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Viewing 7 posts - 1 through 7 (of 7 total)
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  • July 27, 2020 at 10:46 pm #28471
    Marius Paulauskas
    Participant

    Has anyone successfully connected A3 Ethernet variant to enterprise class network switch such as Cisco 2960S or 2960X? No matter what I do A3 only establishes link for split second and then reboots. I don’t see any frames coming out of it and no MAC address in switch CAM table.
    I tried everything possible like setting port into auto negotiation or tried all combinations of speed and dupplex, disabled all “smart” features like spanning tree and such but nothing works. Also tried power supply of higher voltage.
    A3 does work however if it is connected to home network type of switch which proofs unit itself is fine.

    July 29, 2020 at 11:54 am #28474
    Wolferl
    Moderator

    Just guessing….maybe there is firewall enabled in that switch?
    Also try to enable all 10/100/1000M modes.

    July 29, 2020 at 3:32 pm #28475
    Marius Paulauskas
    Participant

    It has nothing to do with firewalls if link is not being negotiated.
    and what do you mean by “enable all 10/100/1000M modes”? It auto-negotiates speed/duplex but I also tried forcing manually – nothing worked.

    August 1, 2020 at 10:41 pm #28478
    Ken Jamrogowicz
    Participant

    I would like to explain my suggestion to add a length of cable between the A3 and the “enterprise class” switch. I have observed that some of the commercial switches that are designed to comfortably drive 1000M through 100m of cable are producing a rather powerful transmit signal. If you connect that to an Ethernet interface that is designed for “hobby” type application, the little transformers in the adapter can get saturated and make garbage out of the signal that the micro sees. The conclusion would be that this is not a valid network. It might barely work, if you force the connection to 10M because then you have some nanoseconds for the transformers to come out of saturation. But not for all data strings. Inserting a length of lossy cable between the switch and the A3 would ameliorate this particular problem (if it is the problem).

    Ken

    August 24, 2020 at 7:53 pm #28500
    uRADMonitor
    Keymaster

    @ke2n this is a very interesting suggestion. Another solution was to provision the A3’s with Static IP settings to match the network it is being used in.

    This works perfectly, so perhaps the problem is a different one, rather related to some DHCP issues?

    August 24, 2020 at 9:04 pm #28509
    Ken Jamrogowicz
    Participant

    Quite some time ago I changed my router to supply a static connection for the uRad monitor, but it obviously has not helped my particular unit.
    = =
    The problem at the top of this chain of notes was one of the unit having trouble recognizing that it had a valid PHY connection. So – quite a bit before the issue of DHCP comes up. I actually ran into this sort of problem with an earthquake sensor that I run here. Until I added the extra length of cable, there was all kind of noise on the earthquake signal. This only happened when it was connected to a gigabit switch rated for 100 meters of cable …

    April 21, 2021 at 7:09 am #28832
    Scott McInness
    Participant

    @mpaulauskas were you able to resolve this issue? I’m having the same experience with a Model A 3.4, which has worked fine connected to an 8-port switch module in a Cisco 1941W for five years but doesn’t work on a 2960S. I have an A3 (wired) at work, which works on a 2960-X (with about 25m of structured cable) and also a 6509 (1m patch lead).

    The interface comes up for ~15 seconds and then goes down and, as you observed, no MAC address appears in the CAM table. The Ethernet controller in the A seems to lock up at that point, since leaving it powered and connecting it back to the 1941 results in the interface still not coming up. Power-cycling the A returns it to normal operation.

    Interestingly, if the A is booted whilst connected to the 1941 and I re-patch it to the 2960S it works fine. Booting it whilst not connected to anything results in a locked-up Ethernet controller after ~15 seconds, which requires power-cycling to rectify.

    The A is the only thing left connected to the 1941, which is being retired since I have a new firewall, it’s old, doesn’t have enough ports, and also no longer need the ADSL capability. I have a wireless A3 at home, as well, so I may just end up retiring the Model A.

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