今天使用SSH連接vps，出現(xiàn)警示消息：

[feng@fsc ~]$ ssh root@v.path8.net
Address 173.245.70.75 maps to domain.not.configured, but this does not map back to the address -POSSIBLE BREAK-IN ATTEMPT!

上網(wǎng)查詢得到如下內(nèi)容http://blog.csdn.net/dingxy/archive/2008/05/05/2394900.aspx，好像是跟ip反解析有關，不影響ssh的使用，于是不過多管它。

今天在使用SCP的時候遇到個一個error,如下：
reverse mapping checking getaddrinfo for XXX.XXXX.com failed - POSSIBLE BREAKIN ATTEMPT!^M

我用ssh 連接了一下XXX.XXXX.com，同樣的問題
reverse mapping checking getaddrinfo for sXXX.XXXX.com failed - POSSIBLE BREAKIN ATTEMPT!
Last login: Mon May?0?2 5 16:50:08 2008 from 192.168.82.128

但是，還是能進入 XXX.XXXX.com。

找到以下解釋：

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.

當使用SSH或SFTP連接某個host時，會有一系列的檢查以保證你能夠連接到你想連接的機器。其中一項是 “reverse lookup on the IP address”檢查機器名稱和你要連接的機器名稱一致。否則，你會得到這樣一個錯誤信息："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 for192-168-1-243.foo.bar.net failed - POSSIBLE BREAK-IN ATTEMPT!
chris@my.example.com'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 reverseDNS 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).

這是告訴我們，盡管我們在連接my.example.com ，但是實際上該server的IP 地址對應到192-168-1-243.foo.bar.net 。但這個發(fā)生的時候，就是因為server 上的reverse DNS 沒有設置好。
舉例說，應該是把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?0?2 my.example.com，Now when I log in using SSH from the command line I won't get that error message any more.

這里有一個解決方法，修改ssh配置文件，讓這個消息不再顯示。

from http://iceskysl.1sters.com/?p=478

Get POSSIBLE BREAK-IN ATTEMPT msg when i ssh to s server

when i ssh to a server,i get some message like this：

Address 192.168.5.12 maps to localhost, but this does not map back to the address – POSSIBLE BREAKIN ATTEMPT!

Solution：

Modify the "/etc/ssh/ssh_config" file at localhost

GSSAPIAuthentication no

exp：

ssh 192.168.1.110時報錯上述錯，本地是192.168.1.20 ，則修改本地192.168.1.20中的/etc/ssh/ssh_config，把參數(shù)GSSAPIAuthentication no修改就可以了。。或者修改服務器端192.168.1.110上的/etc/ssh/sshd_config ，把參數(shù)GSSAPIAuthentication no改了也可以。要注意的是/etc/ssh/ssh_config和/etc/ssh/sshd_confg的區(qū)別。