Check if you are behind a transparent proxy

来源：互联网发布：知乎匿名的回答在哪里编辑：程序博客网时间：2024/05/22 07:44

文章出处：http://www.sajalkayan.com/check-if-you-are-behind-a-transparent-proxy.html

Many Asian ISPs do not provide clean internet. They route all HTTP sessions thru atransparent proxy.Here is a simple way to check if you are behind one.

sajal@sajal-laptop:~$ ping -c 4 www.cdnplanet.comPING www.cdnplanet.com (107.20.181.99) 56(84) bytes of data.64 bytes from ec2-107-20-181-99.compute-1.amazonaws.com (107.20.181.99): icmp_req=1 ttl=42 time=314 ms64 bytes from ec2-107-20-181-99.compute-1.amazonaws.com (107.20.181.99): icmp_req=2 ttl=42 time=313 ms64 bytes from ec2-107-20-181-99.compute-1.amazonaws.com (107.20.181.99): icmp_req=3 ttl=42 time=312 ms64 bytes from ec2-107-20-181-99.compute-1.amazonaws.com (107.20.181.99): icmp_req=4 ttl=42 time=312 ms--- www.cdnplanet.com ping statistics ---4 packets transmitted, 4 received, 0% packet loss, time 3004msrtt min/avg/max/mdev = 312.195/313.229/314.137/0.889 ms

sajal@sajal-laptop:~$ ab http://www.cdnplanet.com/This is ApacheBench, Version 2.3 <$Revision: 655654 $>Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/Licensed to The Apache Software Foundation, http://www.apache.org/Benchmarking www.cdnplanet.com (be patient).....doneServer Software:        ApacheServer Hostname:        www.cdnplanet.comServer Port:            80Document Path:          /Document Length:        13084 bytesConcurrency Level:      1Time taken for tests:   0.944 secondsComplete requests:      1Failed requests:        0Write errors:           0Total transferred:      13296 bytesHTML transferred:       13084 bytesRequests per second:    1.06 [#/sec] (mean)Time per request:       943.539 [ms] (mean)Time per request:       943.539 [ms] (mean, across all concurrent requests)Transfer rate:          13.76 [Kbytes/sec] receivedConnection Times (ms)              min  mean[+/-sd] median   maxConnect:       21   21   0.0     21      21Processing:   922  922   0.0    922     922Waiting:      611  611   0.0    611     611Total:        944  944   0.0    944     944sajal@sajal-laptop:~$

My ping time to CDN Planet is 312ms, but the connection was established in just 21ms !!!!11!!1Reasons for doing so involve : Censorship, big brother snooping, caching,hijacking users sessions , and probably more ...

上面内容为转载，以下通过实际的抓包来分析一下ab输出结果中最后一部分的含义：

测试中ab的实际输出为：

Connection Times (ms)              min  mean[+/-sd] median   maxConnect:      279  279   0.0    279     279Processing:   730  730   0.0    730     730Waiting:      259  259   0.0    259     259Total:       1009 1009   0.0   1009    1009

部分抓包截图如下：

。。。

分析可知，

Connect 279 ------ 三次握手的建立时间

Processing 730 ------ 从发送GET请求到接收完成的时间

Waiting 259 ------- 从发送GET请求到接收到第一个应答数据段的间隔

Total 1009 ------ Connect时间加上Processing时间

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