For Windows boxes, no domain name is needed, because NetBIOS names are used instead. But Linux or any other Unix-like OS will ask you for the domain name during install. If you own a domain name, you can use it, provided that you avoid server names of www, ftp or anything that is publicly reachable from the internet. And if your web hosting provider resolves [anything}.domain.com to your website, you CANNOT use the name internally. You need to set the machines up with an obviously fake domain name, like machine1.penguin.fake or mybox.localdomain. Just make sure that the names are unique for each machine.

Unix machines connect by a whole host of methods not available to Windows machines until recently. You can telnet into another Unix box. Windows computers can use Telnet AS A CLIENT FUNCTION, but not as a server function unless the Telnet Server is installed (it's available for Windows-2000). And of course you can always connect (if a web server is installed) to the default directory for web pages via a web browser. There are other services such as NFS (Network File Services) as well. But the one that has gained a lot of popularity in Samba, for it allows connection to Windows networks.

The server part of Samba is easiest to set up. You just have to make sure that Samba is installed (it is by default) and automatically started at boot-up, the right entries are in the /etc/smb.conf file, set up your accounts, and by default, each user's files are shared off the /home/[username] directory. Client functions are handled in two ways -- smbclient and smbmount. Smbclient just establishes a connection and allows the transfer of files one at a time. Smbmount, on the other hand, requires root [or superuser] access and can permit the access of whole network shares not only from a Windows computer but also from another Unix box that happens to be running Samba. Incidentally, I've noticed that a popular Linux -- Mandrake 7 -- should be installed as an Expert installation to make sure you can (manually) select all possible packages, taking up about 1.4 G if done this way. Otherwise it installs with the server and not the client functions for SMB.

If you want to connect FROM or TO Unix machines outside the SMB protocol (for example through a web browser), you'll either have to type in the IP address or have a method of resolving host names. In a large network, this task falls to a DNS server. But with NT4, Windows 2000, or Linux on a small network, all you need is a hosts file (its name is 'hosts' without any extension), which should on a line by line basis state the IP address followed by the name of the machine. For linux, the hosts file is in the /etc directory, and for Windows-NT or 2000, it's in the \WINNT\system32\drivers\etc folder. For Windows-9X, the file should be placed in the C:\WINDOWS directory. If you open Notepad, and tell it to search for All Files, you will see a file called Hosts.sam. It is a sample file. Open it, take out the explanatory information, and make sure the first line reads
127.0.0.1 localhost.
Add the appropriate lines (e.g. 192.168.0.35 penguin.localdomain). Save it under the name of 'hosts' without any extension. Now here's where the problem occurs with Windows. Notepad, in its infinite wisdom, automatically appends a .txt extension. You'll have to exit Notepad, go into Windows Explorer, and rename the file to take off the extension. (Ignore the warning that the file may become unusable if you change the extension). Once that is done, you may immediately make use of the file without restarting your computer.

Windows 3.1 if you recall does not ship with TCPIP. Even if you install TCPIP-B from Microsoft, you need to distribute a physical list of IP addresses to 3.1 users or set up a DNS server. It is not designed to resolve host names via a hosts file. In fact this was one of the reasons why 95 was invented.