Unable to see lookout processes across network

[Zadnik]

We've had a problem recently with a computer being unable to see the processes running on another lookout computer. The 2 machines can see one another and access one another just fine across the LAN.  One of the 2 computers can see the processes running on the other, if you go to connection browser and click on network and then click on the other computers name, you will see the processes that are open and active.
However the other computer cannot see the processes that are running on the first computer. The name appears in the list and is registered, but if you click the computer name it will tell you that it has no processes open or it is disconnected from the network. Which it is not disconnected from the network.
PC 1 is Windows 2000 Pro
PC 2 is Windows XP Pro
Anybody have ideas?
Thanks ahead

[DimensionFinder]

Hi Zadnik:

Hmm this seems like an issue with the Windows XP firewall. Do you have SP 2?

This knowledgebase might help:
http://digital.ni.com/public.nsf/websearch/1708e8a3106c1c3886256e5b005072fe

Best Regards,
Jaideep

[Zadnik]

Unfortunately it is not the microsoft firewall problem  (tear). The Windows XP Pro machine is running service pack 1. We are still pressing forward checking all network settings and such but as of now we are coming up empty handed.
If ya'll have any other ideas, we appreciate your replies.

[Doug M]

Zadnik,
Have you restarted your computers since experiencing this?  Is lkads.exe running on both machines? Was this ever working?

To browse remote processes, Lookout uses the National Instruments Logos protocol, which is built on top of UDP, so if one computer cannot browse to another, it is very likely the UDP ports are somehow getting blocked, either by software, or hardware.  Try putting both computers on the same physical network hub.  If this solves the issue then there is some sort of hardware firewall or port blocking going on.  Please see this KB for more details on exact ports.