windows 2000 w/novell client ip only

I am in a 2000 user environment that is soon going to windows 2000 pro. We are primarily a Novell shop and we have the novel 4.8 client ready for win2k pro. installing novell client ip only is causing a problem with some users who are losing network connectivity when they dial up an outside resource that is needed for there job function. I would like to know if anyone knows of a way to keep network connectivity on the Lan while also being able to use a modem to connect to another companies resource.