If you have a LAN (two or more computers connected in a network, i.e., each has a network card), of which one is connected to the Internet (via a modem, cable, etc.), it may be worthwhile to make the Internet accessible to the other computers on the LAN (the clients) by installing software that will act as a proxy server.
A proxy allows for the sharing of a connection, i.e., it offers access to network computers "by proxy", by redirecting information (generally, the web pages requested by the LAN computers).
However, the larger the number of users, the weaker the bandwidth for each one will be, because the users share the bandwidth of the proxy... Thus, if 8 users are connected on a 56000 baud modem, there will only be 7000 baud per person, which is...not a lot: useless for 8 people surfing the web...
The server will be the LAN computer connected to the Internet. In order to be able to use the Jana server, make sure that the TCP/IP protocol is correctly installed on the computer that will act as the server (Control Panel/Network).
If the server is connected to the Internet via a modem, you should see the two following protocols in the control panel/network window:
Make sure that the IP address (click on the name of your card, then go to the properties tab of the NE2000 compatible card, or 192.168.0.1 (it may be different, but this is the address you conventionally give the proxy). The properties of the TCP/IP protocol of the remote access card are provided by your Internet service provider; they cannot be modified!
If the computer is connected to the Internet via a network card (cable, DSL, or other), there are two possibilities:
Finally, configure the subnet mask to 255.255.255.0
Each of the LAN machines is connected via a network card (via a BNC or RJ45 cable). As in the case of the server, you must set up the TCP/IP protocol on each of the machines connected to the server (clients), and assign them a unique IP address.
The next step is to recover the proxy server (software). We will use Jana Server, a free and effective proxy server, which you can download on CCM:
Download here! (size: 300KB)
After installation and start-up, a red "J" should appear on your toolbar. Just double-click on it, then select "configuration" (you will be asked for a password. Chose a password, but take care to remember it :).
By default, Jana is only configured to manage connections from the web (HTTP protocol).
The number of threads represents the maximum number of simultaneous users who can connect via the proxy, while the maximum number of connections represents the total of sessions that the users can open (a user can open several sessions at a time)
Finally, the page Proxy, Socks defines the ports assigned to each of the services. By default, the HTTP port will be 8080, the SOCKS port will be 1080 (SOCKS4 and 5), and the port assigned to RealAudio will be 1090/554.
To allow clients to access the Internet, it is necessary to configure each application to specify that the connection will be made via the proxy.
Thus, all recent applications related to the Internet (navigators, FTP clients, ICQ, etc.) have a "proxy server" option, sometimes called firewall, an abuse of the term; this option may be like this:
To configure your web browser, just go to preferneces (options, configuration, etc.) and find the option "connect via proxy server".
Then, enter the proxy address into the first field (192.168.0.1) and the port into the second (8080). Certain browsers will ask you for the proxy addresses for each ofthe sevices, the two essential services being http and ftp, for which you will fill in the field as follows.
To configure IE4
To configure IE5
To configure Netscape
Programs such as CuteFTP, WS_FTP, ... generally have an option under preferences that allows you to specify the address of a proxy server, then, enter the address of the computer running Jana Server (192.168.0.1) then enter port 21.
Optionally, a password may be entered if you restricted access on Jana server by assigning passwords to the LAN users.
By means of this process, the LAN computers will have access to FTP sites on port 21. In order to be able to access FTP sites on other ports, you will have to use FTP clients that accept the SOCKS service. SOCKS is a service that allows you to dynamically open ports on the proxy, the only way to use applications having variable ports (FTP on ports other than 21, IRC, etc.).
Messaging or e-mail is the most commonly used service on the Internet; thus, it is essential to be able to use it when sharing a connection on a LAN. E-mail service includes two principal functions:
The configuration of e-mail consists of
The first operation, therefore, is to configure each user in the tab email users of Jana Server, then to add as many users as there are machines connected to the LAN.
|The local settings
area will contain a name, an e-mail address, a login, and a virtual password for the user (parameters that will be those entered by the user in his/her messaging client)
The name of the SMTP sever will be that of the machine connected to the Internet,and the e-mail will be that of the user.
Finally, the parameters of the POP3 account will be those of the user, as if it were his/her machine.
|Each user must configure his/her messaging client with the elements included in the Local Settings area of Jana Server.|
Jana Server and similar free software are available in the download area of this section. The network computers are configured in the same way with the other programs. For details, see the help files of those programs.
If you have questions, feel free to post them in the forum!