Indeed. DOS is not a network operating system. It is a PC operating system. There is no native support for PC to PC communication built into DOS.

That being said, there are a number of network operating systems that could support DOS clients. As Slarty (short for Slartibartfast?) alluded, NetWare was probably the most popular network operating system used to support DOS clients.

You should be able to tell if you are in a NetWare environment based on the login prompt.

Another thing to look for would be to execute the PATH command to show your path. You should see more than just the local drive if you are on a network. Generally speaking in a NetWare environment you'll see the Z:\ drive listed in your search path. This is usually mapped to the \PUBLIC directory on the server you're connecting to.

It has been a long time since I worked on a NetWare 3.1x system with a DOS-based client PC.

You should be able to get some documentation from Novell

Of course this only pertains to NetWare. There were a few other NOSes around that supported DOS clients too...