如何设置能限制某个ip某一时间段的访问次数是一个让人头疼的问题，特别面对恶意的ddos攻击的时候。其中cc攻击（challenge collapsar）是ddos（分布式拒绝服务）的一种，也是一种常见的网站攻击方法，攻击者通过代理服务器或者肉鸡向向受害主机不停地发大量数据包，造成对方服务器资源耗尽，一直到宕机崩溃。cc攻击一般就是使用有限的ip数对服务器频繁发送数据来达到攻击的目的，nginx可以通过httplimitreqmodul和httplimitzonemodule配置来限制ip在同一时间段的访问次数来防cc攻击。httplimitreqmodul用来限制连单位时间内连接数的模块，使用limit_req_zone和limit_req指令配合使用来达到限制。一旦并发连接超过指定数量，就会返回503错误。httplimitconnmodul用来限制单个ip的并发连接数，使用limit_zone和limit_conn指令这两个模块的区别前一个是对一段时间内的连接数限制，后者是对同一时刻的连接数限制。
HttpLimitReqModul 限制某一段时间内同一ip访问数实例
<span>http<span>{<span> <span>...<span>
<span>#定义一个名为allips的limit_req_zone用来存储session，大小是10M内存，<span> <span>#以$binary_remote_addr 为key,限制平均每秒的请求为20个，<span> <span>#1M能存储16000个状态，rete的值必须为整数，<span> <span>#如果限制两秒钟一个请求，可以设置成30r/m<span>
limit_req_zone $binary_remote_addr zone<span>=<span>allips<span>:<span>10m<span> rate<span>=<span>20r<span>/<span>s<span>;<span> <span>...<span> server<span>{<span> <span>...<span> location <span>{<span> <span>...<span>
<span>#限制每ip每秒不超过20个请求，漏桶数burst为5<span> <span>#brust的意思就是，如果第1秒、2,3,4秒请求为19个，<span> <span>#第5秒的请求为25个是被允许的。<span> <span>#但是如果你第1秒就25个请求，第2秒超过20的请求返回503错误。<span> <span>#nodelay，如果不设置该选项，严格使用平均速率限制请求数，<span> <span>#第1秒25个请求时，5个请求放到第2秒执行，<span> <span>#设置nodelay，25个请求将在第1秒执行。<span>
limit_req zone<span>=<span>allips burst<span>=<span>5<span> nodelay<span>;<span> <span>...<span> <span>}<span> <span>...<span> <span>}<span> <span>...<span><span>}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>HttpLimitZoneModule 限制并发连接数实例
limit_zone只能定义在http作用域，limit_conn可以定义在http server location作用域
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<span>http<span>{<span> <span>...<span>
<span>#定义一个名为one的limit_zone,大小10M内存来存储session，<span> <span>#以$binary_remote_addr 为key<span> <span>#nginx 1.18以后用limit_conn_zone替换了limit_conn<span> <span>#且只能放在http作用域<span> limit_conn_zone one $binary_remote_addr <span>10m<span>;<span>
<span>...<span> server<span>{<span> <span>...<span> location <span>{<span> <span>...<span> limit_conn one <span>20<span>;<span> <span>#连接数限制<span>
<span>#带宽限制,对单个连接限数，如果一个ip两个连接，就是500x2k<span> limit_rate <span>500k<span>;<span>
<span>...<span> <span>}<span> <span>...<span> <span>}<span> <span>...<span><span>}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>nginx白名单设置
以上配置会对所有的ip都进行限制，有些时候我们不希望对搜索引擎的蜘蛛或者自己测试ip进行限制，
对于特定的白名单ip我们可以借助geo指令实现。
1.
<span>http<span>{<span> geo $limited<span>{<span> <span>default<span> <span>1<span>;<span> <span>#google <span> <span>64.233<span>.<span>160.0<span>/<span>19<span> <span>0<span>;<span> <span>65.52<span>.<span>0.0<span>/<span>14<span> <span>0<span>;<span> <span>66.102<span>.<span>0.0<span>/<span>20<span> <span>0<span>;<span> <span>66.249<span>.<span>64.0<span>/<span>19<span> <span>0<span>;<span> <span>72.14<span>.<span>192.0<span>/<span>18<span> <span>0<span>;<span> <span>74.125<span>.<span>0.0<span>/<span>16<span> <span>0<span>;<span> <span>209.85<span>.<span>128.0<span>/<span>17<span> <span>0<span>;<span> <span>216.239<span>.<span>32.0<span>/<span>19<span> <span>0<span>;<span> <span>#M$<span> <span>64.4<span>.<span>0.0<span>/<span>18<span> <span>0<span>;<span> <span>157.60<span>.<span>0.0<span>/<span>16<span> <span>0<span>;<span> <span>157.54<span>.<span>0.0<span>/<span>15<span> <span>0<span>;<span> <span>157.56<span>.<span>0.0<span>/<span>14<span> <span>0<span>;<span> <span>207.46<span>.<span>0.0<span>/<span>16<span> <span>0<span>;<span> <span>207.68<span>.<span>192.0<span>/<span>20<span> <span>0<span>;<span> <span>207.68<span>.<span>128.0<span>/<span>18<span> <span>0<span>;<span> <span>#yahoo<span> <span>8.12<span>.<span>144.0<span>/<span>24<span> <span>0<span>;<span> <span>66.196<span>.<span>64.0<span>/<span>18<span> <span>0<span>;<span> <span>66.228<span>.<span>160.0<span>/<span>19<span> <span>0<span>;<span> <span>67.195<span>.<span>0.0<span>/<span>16<span> <span>0<span>;<span> <span>74.6<span>.<span>0.0<span>/<span>16<span> <span>0<span>;<span> <span>68.142<span>.<span>192.0<span>/<span>18<span> <span>0<span>;<span> <span>72.30<span>.<span>0.0<span>/<span>16<span> <span>0<span>;<span> <span>209.191<span>.<span>64.0<span>/<span>18<span> <span>0<span>;<span> <span>#My IPs<span> <span>127.0<span>.<span>0.1<span>/<span>32<span> <span>0<span>;<span> <span>123.456<span>.<span>0.0<span>/<span>28<span> <span>0<span>;<span> <span>#example for your server CIDR<span> <span>}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>geo指令定义了一个白名单$limited变量，默认值为1，如果客户端ip在上面的范围内，$limited的值为0
2.使用map指令映射搜索引擎客户端的ip为空串，如果不是搜索引擎就显示本身真是的ip，这样搜索引擎ip就不能存到limit_req_zone内存session中，所以不会限制搜索引擎的ip访问
map $limited $limit {
1 $binary_remote_addr;
0 "";
}
3.设置limit_req_zone和limit_req
limit_req_zone $limit z rate=10r/m;
limit_req z burst=5;
最后我们使用ab压php-fpm的方式，对上面的方法效果实际测试下
例1：限制只允许一分钟内只允许一个ip访问60次配置，也就是平均每秒1次
首先我们准备一个php脚本放在根目录下$document_root
test.php
nginx配置增加limit_req_zone 和 limit_req
<span>http<span>{<span> <span>...<span> limit_req_zone $binary_remote_addr zone<span>=<span>allips<span>:<span>10m<span> rate<span>=<span>60r<span>/<span>m<span>;<span> <span>...<span> server<span>{<span> <span>...<span> location <span>{<span> <span>...<span> limit_req zone<span>=<span>allips<span>;<span> <span>...<span> <span>}<span> <span>...<span> <span>}<span> <span>...<span><span>}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>ab -n 5 -c 1 http://www.weizhang.org/test.php
118.144.94.193 - - [22/Dec/2012:06:27:06 +0000] "GET /test.php HTTP/1.0" 200 11000 "-" "ApacheBench/2.3"
118.144.94.193 - - [22/Dec/2012:06:27:06 +0000] "GET /test.php HTTP/1.0" 503 537 "-" "ApacheBench/2.3"
118.144.94.193 - - [22/Dec/2012:06:27:07 +0000] "GET /test.php HTTP/1.0" 503 537 "-" "ApacheBench/2.3"
118.144.94.193 - - [22/Dec/2012:06:27:07 +0000] "GET /test.php HTTP/1.0" 503 537 "-" "ApacheBench/2.3"
118.144.94.193 - - [22/Dec/2012:06:27:07 +0000] "GET /test.php HTTP/1.0" 503 537 "-" "ApacheBench/2.3"
未设置brust和nodelay可以看到该配置只允许每秒访问1次，超出的请求返回503错误
<span>http<span>{<span> <span>...<span> limit_req_zone $binary_remote_addr zone<span>=<span>allips<span>:<span>10m<span> rate<span>=<span>60r<span>/<span>m<span>;<span> <span>...<span> server<span>{<span> <span>...<span> location <span>{<span> <span>...<span> limit_req zone<span>=<span>allips burst<span>=<span>1<span> nodelay<span>;<span> <span>...<span> <span>}<span> <span>...<span> <span>}<span> <span>...<span><span>}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>ab -n 5 -c 1 http://www.weizhang.org/test.php
118.144.94.193 - - [22/Dec/2012:07:01:00 +0000] "GET /test.php HTTP/1.0" 200 11000 "-" "ApacheBench/2.3"
118.144.94.193 - - [22/Dec/2012:07:01:00 +0000] "GET /test.php HTTP/1.0" 200 11000 "-" "ApacheBench/2.3"
118.144.94.193 - - [22/Dec/2012:07:01:01 +0000] "GET /test.php HTTP/1.0" 503 537 "-" "ApacheBench/2.3"
118.144.94.193 - - [22/Dec/2012:07:01:01 +0000] "GET /test.php HTTP/1.0" 503 537 "-" "ApacheBench/2.3"
118.144.94.193 - - [22/Dec/2012:07:01:01 +0000] "GET /test.php HTTP/1.0" 503 537 "-" "ApacheBench/2.3"
设置brust=1和nodelay后允许第1秒处理两个请求。
以上就介绍了php nginx限制ip请求次数 以及并发次数，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。
