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Youll also want to keep current on service packs for your operating system. For example, as of this writing, NT Server 4.0 should have Service Pack 3 installed, and Service Pack 4 is just around the corner.
In a nutshell, you can overcome Web server reliability problems by exercising the divide-and-conquer practices from Hour 4, The Napoleon Method: Divide and Conquer, and look up specific error messages by using the techniques from Hour 7, The Simple Simon Approach: The Benefits of Being Too Stupid to Quit, But Too Smart to Keep Tackling a Complex Problem Head On.
Third-Server Problems
Even though your Web server is running smoothly and dishing out HTML to beat the band, you still might experience problems with your intranet applications. Intranet applications tend to rely on more than one server, so its a good idea to have a diagram of how these applications interact with each other. For an example, see Figure 19.7, a diagram of an intranet application called Knowledgenet. See how the Web server itself is just one piece. For the application to work, the remote control thin client server must be functioning, and the CD-ROM server must also be functioning. Notice how the CD-ROM server only speaks IPX/SPX and is a Novell serverits not a TCP/IP server.
Figure 19.7 A sample thin client multiprotocol, multiserver intranet.
The bottom line is this: Even though your Web server is functioning, any one of the other two components malfunctioning makes the entire intranet application stop working. Again, documentation is key here; if someone tells you that the Knowledgenet application is not working and you pull up this diagram, you naturally know which servers to check.
Proprietary email is basically a client/server application or, in some cases, a specialized file-sharing application. When trouble arises with your proprietary email system (such as GroupWise, Lotus Notes, or Exchange), youre best off checking your product documentation and using the file-and-print or client/server troubleshooting techniques we discussed in Hour 18.
However, each one of these proprietary email systems also supports Internet/intranet standards and provides gateways to hook up to the Internet at large. Internet (and therefore intranet) email has three components:
You can telnet to socket 25 to check whether SMTP gateways are up and accepting connections. Heres an example:
$ telnet wpo 25 Trying 167.195.160.7 Connected to wpo.co.chatham.ga.us. Escape character is ^]. 220 wpo.co.chatham.ga.us GroupWise SMTP/MIME Daemon 4.11 Ready 1993, 1996 Novell, Inc.
You can also telnet to the POP socket (socket 109 and socket 110, depending on the version of POP that youre using) and the IMAP socket (socket 143) to make sure that the servers that are supposed to be accepting these types of connections are up. Heres an example:
$ telnet moria 143 Trying 167.195.160.6 Connected to moria.co.chatham.ga.us. Escape character is ^]. * OK moria.co.chatham.ga.us IMAP4rev1 v10.170 server ready
If youre having trouble getting outside mail from the Internet to your intranet, youll want to use nslookup to check your MX record for your zone. An MX record is a special record denoting the mail exchanger for your zone. Heres an example:
$ nslookup > set type=mx > co.chatham.ga.us co.chatham.ga.us preference = 10, mail exchanger = moria.co.chatham.ga.us moria.co.chatham.ga.us internet address = 167.195.160.
If its not the right server or if you dont even have one, youll need to change this on your DNS server or ask your ISP to do it for you.
Do you run into problems with the following types of dialing?
Huh? Dialing out of your intranet and into the Internet? Even when you have an Internet connection? Dont laughit happens more often than youd think. Either theres a Neanderthal policy handed down from above that the Internet will not be used for personal use or folks just dont feel comfortable using the Internet for nonwork-related business.
Dialing out of your IP network and into someone elses intranet is also reasonably common. Therefore, lets take a look at the technical implications of dialing out of your IP network and into another IP network (whether the Internet or another intranet), along
Youll want to let users know that they might not be able to get to local TCP/IP applications while theyre dialed in to another network.
Microsoft dialup networking will offer to clear the existing DNS servers. Let your users know that they should not do this; otherwise, theyll be unable to access your local area network services.
with some common problems that folks encounter.
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