also 22.6.1-Patch1-1 (which has release notes but no software available) has as its only fix xos0073370 ExtremeSwitching X440-G2 and X620 series switches are not stable when used in a stack.

  • 12.  RE: Auto-edge vs ezspantree

    Posted 11-30-2018 13:59
    I found a few ports are being marked as Operational Edge by Auto Edge, but it's far fewer than I would have thought.

  • 13.  RE: Auto-edge vs ezspantree

    Posted 12-03-2018 21:30

    22.6.1-Patch1-1 was finally posted to the portal today. Here's a link to the X440-G2 product page where you can download it: https://extremeportal.force.com/ExtrProductDetail?id=01t34000003vzmbAAA