Jul 01 2008
Using TPXMDIView on Windows Vista
A change to the Windows TCP/IP stack (actually, a complete rewrite) breaks some IPv4 Multicast application including TPXMDIView on Windows Vista and Windows 2008.
The default address used by Teleplex and TPXMDIView is “225.0.0.1″. Apparently, the system ignores multicast packets where the lowest part of the address is “1″. In fact, you can’t even see the packets with Wireshark (Ethereal).
However, if you change the multicast address to any other valid, non-reserved multicast address, it works.
We have changed the default multicast address in Teleplex and TPXMDIView to “225.0.0.225″. However, if you want to use TPXMDIView in an existing installation on one or more Vista systems, you must change the current settings in Teleplex and all of the client machines that run TPXMDIView so that they match. Also, if you have a router for a multi-subnet LAN and must pass TPXMDIData between subnets, you must enable Multicast pass-through fon the router or the new address.
Why this is so is still under investigation.