Reverse Mapping Checking - Possible Break-in Attempt Error with SSH

今天在使用SCP的时候遇到个一个error,如下：
reverse mapping checking getaddrinfo for XXX.XXXX.com failed - POSSIBLE BREAKIN ATTEMPT!^M

我用ssh 连接了一下 XXX.XXXX.com，同样的问题
reverse mapping checking getaddrinfo for s XXX.XXXX.com failed - POSSIBLE BREAKIN ATTEMPT!
Last login: Mon May  5 16:50:08 2008 from 192.168.82.128

但是，还是能进入 XXX.XXXX.com。

找到以下解释：

Reverse Mapping Checking - Possible Break-in Attempt Error with SSH
Posted May 2nd, 2008 in Linux/Unix/BSD

When you connect to a host using SSH or SFTP it does a series of checks to ensure you are connecting to the host you are expecting to connect to. One of these is a reverse lookup on the IP address to check the hostname is the same as the hostname you are connecting to. If it's not, you'll get an error message like "reverse mapping checking getaddrinfo for ... POSSIBLE BREAK-IN ATTEMPT!". The post looks at a solution to this message.

当使用SSH或SFTP连接某个host时，会有一系列的检查以保证你能够连接到你想连接的机器。其中一项是“reverse lookup on the IP address”检查机器名称和你要连接的机器名称一致。否则，你会得到这样一个错误信息："reverse mapping checking getaddrinfo for ... POSSIBLE BREAK-IN ATTEMPT!".

Connecting from the command line, you might enter something like this:

ssh my.example.comand get some output like this:

Connecting to my.example.com...reverse mapping checking getaddrinfo for 192-168-1-243.foo.bar.net failed - POSSIBLE BREAK-IN ATTEMPT!
[email protected]'s password:What this is telling us is that although we are connecting to my.example.com the IP address of the server we are connecting to actually maps back to 192-168-1-243.foo.bar.net in this example. When this actually happened to me, it's because the reverse DNS had not been set up for the server (which would map e.g. 192.168.1.243 to my.example.com as well as vice versa).

这是告诉我们，尽管我们在连接my.example.com ，但是实际上该server的IP 地址对应到192-168-1-243.foo.bar.net 。但这个发生的时候，就是因为server 上的reverse DNS 没有设置好。
举例说，应该是把192.168.1.243 映射到 my.example.com 。

Because I knew this reverse mapping was OK, I can add an entry to my hosts file and it will stop the error message from happening. For the above example, I would add the following to my hosts file:

192.168.1.243  my.example.com，Now when I log in using SSH from the command line I won't get that error message any more.