ubuntu ssh命令错误

SSH登陆错误 WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!
[root@localhost ~]# ssh 192.168.10.88
@    WARNING:
REMOTE HOST IDENTIFICATION HAS
CHANGED!   
@ 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
b6:0c:41:43:60:79:eb:05:9e:c9:72:1d:a0:41:9a:50.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this
message.
Offending key in /root/.ssh/known_hosts:5
RSA host key for 192.168.10.88 has changed and you have requested
strict checking.
Host key verification failed.
因为在本地机器上曾经用SSH登录过这台远程计算机，因而留下了known_hosts的记录，在远程计算机重新安装系统后不能够通过鉴权.gedit ~/.ssh/known_hosts 进入此目录，删除192.168.10.88的相关rsa的信息即可.
二、The authenticity of host '192.168.2.108 (192.168.2.108)' can't be
established.
wzhnsc@wzhnsc-Ubuntu:~$ ssh 192.168.2.108
The authenticity of host
'192.168.2.108 (192.168.2.108)' can't be established.
DSA key fingerprint is
bb:43:0c:db:43:46:7e:5d:a1:6e:34:b4:fc:37:38:10.
Are you sure you want to continue connecting (yes/no)? y
Please type 'yes' or 'no': y
Please type 'yes' or 'no': y
Please type 'yes' or 'no': yes
Warning: Permanently added '192.168.2.108' (DSA) to the list of
known hosts.
Password:
Password:
Password:
出现上面的情况，只好按ctrl + c退出来了！
解决办法： ssh -l 有效用户名
服务器的IP地址
wzhnsc@wzhnsc-Ubuntu:~$ ssh -l root
192.168.2.108
Password:
Last login: Tue Dec 29 16:12:38 2009 from 192.168.2.118
Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994
    The Regents
of the University of California.  All rights
reserved. FreeBSD 7.0-RELEASE (GENERIC) #0: Sun Feb 24 19:59:52 UTC
2008 Welcome to FreeBSD!
Before seeking technical support, please use the following
resources:
o  Security advisories and updated errata
information for all releases are
   at
http://www.FreeBSD.org/releases/ - always consult the ERRATA
section
   for your release first as it's
updated frequently.
o  The Handbook and FAQ documents are at
http://www.FreeBSD.org/ and,
   along with the mailing lists,
can be searched by going to
 
http://www.FreeBSD.org/search/.  If the doc
distribution has
   been installed, they're also
available formatted in /usr/share/doc.
If you still have a question or problem, please take the output
of
`uname -a', along with any relevant error messages, and email
it
as a question to the [email protected] mailing
list.  If you are
unfamiliar with FreeBSD's directory layout, please refer to the
hier(7)
manual page.  If you are not familiar with manual
pages, type `man man'.
You may also use sysinstall(8) to re-enter the installation
and
configuration utility.  Edit /etc/motd to change
this login announcement.
FreeBSD#