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Co-existence of IGMP and SSDP on Windows XP Network Stack RRS feed

  • Question

  • Hello,

    I am posting the question on Network stack here since I didn't find an answer in the Winsock forum.

    I have two Win XP machines talking to each other over a WiFi link. (not a windows zero config network). Now I have written an UPnP application that runs on the WiFi device (source) which is connected to machine 1. It periodically sends out SSDP advertisements to the multicast group address 239.255.255.250. The machine 2 (client), on seeing these SSDP announcements learns of the UPnP capable device (which is the source WiFi device) and shows it in the 'My Network Places' when I click on the 'Show Icons for networked UPnP devices' on the left hand pane. Everything was working as expected but there was a weird thing happening. 

    For some reason the client machine's Win XP is sending out IGMP v3 membership reports to join the address 239.255.255.250. I saw this using Wireshark on the same machine. Now the problem is that I also have IGMP snooping code running on my source WiFi device that is connected to the machine 1. The device on seeing the IGMP v3 reports from the other machine tries to add it to its database which is not the behaviour I wanted. I want to keep SSDP separate from IGMP and this behaviour of XP sabotages my system's behaviour. 

    So the question is (I have tried researching this over a thousand times) "Why is Windows XP stack sending out IGMP v3 membership reports to join the multicast address 239.255.255.250 ?" Is this a valid behaviour based on any RFC or is it simply a bug ?

    It would be great if someone could help me resolve this issue.

    Thanks Guys,

    Legolas >---->>

    Tuesday, June 22, 2010 5:57 PM

Answers