The application of Squid in enterprise network

One: Squid introduction:

Squid is a kind of excellent proxy server software used in Linux system. Squid is a software that caches Internet data, receives a user's download request, and processes the downloaded data automatically. That is, when a user wants to download a home page, it sends a request to squid to download it for it, then squid connects to the requested Web site and requests the home page, and then passes the home page to the user while retaining a backup, when other users apply for the same page, Squid passes the saved backup to the user immediately, making the user feel very fast.

Second: CDN Introduction:

The full name of CDN is content Delivery network, that is, contents distribution network. The goal is to add a new layer of network architecture to the existing Internet, publish the content of the Web site to the nearest user's network "edge", so that users can get the required content nearby, improve the user's response speed to visit the site. From the technical comprehensive solution because of the network bandwidth is small, the user accesses the quantity to be big, the dot distribution unequal problem, enhances the user to visit the website the response speed. To better understand the CDN, let's look at the workflow of the Cdn. When a user accesses a Web site that has already joined CDN Services, it first determines the best CDN node of the nearest user through DNS redirection technology, and points the user's request to the node. When the user's request arrives at the specified node, the CDN server (the cache on the node) is responsible for providing the user with the content requested by the users.

Four advantages of CDN network accelerator:

High-speed: Improve the Enterprise site (especially contains a large number of pictures and static page site) access speed, and greatly improve the nature of the above site stability

Practical: When the Enterprise site stored in the server short downtime, users can still visit the cache server for a long time, access to the enterprise site information;

Simple: CDN network accelerator is completely transparent to users, purchase, use convenient, do not need to make any changes to its space, does not affect the original space maintenance operation and operation content;

Value: The company to provide a scalable CDN all cache servers as well as dedicated DNS hardware and bandwidth, one purchase, can be in the local telecommunications room automatically for you to "clone" a number of copies of the site, so that the site all over the Internet.

Three: Forward agent and reverse proxy

The forward proxy is a server located between the client and the original server (Origin server), in order to obtain content from the original server, the client sends a request to the agent and specifies the target (the original server), and the agent then forwards the request to the original server and returns the obtained content to the client. The client must make some special settings to use the forward proxy.

Contrary to the reverse proxy, it is like the original server for the client and the client does not need to make any special settings. The client sends a normal request to the contents of the reverse proxy's namespace (name-space), and then the reverse proxy determines where (the original server) forwards the request and returns the obtained content to the client as if it were its own.