COMPUTING FOR THE BEWILDERED By Bill Hayles Hello, again. SIMPLE LOCAL AREA NETWORKING Part 2 =================================== Last time, we looked at what you need in the way of hardware and software to set up a simple two computer local area network, and started to configure our two computers. We have called our two computers "machine1" and "machine2" on the workgroup "FREEBIE", and have given them the IP addresses 192.168.0.1 and 192.168.0.2 Today, we're going to complete the process, and introduce a new piece of software, a proxy server. Sharing a Printer ----------------- Probably the commonest use of simple LAN is to share a printer between two computers. We will assume the printer is physically connected to machine1 and we want to use it from machine2. In machine1, select "Control panel" - "Printers". There should be an icon for your particular printer. Right click on the icon and select "sharing" from the menu. All you need to do, under the "sharing" tab is to select "shared as", and give the printer a name. being boring, we'll simply call it "PRINTER". There's no need to add a comment, and no point in adding a password. In machine2, select "Control Panel" - "Printers", then "Add printer". Now select "Network Printer", and allow the system to browse the network. It should find PRINTER on MACHINE1. Select it. We may be required to install some drivers, just as if it were a new printer on our own machine, or Windows may use the drivers on the host machine. But it pays to have the drivers ready in any case. After a reboot, we can now print to the printer on machine1 from machine2 - provided, of course, that machine1 is turned on!. Sharing files ------------- If you wish to share a directory on your hard disk with the other machine, open "My Computer" then navigate to the directory you wish to share. Right click on it and select "sharing". As with a printer, you will be invited to give it a share name, but additionally you can determine what sort of access - read only, full, or password protected, it will have. Once the share is set up, then the share name will show in the network neighborhood of other machines on the LAN. It is perfectly possible to share an entire disk rather than just a folder, but this can have security implications outside the most trusting of LANs. Permanent shares and mapping ---------------------------- Finally, if you have a folder or folders on one computer that you always wish to be available to another, you can map them. Navigate to the share name in Network Neighborhood on the client (recipient) computer and right click on the share. One of the options will be to map it to a (spare) drive letter and to reconnect every time the computer starts. That folder will then appear to be part of the disk structure of the client machine, with its won drive letter, just as long as the host machine is turned on. At boot up time, the host machine MUST be booted first! Sharing an Internet Connection ------------------------------ This is slightly more involved, and will involve the use of a proxy. The proxy I use and recommend, and which is freeware (i.e. you don't have to pay for it) is AnalogX Proxy, which you can download from http://www.analogx.com/contents/download/network/proxy.htm (as will all web addresses printed in the columns of a newspaper, this may not wrap correctly. They should always be input into your browser's address book as a single continuous line without spaces or line breaks). Before we can use our proxy, we need to have a short introduction to ports. A port is a sort of doorway through which specific type of information are exchanged. The TCP/IP protocol allows for 65535 ports, of which the first 1024 are called the "Well known ports". Of those 1024, you're only likely to come across a few, such as Port 25 for SMTP, Port 119 for NNTP, Port 80 for HTTP and 110 for POP3. AnalogX uses "not well known" ports so as not to interfere with other traffic. What you will do is to install your proxy (and I'm going to assume the use of AnalogX) on the host machine - i.e. the one that has the modem or other Internet connection device. The machine which will connect using your LAN and proxy is called the client. We're going to assume that the host is 192.168.0.1 and the client 192.168.0.2 You will to start AnalogX on the host machine and configure it using the configure menu. This will essentially ask you which services you wish to be available to other machines, and which machines can make use of them. Unless you have special needs (in which case you probably already know what you're doing) you will activate HTTP (for web browsing), POP and SMTP (for sending and receiving e-mail) and, possibly FTP for file downloads and NNTP for accessing Usenet (newsgroups). The ports AnalogX proxy uses are HTTP (web browsers) (port 6588) NNTP (usenet newsgroups) (port 119) POP3 (receiving email) (port 110) SMTP (sending email) (port 25) FTP (file transfers) (port 21) Configuring the client machine In essence this merely consists of telling it to use AnalogX instead of attempting to contact the Internet directly or through a dial-up connection. Configuring your browser If you use Internet Explorer, on your client machine just go into the Control Panel->Internet Options, and select the tab 'Connections'. You'll see a button called 'LAN Settings', just click on it, and you'll see the proxy settings. For most systems, all you will need to do is check the 'Use a proxy server' box, enter the IP address of the machine the proxy server is running on (in our example this would be '192.168.0.1', and set the port number# to 6588. Select 'Ok', launch your browser, and away you should be go, provided of course, that the host's dial-up connection or whatever is connected! If you use Netscape, go to the Edit->Preferences->Category->Advanced->Proxies-> Manual->View. Wow! That's a long path! Hope it comes out OK. Here you'll be able to input the IP and port address mentioned in the IE config process. Configuring Email Configuring Email is a little trickier, so make sure you have the web browser proxy working properly before doing this. On the host machine, in AnalogX. open up the 'Configure' menu, and select 'Configure Email Alias's'; you'll be presented with the email account configuration area. Select 'Add' from the menu; this is where you will enter in the servers you check your email from. First, you need to enter the email address that people send messages to, like 'billnot@billnot.com'. Next, you need to set the POP3 server, which is where your email program goes when it receives email; normally this will be something along the lines of 'pop3.domain.com' or 'mail.domain.com'. Finally, you need to set the SMTP server, which is what your emails are sent through, which in the above example could be something like 'smtp.domain.com'. Now, it's important to note that not every service uses two different names for the server, you might check both POP3 and SMTP from the same server; in this case you can just leave the SMTP field blank. That's it for the proxy! Now you have added email support for this particular user. Now you need to set up the configuration of the email program you use; this varies from program to program, but you need to go to wherever you enter both the servers that the program checks. Now, instead of entering 'mail.domain.com' or whatever your mailserver is, you'll enter the IP address of our proxy server, 192.168.0.1'. It's important to note that you won't need to change the port settings in the email program, since the proxy uses the same ports a normal server would. Also, you will set both the SMTP, as well as the POP3 servers to the same IP address; the proxy will make sure they get to the correct place. Now, check out your configuration; try sending an email to yourself (or to me - I don't mind getting test e-mails if it helps). If everything is configured properly, you should be up and running. One more thing to note about email; it will only support using a certain username once; for example, you can't have billnot@billnot.com and billnot@cftb.net; but you can have billnot@billnot.com and bobby@cftb.net. Good luck. That's all for today. Next time, I'll be starting my in-depth look at The Internet for complete newcomers. If you wish to contact me, you can do so by e-mail to questions@billnot.com. Although I can't promise to give everybody an individual reply, I do read everything. My main computer related website is http://cftb.net. If you wish to join our computer chat discussion group (mailing list) you can do so by sending an e-mail to computerchat@billnot.com with the single word SUBSCRIBE as the subject. If you have been, thanks for reading this.