SSDP blast?

Help and support for HDHomeRun DVR and HDHomeRun software for Windows 10, Mac, Android, XBox, etc.
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pfile
Posts: 20
Joined: Tue Jan 10, 2006 7:48 pm

SSDP blast?

Post by pfile » Wed Jul 03, 2019 10:10 pm

a couple of times i've noticed one or both of my HDTC-2US blasting UDP packets from source port 1900 to dest port 5914 at kind of a martian address on my network for minutes at a time, then stopping. i never was able to do a tcpdump while it was happening, but my firewall was logging these packets (and forwarding them out to the internet.)

port 1900 is supposedly assigned to SSDP. whats confusing about this is that SSDP is supposed to use an IP multicast packet but what i was seeing were (i think) unicast packets. the martian address, it turns out, belongs to one of my machines for which i had assigned a 2nd IP address on a different subnet. i had needed that to test some other networking equipment and forgotten to remove it.

i'm wondering if you guys know what may be going on here. could this be a bug in the UPnP stuff? it is odd that the HDHR seems to have honed in on a machine with a martian address. as an aside, the total data rate was in the 2mbit/sec.

thanks for any insight.

nickk
Silicondust
Posts: 15523
Joined: Tue Jan 13, 2004 9:39 am

Re: SSDP blast?

Post by nickk » Thu Jul 04, 2019 10:02 am

Packets from source port 1900 on the HDHomeRun to a unicast IP with a different port number - that is a SSDP reply sent is response to a SSDP request by the remote system.

Nick

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