Basic Connectivity

Now that you understand the differences between the security models of Windows 2000 and UNIX, let's look at how they are compatible. For one thing, with no additional add-ons, Windows 2000 coexists reasonably well with UNIX servers. The default networking protocol for both operating systems is now the same—TCP/IP. They can easily share DNS, DHCP, and other services. Simple connectivity between Windows 2000 and UNIX can be handled by FTP and Telnet.

File Transfer Protocol

All versions of Windows 2000 include a simple FTP command-line client and can handle FTP from within Microsoft Windows Explorer to a limited extent. The character-mode client provides no frills but should feel quite comfortable to the UNIX user—and it works without quirks. Those who want a more graphical, friendly FTP client have a variety to choose from, including shareware, and some that are pure freeware. A personal favorite is WS_FTP Pro from Ipswitch (http://www.ipswitch.com). Windows 2000 also includes a full-featured FTP server as part of the Internet Information Services (IIS) suite. With both an FTP server and a client natively available, you can easily copy files between the UNIX and Windows 2000 machines on your network.

Telnet

All versions of Windows 2000 come with the new character-mode Telnet client that debuted in Services for UNIX. The semigraphical Telnet client that had been around since Microsoft Windows 3 is finally gone. The new client is faster, has better terminal emulations, and is actually quite decent for most uses. It supports American National Standards Institute (ANSI)—including color, VT52, VT100, and VTNT, a special emulation that can be useful when running character-mode Windows 2000 applications such as Edit. If your need for terminal emulation isn't met by one of these modes, there are excellent third-party commercial Telnet clients available.

Real World

Secure Shell (SSH)

Telnet and FTP, although great and useful protocols, have an inherent security risk, as they transmit information, including passwords, across the network in plain text without encryption. This can be acceptable in many situations where the internal network is thoroughly protected from outside intrusion, and internal users are all trusted, but it poses unacceptable risks in other situations. One solution to this, and the de facto standard in the UNIX world, is the SSH protocol, a secure, encrypted protocol that supports a Telnet-like character mode logon, an FTP-like file transfer protocol, and additional features.

There are both commercial and open source versions of SSH available. Of the commercial versions, F-Secure SSH is the only one that is certified, and it supports virtually all UNIX operating systems, as well as Windows 2000. It even has a version for Services for UNIX version 3, with Interix. OpenSSH is widely available in both compiled forms and as source code.

Windows 2000 Server even has a built-in Telnet daemon, or server. This server is similar to the excellent one shipped as part of SFU, but it's limited to two simultaneous connections.