Proxy Server Basics Details _ Proxy Server

The internet has not been unfamiliar to everyone, and now has moved into the vast number of working-class families. More and more companies are also connecting their internal networks to the Internet. Of course there are many ways to access the Internet, for ordinary people, is to buy a modem use PSTN (Public service telephone network) to connect to the Internet. And some companies are generally using DDN or ISDN access, using the way of renting a month. Of course, the individual can not afford the cost of the month, then how to use a telephone line to enable more people to surf the internet? This involves the proxy server (proxy) and how to use the proxy server.

What is a proxy, an agent? Ordinary Internet access is a typical client and server structure: Users use the client program on the computer to make requests to the browser, and the remote WWW Server program responds to the request and provides the appropriate data. And the proxy is between the client and the server, for the server, proxy is the client, proxy requests, server response; For the client, the proxy is the server that accepts the client's request and transfers the data from the server to the client. Its role is very much like the real life of proxy service providers. So the Chinese name of Proxy server is the proxy.

Proxy server works by: When a client sets up proxy server in a browser, your request to access all WWW sites using a browser will not be sent directly to the destination host, but to the proxy server, after the proxy server accepts the client's request, The proxy server makes a request to the destination host and accepts data from the destination host, which is stored on the hard disk of the proxy server, and then the proxy server sends the customer the data requested by the client.
The proxy server has four functions:

First, improve the speed of access. Because the data requested by the customer is stored on the proxy server's hard disk, so the next time this customer or other customers request the same destination site data, will be directly from the proxy server to read the hard disk, the proxy server played a role in caching, the popular site has a lot of customer access, Proxy server advantage is more obvious.

Second, proxy can play a role in the firewall. Because all users using a proxy server must access the remote site through a proxy server, the appropriate restrictions can be set on the proxy server to filter or block out certain information. This is the local Area network network management to the LAN user access limits most commonly used method, is also the local area network user why cannot browse some websites the reason. If a dial-up user uses a proxy server, it must also obey the access restrictions of the proxy server, unless you do not use this proxy server.

Third, through the proxy server to access some of the Web site can not be directly. There are many open proxy servers on the Internet, when the client is restricted to access rights, and the access rights of these proxies are unrestricted, just the proxy server is within the client's access range, then the client can access the target website through the proxy server. Domestic colleges and universities more use of education network, can not go abroad, but through proxy server, can achieve access to the Internet, which is the reason for the hot proxy server in the university.

Iv. security is improved. Whether on the chat room or browsing the site, the purpose of the site can only know that you are from the proxy server, and your real IP can not be detected, which allows users to improve the security.
Proxy server settings:

To set up a proxy server, you must first know the proxy server address and port number, and then fill in the appropriate address and port number on IE or NC's proxy server settings bar. Suppose we have a proxy server with the address Proxy.net.net, the port number is 3000, the configuration method in IE is to use the Internet option/connection/proxy Server to view the menu, and then to the check box in front of the Internet option through the proxy server. In the Address box to fill in the proxy server address, as in this case, assume that the proxy server address is proxy.net.net, and then fill in the Port box with the slogan 3000, click the bottom of the application button, and then click OK, set up. The next time you use IE, users will find that no matter what Web site you browse, ie always first connect with the proxy server. With the NC, set a little more complicated. Using the Preferences menu item under the Edit menu, and then selecting the proxies under Advanced, select the second manral Proxy configuration in the right proxies option, and then point to the view on the right ... button, you will be the Proxy server configuration interface, in the proxy server address and Port number column fill in the corresponding content, click OK, back to the Parameter Settings window, and then click OK, Proxy Server setup work completed. When the customer browses the webpage again, will automatically send the request to the proxy server which you set up, and obtains the data, when browsing the website, either the IE or the NC can clearly see in the browser status bar the first to connect the proxy server, then even the target website process.

However, do not confuse proxy server and router, proxy server is built on the application layer of the service software, and router is a network device or a computer, it is working at the IP layer, the data to the IP layer after the forwarding. Typically, a Proxy server works on a computer that has both a modem and a network card. Different proxy server software provides different services, generally provide www,ftp and other commonly used services. Each passenger plane in the intranet must have a separate IP address configured to use proxy server and point to the proxy server IP address and service port number in connection in the aircraft's control panel-Internet entry. When proxy server starts, it will use Winsock.dll to open up a specified service port, waiting for the passenger plane's request. Your proxy server can work when the modem in Proxy server is dial-up. When you send a connection request to your IE, your passenger plane sends the packet to the proxy server directly, when the server captures the IP packet, it first analyzes what it requests, and if it is an HTTP request, the Proxy Server sends an HTTP request to your ISP, when the proxy When the server receives a response, the IP packet is forwarded to the internal network, and your passenger plane gets the IP packet. In addition, your proxy server can also be a good firewall. Please refer to your proxy server's Readme file for specific actions.

When you visit a Web server on the Internet, do you know how much personal information will be leaked to others? In the process of accessing the Internet, the Web browser will at least more than 20 items about your personal information to the Web server silently without your awareness. This personal information is not a big problem if it is delivered to a reputable web site or a Web server for a large enterprise. It would be deeply disturbing to be sent to a Web server whose Web site is not known to all. The information that a Web browser sends to a Web server is, in the jargon, "environment variables." The main contents are: (1) The IP address (remote_a DDR) and host name (Remote_host) assigned to the computer, (2) the port serial number (Remote_port) used by the Web browser (3) The product name (http_user_agent) of the Web browser and (4) The latest page address (http_referer) of the Web site visited.

Although the above items do not contain personal information such as e-mail addresses and names, the IP address and hostname in (1) are really difficult to be assured in terms of security, but what methods can you use to obscure your IP address?

To solve this problem is very simple indeed. Simply access the Web server through a proxy server. The role of a proxy server is that it can withstand access requests from various terminals for the Web server. In the enterprise network, the proxy server is set on the part of the company's intranet that is linked to the Internet. When dialing on the Internet, you can use the proxy server provided by the Internet connection provider.