IGMP Proxy Bug?

  • Hi there!

    To explain my problem, I will explain my network topology.
    Please note before I start: This has been working succesfully since I bought the Amplifi HD over a month ago.

    I have a 200/200 fiber plan -> Modem/Router from ISP (can't sadly put it into bridge mode, so everything is turned off, especially DHCP and only 1 static address which is the Amp).
    -> Switch 1, port 1: Cat 6 cable from ISP modem to switch
    -> Switch 1, port 2: Cat 6 cable to Switch 2
    -> Switch 1, port 3: Ikea Tradfi (like Philiphs Hue Hub)
    -> Switch 1, port 4: To bed-room wall-outlet -> TV

    Switch 2, port 1: Cat 6 cable from ISP modem.
    Switch 2, port 2: Cat 6 cable to WAN AmpliFi
    Switch 2, port 3,4,5: TV / PS4 / Soundbar
    Switch 2, Port 6: AmpliFi LAN port 1. *

    WAN: to Switch 2, port 1.
    Amp switch, port 1: IPTV
    Amp switch, port 2: to port 6 of Switch 2. *
    *I know this may seen I'm looping my network, but it doesn't, even the Ikea Hub get's an IP address from the Amplifi.

    Note: Both switches are 'non-IMGP snooping'

    My issues:
    Once I installed FW update 2.9.5, the IPTV is eating all the bandwidth on my network. The dials on the AmpliFi's touchscreen, the download goes to 250-280MBPS (while my subscription is 200).

    After a while the network times out, dropping everything and resets itself and going over and over again.
    During the 'bottlekneck', it's impossible to browse the internet, watch tv (stutters).

    What I checked:
    If I remove the Switch 2 'loop', it's fine, looks to me it won't send the Multicast packets anymore.

    I have been in touch with the support of AmpliFi, they will check if it's a bug.
    Per today, I know my 2 switches may need to be IGMP Snooping enabled.

    But it's odd to me that this worked fine for 3.5-4 weeks, until yesterday's update.

    I'm planning to quickly swap the AmpliFi for another Router with the exact same Switch / cable setup and post my results below.

  • Hi @jeroen-osnabrug - you might check wiith @ubnt-brett about the update in Firmware v2.9.5 which included:

    Improved multicast IPTV performance

    Whatever they implemented may not work in your topology

    Firmware v2.9.5 also added a firmware rollback feature to the web portal
    You might want to go back to v2.9.3 until you know what is going on

  • @derek-saville Hi! Thanks for replying.

    I noticed the firmware change log too..

    However, I did the rollback for the Router, not the Mesh points and it didn’t work sadly.
    @UBNT-Brett I hope you can help out. Support (Presila) already received my configuration files.


  • Found the issue, the loop was the problem after all.
    But it's quite odd that it didn't show up since I start using AmpliFi and as said before, I know I was looping the switch but it worked and never showed problems until the FW update to 2.9.5, reverting back to 2.9.3 didn't go back to the working situation, so I guess it was something else..

    The AmpliFi was placed in the living room on the 2nd switch, due the fact I loved the design and the live-speed view.
    Now, working again, it's directly behind in the ISP router in the 'maintenance room' with a closed door.

    I could use Bridge Mode, but I don't want to use the functionalities of the AmpliFi such as Guest Mode.

    Other than that, IGMP is not bugged as I could see the packets in WireShark.

  • If it's looping with a switch you need spanning tree protocol enabled or an option for it.

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