Is it a pure DOS shell or is it a command.com/command.exe through Windows 98/XP/2000 etc.?

If it's the latter then you should be able to run ipconfig /all. (this is to only show IP. AFAIK, it's not something you'd find in 6.x). This link might help.

In linux you can do this with ifconfig (this is to show and change the IP)