Squid introduction and functions

Introduction

The squid service program is the most popular high-performance proxy service software in Unix systems. It is usually used as a front-Cache service for websites, it is used to replace the user's request to the website server for page data and caching. In general, the squid service program will receive the user's request and then automatically download the formulated data (such as the webpage) and stored in the server. When a later user requests the same data, the data stored locally on the server is directly handed over to the user, with less user waiting time.

Function

The squid service program is relatively simple to configure, with high efficiency. It supports data caching for HTTP, FTP, SSL, and other protocols, it also supports content filtering and permission management based on the ACL Access Control List and the ARL access permission list function to prevent users from accessing website resources that are threatened or inappropriate, while ensuring Intranet security, it also improves client access speed and helps reduce network bandwidth. It is especially suitable for installation on servers with large memory and hard disk speed blocks.

The functions are divided into forward proxy and reverse proxy:

Forward proxy allows users to obtain website page data through the squid service program. The specific work forms are divided into standard proxy mode and transparent proxy mode standard forward proxy mode: cache website data locally on the server, improves the efficiency when data resources are accessed again, but the user must

You must specify the IP address and port of the proxy server when accessing the internet. Otherwise, the squid service is not used.

Transparent forward proxy mode: the functional scope Standard forward proxy mode is identical, but you do not need to specify the IP address of the proxy server.

And port number, so this proxy service is completely transparent to users.

The reverse proxy is designed to reduce the load on the website server. The reverse proxy server is responsible for responding to users' static page requests to the original website server, that is

If the reverse proxy server happens to have a user's static state, the cached content is directly sent to the user, reducing some data resource requests to the original server.

 

Squid introduction and functions