一、什么是hosts文件?

　　hosts是一個沒有擴展名的系統(tǒng)文件，其基本作用就是將一些常用的網(wǎng)址域名與其對應的IP地址建立一個關(guān)聯(lián)“數(shù)據(jù)庫”，

　　當用戶在瀏覽器中輸入一個需要登錄的網(wǎng)址時，系統(tǒng)會首先自動從Hosts文件中尋找對應的IP地址，一旦找到，系統(tǒng)會立即打開對應網(wǎng)頁，如果沒有找到，則系統(tǒng)再會將網(wǎng)址提交DNS域名解析服務器進行IP地址的解析，如果發(fā)現(xiàn)是被屏蔽的IP或域名，就會禁止打開此網(wǎng)頁!

　　二、Win7的hosts 默認文件

　　文件地址：C：WINDOWSsystem32driversetchosts

　　默認里面的內(nèi)容如下：

　　-------------------------------------------------------

　　# Copyright (c) 1993-2009 Microsoft Corp.

　　#

　　# This is a sample HOSTS file used by Microsoft TCP/IP for Windows.

　　#

　　# This file contains the mappings of IP addresses to host names. Each

　　# entry should be kept on an individual line. The IP address should

　　# be placed in the first column followed by the corresponding host name.

　　# The IP address and the host name should be separated by at least one

　　# space.

　　#

　　# Additionally， comments (such as these) may be inserted on individual

　　# lines or following the machine name denoted by a ‘#’ symbol.

　　#

　　# For example：

　　#

　　# 102.54.94.97 rhino.acme.com # source server

　　# 38.25.63.10 x.acme.com # x client host

　　# localhost name resolution is handled within DNS itself.

　　# 127.0.0.1 localhost

　　# ：：1 localhost