There is no ping and dns with IPX/SPX. AFAICR, there's not even file sharing (between DOS clients). That's Novell networking for you. (; I used to run Netware at home, and had much "fun" with it.
Anyway, Jappie, there seems to be a misunderstanding here. Vanilla DOSBox does not support "real" IPX. It's using a IPX over TCP (or UDP, i think) implementation. This means you can't connect DOSBox to a "real" IPX network. I don't know about hal's build, though. Setting up IPX in DOS is not an easy thing to do. You need to start a sh*tload of drivers, and they take up much conventional memory.
It'd much easier if the other machine was running DOSBox (and TCP/IP networking), too. But the other machine is probably not the fastest one, i assume - otherwise it wouldn't run Windows 9x. DOSBox should run in Win9x, but it'll be slow.
There's no real solution to your problem, i think. Either hal's build really does support "real" IPX networking (then you're in for a lot of configuring), and you can use that, or you'll have to connect to a faster machine running DOSBox.
EDIT: hal's "Megabuild" indeed does support "real" IPX in DOSBox. See his website for instructions.