Linux-to-Linux

UNIX (and therefore Linux) was designed for file sharing from the beginning, and so the setup is very straightforward, as shown below.

Windows File Sharing

• Windows and IBM established the NetBIOS protocol (API) for computer-to-computer networking, with an underlying NetBEUI transport layer. NetBIOS also was implemented for Novell and more importantly, TCP/IP.
• NBT (NetBIOS over TCP/IP) was implemented on all Windows since Win95 as well as on OS/2.
• Windows called this SMB (Server Message Block) service, although they now seem to prefer the term CIFS (Common Internet File System) instead. Same thing.

Samba

Samba is an open-source program to implement SMB on a UNIX or Linux system, causing it to masquerade as just another Windows box.

• SMB has two main services:
  1. The obvious File and Printer Sharing, and
  2. Name Resolution completely independent of the Internet's DNS. (A box in a shared network which is also connected to the Internet thus has two names, although if you are smart, you will make both of them the same!)
• Each LAN has at least one WINS (Windows Internet Name Server), which can be either a Linux or Windows system, used to resolve SMB names in the same manner as DNS.
• Samba therefore has two possible daemons running:
  1. smbd, the Samba daemon, which handles both server and client data services.
  2. nmbd, the WINS server, if necessary.

Setting Up the JOHN Local Area Network

At the moment, my household consists of the following:

• gateway, 192.168.1.1, the router to the Internet, running FLOPPYFW.
• athlon, 192.168.1.3, my desktop, running SuSE 8.2.
• dell, 192.168.1.7, my laptop, running SuSE 8.2.
• photo, 192.168.1.8, my photo processor, running Windows 98SE.
• Assorted other machines as necessary — my old laptop, Becky's Win98 machine, the CTPCUG laptop, etc.
• All these are connected to a 10/100 Ethernet switch.

From my point of view, the JOHN LAN (aka Workgroup) will consist of athlon, dell, and photo, all of which have 100mbit full-duplex Ethernet. I wish to share file directories (and eventually printers, CD-ROM burner, scanner, etc.) in both directions between all three machines.

VERY IMPORTANT NOTICE — I am the only user of these three machines, they are under my physical control, and they are isolated from the Internet behind a firewall. As such, there is no real need to have any machine-to-machine security. (The only person who could hack into them (i.e., the only other person with a computer behind the firewall) is Becky, and she would find it much easier to walk down the hall and use the computer in question directly!) The discussion below gets much more complicated if we have to get into security issues. Be aware that what I am about to show leaves all three machines wide open to each other.

Linux-to-Linux

• The NFS protocol provides the Network File Sharing.
• The NFS Server provides files, and the NFS Client uses them.
• Both are easily configured in SuSE via YaST Network Services.
• The NFS Server screen allows the user to (a) show the files/directories to be shared by the current machine, and (b) which systems are permitted to use them.
• The NFS Client screen sets up the /etc/fstab entry — i.e., where the other computer's shared resource will be mounted on the current machine.
• Once this is done on both the athlon and dell Linux machines, the resources appear in the respective Linux directory structures and can be used exactly as if they were local.
• Note that the computers are identified by their IP addresses and/or DNS names, in accordance with UNIX practice.

Setting up Samba on the Linux Side

• Samba is controlled by the file /etc/samba/smb.conf, which can be edited manually or through the supplied Samba Web Administration Tool — SWAT. The entries in smb.conf control, among other things:
  • Global stuff like the name of the LAN, security issues such as whether "guest" machines will be allowed access, passwords for the allowed users, etc. Note: if the Windows side is Win98 or higher, be sure to globally set "Use Encrypted Passwords" or nothing will work right.
  • Shares, including the local path, whether access is to be read-only, etc.
• SWAT provides excellent help documentation for all options.
• When you think you have everything set up, use the testparm program to validate smb.conf.
• Use YaST to configure inetd (the Internet services super-daemon) to run smbd and, if desired nmbd. Since the laptop will not always be present and the Winbox isn't stable, athlon will be the name server. BTW, set up inetd to run SWAT, too.
• Use the program smbstatus to see if everything looks good on the Linux side.

Setting up SMB on the Windows Side

• Go to Control Panel-->Network-->Configuration to be sure TCP/IP is set up.
  • At -->WINS Configuration, enable WINS resolution and provide the IP address of the WINS server. In this case, 192.168.1.3 (athlon).
  • At -->Bindings, double check that "Client for Microsoft Networks" and "File and Printer Sharing" are available.
• At -->Network-->Identification, enter the Windows computer's SMB name (photo) and workgroup (JOHN).
• At this point, (after rebooting once or twice, of course)you should be able to go to "Network Neighborhood" and see the directories being offered by the athlon and dell Linux boxes.
• In Windows, remote directories are identified as a UNC in the form \\hostname\sharename. For instance, if the \usr\images directory on the Linux desktop is shared under the name images, then a file in that directory might be accessed in Windows as \\athlon\images\myfile.jpg.
• To make life easier, execute the command net use <drive> <UNC> for each directory shared from the Linux machines. E.g., net use I: \\athlon\images will allow Windows 98 to see athlon's \usr\images directory as the "I:" drive instead, so one could simply use I:\myfile.jpg.

References

1. Using Samba, 2nd Edition, Eckstein and Collier-Brown, O'Reilly, 2003. Has step-by-step instructions for setting up everything, with examples from Win98, WinME, and WinXP.
2. The Samba documentation installed on Linux with the software. The easiest way to access them is via SWAT. They are quite extensive and amazingly readable.