The Quote of the Day is a troubleshooting protocol, more or less, specified in RFC 865 back in the day. It's supposed to do nothing more than respond to a connection by returning a string of text (usually a famous quote) and then closing the connection. This protocol was assigned TCP/UDP port 17, but was rarely implemented, as I suppose people had better things to do. In this century, of course, all of these "small servers" as Cisco calls them, or "simple TCP/IP services" as Microsoft calls them, have fallen out of favor with the security community along with the rest of the protocols from that era, like rcp, rsh, etc. Nevertheless, you can still have a bit of fun with this protocol. It might even be useful.
To implement on a Microsoft server, such as Windows 2000 Server, edit the text file %systemroot%/system32/drivers/etc/quotes with Notepad, and save, making sure you do not add an extension, like .txt to the file. Next, open the Services dialog from the Administrative Tools menu or the Control Panel, and start the "Simple TCP/IP Services" service. It will most likely be disabled. Be advised that this also enables the Chargen, Echo and Daytime services, which are notorious security problems.
Now, from another computer, open a command prompt window and telnet to the server on port 17. If your server's IP address is 192.168.1.10, this command would be:
c:\>telnet 192.168.1.10 17
Repeat this several times. It should respond each time with a different quote from your file and close the connection each time, leaving you back at your command prompt.
Well, that's good for a few minutes of entertainment, but what really could you accomplish with it? I'd like to say you could configure the "server-motd command" on Cisco's IOS in conjunction with the login banner and motd commands to create a dynamic login banner that could be controlled from a central server. Sadly, that command doesn't exist. In fact, there are few qotd clients anywhere. Even so, it's easy enough to add the telnet command above to any user login script.
Once you've got it displaying on your clients, you can fill the text file with anything from entertaining quotes, to job-related tips, to computer advice, or even something a little more sophisticated since the quotes are handed out round-robin sequentially. This could even be used as a cheap scheduler.
Tom Lancaster, CCIE# 8829 CNX# 1105, is a consultant with 15 years experience in the networking industry, and co-author of several books on networking, most recently, CCSPTM: Secure PIX and Secure VPN Study Guide published by Sybex.