Linux下规则文件.htaccess(手工创建.htaccess文件到站点根目录)

<IfModule mod_rewrite.c>
RewriteEngine On
#Block spider
RewriteCond %{HTTP_USER_AGENT} "SemrushBot|Webdup|AcoonBot|AhrefsBot|Ezooms|EdisterBot|EC2LinkFinder|jikespider|Purebot|MJ12bot|WangIDSpider|WBSearchBot|Wotbox|xbfMozilla|Yottaa|YandexBot|Jorgee|SWEBot|spbot|TurnitinBot-Agent|mail.RU|curl|perl|Python|Wget|Xenu|ZmEu" [NC]
RewriteRule !(^robots\.txt$) - [F]
</IfModule>

Windows2008、2012或更高系统下规则文件web.config (手工创建web.config文件到站点根目录)

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
   <rewrite>
    <rules>
     <rule name="Block spider">
      <match url="(^robots.txt$)" ignoreCase="false" negate="true" />
      <conditions>
      <add input="{HTTP_USER_AGENT}" pattern="SemrushBot|Webdup|AcoonBot|AhrefsBot|Ezooms|EdisterBot|EC2LinkFinder|jikespider|Purebot|MJ12bot|WangIDSpider|WBSearchBot|Wotbox|xbfMozilla|Yottaa|YandexBot|Jorgee|SWEBot|spbot|TurnitinBot-Agent|mail.RU|curl|perl|Python|Wget|Xenu|ZmEu" ignoreCase="true" />
      </conditions>
       <action type="AbortRequest"/>
     </rule>
    </rules>
   </rewrite>
  </system.webServer>
</configuration>

注：“{HTTP_USER_AGENT}”所在行中是不明蜘蛛名称，根据需要添加以"|"为分割。
  规则中默认屏蔽部分不明蜘蛛，要屏蔽其他蜘蛛按规则添加即可,附各大蜘蛛名字：
  google蜘蛛：googlebot
  百度蜘蛛：baiduspider
  百度手机蜘蛛：baiduboxapp
  yahoo蜘蛛：slurp
  alexa蜘蛛：ia_archiver
  msn蜘蛛：msnbot
  bing蜘蛛：bingbot
  altavista蜘蛛：scooter
  lycos蜘蛛：lycos_spider_(t-rex)
  alltheweb蜘蛛：fast-webcrawler
  inktomi蜘蛛：slurp
  有道蜘蛛：YodaoBot和OutfoxBot
  热土蜘蛛：Adminrtspider
  搜狗蜘蛛：sogou spider
  SOSO蜘蛛：sosospider
  360搜蜘蛛：360spider  

apache、iis屏蔽限制ip访问(适用虚拟主机)