Wireless Access

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  • 1.  Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago

    I have a large fleet of Aruba 501 radios and I have noticed that I get about 200 FCS errors a second. I pulled a PCAP from the device and I have observed tons of malformed packet messages to almost all beacon frame messages. The beacon interval on the access point side is 100ms and we have about 8 SSIDs per access point and the density of access points is high so we will see a lot of this traffic. I am finding that this seems to cause issues with the device roaming correctly. I have another model of radio which when I pull these PCAPs I do not have the same errors. I tried to get help from support but because the 501 is EOL/EOS all I can do is RMA them. 

    Frame 141: 434 bytes on wire (3472 bits), 434 bytes captured (3472 bits)
    Radiotap Header v0, Length 25
    802.11 radio information
    IEEE 802.11 Beacon frame, Flags: ........
    IEEE 802.11 Wireless Management
    [Malformed Packet: IEEE 802.11: length of contained item exceeds length of containing item]
        [Expert Info (Error/Malformed): Malformed Packet (Exception occurred)]

    Frame 162: 365 bytes on wire (2920 bits), 365 bytes captured (2920 bits)
    Radiotap Header v0, Length 25
    802.11 radio information
    IEEE 802.11 Beacon frame, Flags: ........
    IEEE 802.11 Wireless Management
    [Malformed Packet: IEEE 802.11]
        [Expert Info (Error/Malformed): Malformed Packet (Exception occurred)]
            [Malformed Packet (Exception occurred)]
            [Severity level: Error]
            [Group: Malformed]



  • 2.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago

    If you have 8 BSSIDs per radio and especially in high-density, it's expected that you see a lot of errored packets. Some/most radios just discard those packets, so that you don't see them on other devices doesn't mean that they are not there. From the captures that you have, you may check in the header fields on which channel, at what signal strength and from which AP you see the most of these errors.

    Where did you create these captures from? Is it the 501 bridge itself? If you have an external capturing device the location of that device would be important as well if you use multiple spacial streams (MIMO), but for beacons that should not be an issue as these go out in a single stream.

    In high density, I would not go above 2 or 3 SSIDs per radio. Optimizing your RF/SSID planning would be recommended regardless what you see here.

    Did you check the channel utilization/noise-level already?

    More important, do you see a significant performance degradation on the 501 versus the other client? Still the busy RF environment may be the reason, but would be good to know.



    ------------------------------
    Herman Robers
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    If you have urgent issues, always contact your HPE Aruba Networking partner, distributor, or Aruba TAC Support. Check https://www.arubanetworks.com/support-services/contact-support/ for how to contact HPE Aruba Networking TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or HPE Aruba Networking.

    In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
    ------------------------------



  • 3.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago
    Edited by mfk 11 days ago

    I don't think the amount of BSSIDs is a problem. The network is well tuned we are only using 20mhz and the channels are very spread out from an RF standpoint. The Aruba 501 is the only device we see 200 FCS errors a second on. The PCAPs are always from the device we are evaluating. In terms of performance there's about a 8-9db difference between the clients as they move through the network. When I've adjusted the thresholds to hopefully pull the devices more in line with the rest of the wireless clients, I do not see much improvement. My hypothesis is that because there are so many bad beacon frames that the device is not roaming appropriately. We have to run relatively old firmware because the latest does not work on the network at all. 

    To give you an idea, this is about what every beacon frame looks like. Almost all of them report as malformed. 




  • 4.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago

    What version of firmware are you running on the 501?



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    Carson Hulcher, ACEX#110
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  • 5.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago

    We've found that 0027 is the most "stable" but that's not really saying much. When we've tried to use 0030 but it has been very problematic. I reported a bug about SNMPv3 that was fixed even though the device was EOL/EOS and that firmware was 0032 but it was problematic as well. 




  • 6.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago

    Have you tried 0033?

    And yes, the product is very EOL.



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    Carson Hulcher, ACEX#110
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  • 7.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago

    33 is what I meant not 32.




  • 8.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago

    Problematic in what way?  Was a ticket opened on that?



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    Carson Hulcher, ACEX#110
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  • 9.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 11 days ago

    It won't stay connected to the network. It's almost like it tries to roam constantly. The device doesn't stay on the network long enough for me to get data from it remotely. Any time I try to open tickets I am met with "This device is EOL/EOS and there's nothing we can do but RMA it." 




  • 10.  RE: Aruba 501 Beacon Frame Malformed Packets Messages

    Posted 10 days ago
    Edited by jhoward 10 days ago

    Hey mfk, if you could email me at jerrod.howard@hpe.com we would like to connect and likely get another ticket open so engineering can look at the pcaps to see the malformed frames and if it can be or is seen to be reprouced. And if you have a TAC case please include in the email and if not we likely want to get one up so the team can start looking. We DO have support in SW for active support contracts, even if the HW is EoL as it's still suported (for major bugs but no new features).