linux as4u5,远程拒绝连接，高手在哪里？

xp1223

LINUX AS 4 UPDATE 5系统，开了防火墙，接在一台CISCO PIX515上，SSH端口是22，TELNET端口是7809。这些端口都是开了的，系统开始运行的时候SSH,TELNET都是可以远程登陆的，系统运行一段时间后远程连接就不行了，SSH,TELNET都不行，重启过。
PORT   STATE SERVICE
22/tcp open  ssh

系统是可以PING通的，还有一台生产系统也连在CISCO PIX 515 上，没有任何问题。机器和防火墙的配置没有做任何改变。有谁遇到过这种问题？问了N个玩LINUX的，都无解，郁闷ｉｎｇ．．．．．．．．．．．

coldrainsunc

ssh -vv ip
有输出吗？

ssffzz1

是LINUX开的22端口还是PIX开的端口

xp1223

linux 开的端口

xp1223

ssh -vv ip输出如下结果：


IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
5a:70:b8:24:b0:1f:66:c9:d7:36:69:94:ab:1d:8c:54.
Please contact your system administrator.
Add correct host key in /home/probe/.ssh/known_hosts to get rid of this message.
Offending key in /home/probe/.ssh/known_hosts:1
RSA host key for x.x.x.x has changed and you have requested strict checking.
Host key verification failed.

ssffzz1

首先你看了日志了吗？
其次，无法连接的时候能够ping通吗？

5iwww

service iptables stop 试试

xp1223

现在看不到日志，系统在运行，是可以PING通的。主机和防火墙是没有动的，是之前都是好的，就是突然就连不上。

ssffzz1

从以下几个方面入手：
1、查看出错时的日志。
2、当SSH不通是能够PING通，延迟如何。
3、出现故障是否有规律，如间隔时间，或者某一个特殊时间发生。
4、关闭防火墙，SELINUX，还有ACPI服务，电源中关闭ACPI支持。

xp1223

很感谢各位的回复，问题和防火墙和端口的可能行不大，应该是这里：
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
5a:70:b8:24:b0:1f:66:c9:d7:36:69:94:ab:1d:8c:54.
Please contact your system administrator.
Add correct host key in /home/probe/.ssh/known_hosts to get rid of this message.
Offending key in /home/probe/.ssh/known_hosts:1
RSA host key for x.x.x.x has changed and you have requested strict checking.
Host key verification failed.

貌似密钥认证出错？