Oleg Deribas responded to a thread in the FreeDOS mailing list about networking. Here is his note on networking FreeDOS in a Windows networking:
It is 'Microsoft Network Client version 3.0 for MS-DOS' and it can be freely downloaded from ftp site. As I understand, the license allows free using of this software.
Yes, it fits one floppy, and I tried to use it with freedos. It works. I can mount shares from my linux samba server, but it uses so much memory that I can't run any program after that :) With IBM PC-DOS 7.0 the same TSRs use not so much memory. I don't know, why...