2 NIC's, 2 Networks, One Problem

We have a set of computers all connected to the LAN with their internal NIC. We have added a streaming video network, self contained, that has three sources (VBrick encoders multicasting). Eventually we will implement IGMP but until that happens we thought we'd pop a USB to Ethernet adaptor on the computers that need to receive the multicast stream. Both NIC's have static IP's. The internal NIC has "Client for Microsoft Networks", "File and Printer Sharing for Microsoft Networks", and "QoS Packet Scheduler" encabled. They both have TCP/IP enabled. The involved computers are running XP Pro, no SP2.

The internal NIC is connected to the normal LAN and the USB NIC is connected to the streaming network. With both NIC's enabled we can receive the video stream (using the VBrick StreamPlayer Plus application) but cannot surf the internet. With the USB NIC dissabled we can surf but not access the stream (as expected).

Finally the question. How can I tell the computer to only do the multicast on the USB NIC and everything else on the internal NIC?

Thanks,
Doug

Doug,
Are the IPs on the same subnet? If they are that can cause routing issues. It may be that when the video LAN is connected that all traffic gets routed to it, so since it is self contained you lose internet access.

For your final question, of the top of my head I can't think of any way, though playing with the route table might accomplish this. Can I ask why you want to do this?

The internal NIC has an IP of 172.16.x.x with a subnet mask of 255.255.0.0 and the USB NIC has an IP of 192.168.10.39 with a subnet of 255.255.255.0.

Why I want to do this is because we need to receive the video multicast on that computer but can't send the multicast stream over the campus wide LAN because IGMP has not been implimented.

I'm totally open to other suggestions.

Thanks,
Doug