RobertMarkBram - 2004-05-15

Hi All!

I am a tutor in a Masters class at Monash. We are experimenting with UPnP, trying to create a network of services in Java that can co-exist with equal services made available through Jini.

We have had some conflicting test results with the use of UPnP on disconnected Windows systems (standalone).

I am testing with the Ticker/Computer Clocks example. I found on my Windows XP machine that when I disconnected it from the network (Ethernet LAN) no discovery takes place. I installed Microsoft's Loopback device and discovery works ok and the clocks sync.

But some students also running Windows XP have found that even after installing the Loopback device discovery doesn't occur (and the clocks don't sync of course).

Is it possible that there is some other level of configuration we are missing out on?

Is it important to be able to ping 224.0.0.1 for example? I noticed that when I was connected to the LAN (and had no Loopback device) I could ping 224.0.0.1 and get responses - but not from my own IP. When I was disconnected from the LAN (still without a Loopback device) I would get back "Destination host unreachable." messages from pinging 224.0.0.1. After I installed a Loopback device (and was still disconnected from the network) I got "Request timed out." messages.

If you are interested, here are some notes on my testing procedure:
http://phd.netcomp.monash.edu.au/RobertMarkBram/5009/#upnpLoopback

Any advice would be most appreciated!

Rob
:)