Re: strange routing / nat behavior

Alan Guo Wed, 07 Oct 2009 09:47:46 -0700

traceroute 一下, 看看到达北京和香港的路径有什么不一样.

BTW: 在你家里路由器上public ip是什么?


2009/10/7 Zhang Weiwu <[email protected]>

> 这个问题很奇怪的。我在兰州家中的电脑使用铁通拨号上网，modem后接了一台路由器（NAT防火墙），
> 路由器上接Linux主机。表现很奇怪。如果连接到北京的一台服务器上，用who命令显示自己IP地址
> 为123.138.24.244；如果连接到香港一台服务器上，用who命令显示自己IP地址为123.81.20.79。
>
> 如下：
>
>        zhangwe...@zhangweiwu-laptop:~$ ssh [email protected]
>        [email protected]'s password:
>        Linux casablanca 2.6.18.1-fl2f-v1.02 #41 Thu Jul 3 10:13:18 CST 2008
>        mips64
>
>        The programs included with the Debian GNU/Linux system are free
>        software;
>        the exact distribution terms for each program are described in the
>        individual files in /usr/share/doc/*/copyright.
>
>        Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
>        permitted by applicable law.
>        You have new mail.
>        Last login: Wed Oct  7 22:03:36 2009 from 123.138.24.244
>        zhangwe...@casablanca:~$ date; who
>        Wed Oct  7 22:09:06 CST 2009
>        zhangweiwu tty1         2009-09-23 20:53
>        zhangweiwu tty3         2009-09-24 08:49
>        zhangweiwu pts/6        2009-10-07 22:09 (123.138.24.244)
>        zhangwe...@casablanca:~$ logout
>        Connection to www.linuxbanks.cn closed.
>        zhangwe...@zhangweiwu-laptop:~$ ssh [email protected]
>        Enter passphrase for key '/home/zhangweiwu/.ssh/id_dsa':
>        Linux www.german-company-directory.com 2.6.18-6-686 #1 SMP Sun Feb
> 10
>        22:11:31 UTC 2008 i686
>
>        The programs included with the Debian GNU/Linux system are free
>        software;
>        the exact distribution terms for each program are described in the
>        individual files in /usr/share/doc/*/copyright.
>
>        Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
>        permitted by applicable law.
>        No mail.
>        Last login: Wed Oct  7 21:26:47 2009 from 123.116.123.210
>        rea...@www:~$ date; who
>        Wed Oct  7 21:29:40 CST 2009
>        realss   pts/0        2009-10-07 21:18 (123.116.123.210)
>        realss   pts/1        2009-10-07 21:29 (123.81.20.79)
>        rea...@www:~$ logout
>        Connection to www.german-company-directory.com closed.
>
> 这种情况，说明从兰州到北京经过了masquerade，到香港则没有。换言之如果在这个兰州
> 家中电脑上运行一个网站，香港人可以看到，大陆人看不到。实际使用nc试着做个“网站”
> 也证实了这个猜测。
>
> 问题一：这种奇怪的情况，有谁之前发现过？我在北京家中电脑上无法重现这个问题， 即如果北京家中电脑上运行一个网站，那么兰州和香港都能访问。
>
> 问题二：这种奇怪的设置有什么用意呢？我只能想到这样把国内的amule网络堵上了。
>



-- 
Alan Guo
http://bluestone.cublog.cn

Re: strange routing / nat behavior

回复