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Aggregated Ethernet Question

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  • 1.  Aggregated Ethernet Question

    Posted 11-23-2018 01:40



    We have two datacentres that are linked together via X-Connectes and 2 x 10gbps ports at each end as an aggregated Ethernet port, forming a 20gbps link. Because of the circuit we have running between the sites (supplied by external cabling supplier) it is causing us a problem with X-Connect, full site redundancy.


    Here is the X-Connect topology:


    Site A Core - ae1 ---- X-Connect equipment A <--------------------> X-Connect equipment B ---- ae1 - Site B Core


    X-Connect equipment Site A: 2 x BT Equipment - For fiber end point 

    X-Connect equipment Site B: 2 x BT Equipment - for fiber end point


    We then patch from the two aggregated ports to each separate X-Connect device. So the toppolgy from a Site perspective is:


    Site A:

    Core xe-1/1/1 -----> X-Connect Equipment -------------------- X-Connect Equipment Site B ------- Core xe-1/1/1

    Core xe-1/1/2 -----> X-Connect equipment -------------------- X-Connect Equipment Site B ------- Core xe-1/1/2


    Because the X-Connect equipment is self powered it supplies it's own sense to the other site X-Connect equipment.


    So the problem with that is as follows:


    If we lose one sfp or a fibre patch between the Core port and the X-Connect equipment, then that site will drop to 10gbps, but it will only be sensed to the X-Connect equipment. The other site still senses that it's connections to X-Connect equipment is UP and therefore remains at 20gbps. This means the aggregated link actually fails completely. There is NO problem at all if the X-Connect equipment fails because the other side X-connect equipment will sense it. The problem will only happen if we have a failure of an sfp or patch cable etc....... The curernt workaround is monitoring those links carefully and then dropping the opposing port to keep the ae1 link up. This resolution is not good for moving forwards.


    This is an unfortunate scenario because of the type of circuit.


    Question: Is there a way, on an aggregated link, that a heartbeat can run from end-to-end to sense if a link has gone down?


    As I mentioned, curerntly, it only senses to the X-Connect equipment and I need some way of sensing across the whole link.






  • 2.  RE: Aggregated Ethernet Question
    Best Answer

    Posted 11-23-2018 02:05

    what about enabling LACP on ae links? or is it already enabled and not working as expected?

  • 3.  RE: Aggregated Ethernet Question

    Posted 11-23-2018 03:32

    Hi Nellika


    Didn't think of that. Good shout. I'll configure it up and test and let you know the results.



  • 4.  RE: Aggregated Ethernet Question

    Posted 11-23-2018 08:30

    Yep. Don't know why LACP slipped my mind.


    That's worked perfectly. Cheers.