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    [solved] UDP broadcasts

    Scheduled Pinned Locked Moved Firewalling
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    • F
      furom
      last edited by furom

      Hi,

      I see two broadcasts in my log I would like to know more about;

      239.255.255.250:1900 UDP

      Looking it up I find a "Simple Service Discovery Protocol (SSDP)", which seems to be part of UPnP. Should this normally be allowed or how I can determine what it's about?

      I also see

      255.255.255.255:1900 UDP

      which I was not able to google.

      Thanks

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      • R
        rcoleman-netgate Netgate @furom
        last edited by

        @furom 255.255.255.255 is broadcast for any network so that IP is nothing specific.

        239.255.255.250 is a multicast address IIRC.

        UDP1900 brings up this: https://www.grc.com/port_1900.htm

        Ryan
        Repeat, after me: MESH IS THE DEVIL! MESH IS THE DEVIL!
        Requesting firmware for your Netgate device? https://go.netgate.com
        Switching: Mikrotik, Netgear, Extreme
        Wireless: Aruba, Ubiquiti

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        • F
          furom @rcoleman-netgate
          last edited by

          @rcoleman-netgate said in UDP broadcasts:

          @furom 255.255.255.255 is broadcast for any network so that IP is nothing specific.

          239.255.255.250 is a multicast address IIRC.

          UDP1900 brings up this: https://www.grc.com/port_1900.htm

          Thanks! After reading on GRC and also googled "multicast address IIRC", it looks to be local to my network, right? I do get some devices broadcast for something, and is probably all good, but can I be certain this is local to my network(s)? It says "within an organization", so guess it could be interpreted that way?

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          • R
            rcoleman-netgate Netgate @furom
            last edited by

            @furom Multicast is typically always local to your network. Something is sending that out. Open Wireshark and hunt it down. they'll have a MAC you can reference.

            Multicast is also generally unroutable. https://en.wikipedia.org//wiki/Broadcast,_unknown-unicast_and_multicast_traffic

            Ryan
            Repeat, after me: MESH IS THE DEVIL! MESH IS THE DEVIL!
            Requesting firmware for your Netgate device? https://go.netgate.com
            Switching: Mikrotik, Netgear, Extreme
            Wireless: Aruba, Ubiquiti

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