Corregir SSH Concection refused

Cuando nos conectamos de un sistema linux a otro a través de SSH este guarda un registro de la conexión y si cambiamos, por lo que sea, nuestra IP, podriamos encontrarnos con un error algo asi

zeth@m9351:~$ ssh 192.168.0.101

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

@ @ 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 a host key has just been changed.

The fingerprint for the RSA key sent by the remote host is

4a:38:09:ff:64:c2:09:2d:2c:61:dd:30:1d:46:46:3f.

Please contact your system administrator.

Add correct host key in /home/zeth/.ssh/known_hosts to get rid of this message.

Offending RSA key in /home/zeth/.ssh/known_hosts:7

remove with: ssh-keygen -f "/home/zeth/.ssh/known_hosts" -R 192.168.0.101

RSA host key for 192.168.0.101 has changed and you have requested strict checking.

Host key verification failed.

A primera vista espanta, luego, nos damos cuenta que no es tan complicado, sin mayor rodeo, para solucionarlo procedemos primero a hacernos superusuarios

zeth@m9351:$ sudo su

[sudo] password for zeth: ****************

root@m9351:#

nos movemos al directorio de SSH y listamos su contenido

root@m9351:~# cd /etc/ssh

root@m9351:/etc/ssh# ls

Dentro de este direcorio encontraremos el fichero “ssh_host_rsa_key” el cual, y para evitar posibles errores respaldaremos

root@m9351:/etc/ssh# cp ssh_host_rsa_key ssh_host_rsa_key.orig

y procedemos a editar el fichero original (yo uso el editor vim, es igual usar nano o gedit o el que mas te guste)

root@m9351:/etc/ssh# vim ssh_host_rsa_key

Quitamos todo lo que este entre las cabeceras del archivo

-----BEGIN RSA PRIVATE KEY-----

MIIEpQIBAAKCAQEA13aLueccpFziqEtB1sdlrPC8pZG/SRSf6dJNt+7Gc/Md5hGm

hfmxdhD13ZpEt+gr/Ooo1/RMJTENgiaQfiOMqwhLqAm3jy9mzoQBGsOKwBBBnMcs

jCFcy/0LHy1333i9f4XdlEwrXCVZxUpD/JUunRcxb0yIAXGlA9n2w5d0rOPxkZaL

+lOBnzZN8VQZrNP8SZFvCSqYit5aHOWn+c+JhKBs46rFq2NV8pgNtiZ7O1dDXFkL

F6lLlJzW12CZYh5z8HPYrOWnEeATmNWuid0PRmOiEf1w8tBicxt0GxXEfK7HZ+dS

yqRTvDcrbFJXMH2RTkZu43CS4u8ZJKRHCz261wIDAQABAoIBAQCjqatnEbNC8j9E

4K1pLNsBq3dQOM5Y/66cmJ9qSJg7+P7MBLo96DWxXh60LntmSpgnK+LMbwfr9D+z

jgGRnwU54To+sOrae4IW+lQwdToOvApqwSwIYUsws8xf6VS1zev7Ur7F57nD66ct

4kSUNulKcBSf2z0wA5f5vfXgCkqZC8JLR2leriGsuluqfP8gAjeMpaNKcw5zB1kS

7y6D71vDnA+XYkiR5CmaUAuyVI2HVNmccM/P64dzRTJJxrF0RAMGaTrGHcOMMgB6

TTTbjC8fKd11BiSCz7n/TFZIietTKAw8uVdMCCfH0lNCsSt9Mpn0tD1GsxefU4mc

Ae+xi6jxAoGBAP4Vq9TcElVu53oOrhq+f41VJpOG0LC5O7n0uT1rUVbE932A5h53

bv/CPPGdHnRb2E/VHOukeprKM+1Cg7M3P4PJ2hlJ1eG6BubrUCui4l5h6+1qJQyD

0HIsC8Z/VAAhSLUdygAZbOHNCDrPwQzrNA2u5Dnki38bkiHtqvtXxiI/AoGBANkW

V94AFgEi3s5Y/ry54SPqbf6lyVrXXsZNfyL2N+QlNdGT1Bir/hwtxBBAqyyVcQ0k

RRsEuW8Z4Qn20AlVDscKDZjx3zOSyLMWH0GuTvVFU72mhpUREgFYckcmP8pZAWov

zBoU2HQMShzRD2osSKOeKKBTW+DRwA6sEPfhbJFpAoGBAMVLfJ8Pt+jA8lsz1PuN

WqwbJ5Y8hAYF/5u4rLJFh+ZxkZ/RnF6h7P4KDJqsnz5JJyFuYUOU92MEiee801kx

GE+0SHeEfuEFO2DJ7fnERDR3ouQ6nMQoAo71JruemVJ0hemlVPpYw9ReCfro4YWv

iT7qw+s0TSGI/iL8Ut1SXdavAoGATmzf+XeWe3qZe3pzLMMKLut2KVTDVWoQ9xrw

HzVMI8O9maUKLo+UEaIG/sgeDtE+Mj00Kfqe8yAqSGs95OExoX5kQyi+NeeFUg1f

5V6Pb9RH2G/cluW/13SYdFPBH9zfwfjah2GYgPQfoiF0rCqrY1Cz5Je4zZN5CtPm

nWZ2zmECgYEA5W/lQfoW0g0WsY/2+3F4zLnLwbl586vNqWqzW9YpFM7VWTlcHqwP

jaRGeHYbqL9MVMAqthoy33rOW/XQclf/VZ6hwiw8lcWH+XGf0gFmlPgzOvRcwgkl

kXU4AuTTrKMPztvUVZ0BOZxYkkIfFqNIkLCYZIORnzMVjwsh82rS/zY=

-----END RSA PRIVATE KEY-----

Lo dejamos así y guardamos

-----BEGIN RSA PRIVATE KEY-----

-----END RSA PRIVATE KEY-----

Nota: importante dejar la linea en blanco entre Begin y End

Y volvemos a Intentar

root@m9351:/etc/ssh# ssh 192.168.0.101

The authenticity of host '192.168.0.101 (192.168.0.101)' can't be established.

RSA key fingerprint is 4a:38:09:ff:64:c2:09:2d:2c:61:dd:30:1d:46:46:3f.

Are you sure you want to continue connecting (yes/no)? yes

Warning: Permanently added '192.168.0.101' (RSA) to the list of known hosts.

root@192.168.0.101's password:

Last login: Fri Feb 22 22:54:51 2013 from 192.168.0.108

[root@sisvir305 ~]#

Fin