Red Hat Topics - Help - SSH/FTP hanging on login

Author

Help - SSH/FTP hanging on login

ttsang123@gmail.com

2006-01-02, 7:46 am

Hi there,

I have an unusual problem and was looking for advice on where to look
for the answer.

I am managing a redhat 7.3 ES server and in the past few days I have
been having a problem logging into the server via ssh and ftp. I cannot
get beyond the username and password.

For example, when using SSH, I can get to the prompt for the username
and password, but after that it just hangs; it does not matter whether
the username is valid or not. The only way I can resolve it at the
moment is to reboot the server.

I have checked that the service is running, the /var/log/messages does
not appear to say anything out of the ordinary, neither has
/var/log/secure.

Also "ps faux" shows that ssh is running.

I have a firewall, but I have not touched that since the server went
live 9 months ago.

Lucky for me I have installed webmin so I can still acces the server.

Any advice, information or pointers would be gratefully received.

Thanks

Trevor

Greg Hackney

2006-01-02, 5:48 pm

You might try examining the packet activity on both ends to
see if it's a networking/firewall issue. For example:

tcpdump -i eth0 port 22

Otherwise, if you are really running 7.3: that's ancient and
hasn't been supported for a long time. There have been numerous
SSH bug fixes released since then.

If you can't updgrade the OS, then you might try compiling in the
latest www.openssh.org.

--
Greg

ttsang123@gmail.com wrote:
> Hi there,
>
> I have an unusual problem and was looking for advice on where to look
> for the answer.
>
> I am managing a redhat 7.3 ES server and in the past few days I have
> been having a problem logging into the server via ssh and ftp. I cannot
> get beyond the username and password.
>
> For example, when using SSH, I can get to the prompt for the username
> and password, but after that it just hangs; it does not matter whether
> the username is valid or not. The only way I can resolve it at the
> moment is to reboot the server.
>
> I have checked that the service is running, the /var/log/messages does
> not appear to say anything out of the ordinary, neither has
> /var/log/secure.
>
> Also "ps faux" shows that ssh is running.
>
> I have a firewall, but I have not touched that since the server went
> live 9 months ago.
>
> Lucky for me I have installed webmin so I can still acces the server.
>
> Any advice, information or pointers would be gratefully received.
>
> Thanks
>
> Trevor
>

pavlos

2006-01-02, 5:48 pm

You should be able to just restart ssh (service sshd restart)
and not reboot the server.

There may be some changes in the RSA keys. Check $USER/.ssh/ files
and you may have to edit the authorized_keys or known_hosts file.

HTH

ttsang123@gmail.com wrote:
> Hi there,
>
> I have an unusual problem and was looking for advice on where to look
> for the answer.
>
> I am managing a redhat 7.3 ES server and in the past few days I have
> been having a problem logging into the server via ssh and ftp. I cannot
> get beyond the username and password.
>
> For example, when using SSH, I can get to the prompt for the username
> and password, but after that it just hangs; it does not matter whether
> the username is valid or not. The only way I can resolve it at the
> moment is to reboot the server.
>
> I have checked that the service is running, the /var/log/messages does
> not appear to say anything out of the ordinary, neither has
> /var/log/secure.
>
> Also "ps faux" shows that ssh is running.
>
> I have a firewall, but I have not touched that since the server went
> live 9 months ago.
>
> Lucky for me I have installed webmin so I can still acces the server.
>
> Any advice, information or pointers would be gratefully received.
>
> Thanks
>
> Trevor
>

Kevin Collins

2006-01-03, 8:53 pm

In article <1136195312.965776.53970@f14g2000cwb.googlegroups.com>,
ttsang123@gmail.com wrote:
> Hi there,
>
> I have an unusual problem and was looking for advice on where to look
> for the answer.
>
> I am managing a redhat 7.3 ES server and in the past few days I have
> been having a problem logging into the server via ssh and ftp. I cannot
> get beyond the username and password.

What is "redhat 7.3 ES"? There is Redhat 7.3 and there is Redhat ES - they are
not the same thing...

> For example, when using SSH, I can get to the prompt for the username
> and password, but after that it just hangs; it does not matter whether
> the username is valid or not. The only way I can resolve it at the
> moment is to reboot the server.
>
> I have checked that the service is running, the /var/log/messages does
> not appear to say anything out of the ordinary, neither has
> /var/log/secure.
>
> Also "ps faux" shows that ssh is running.
>
> I have a firewall, but I have not touched that since the server went
> live 9 months ago.
>
> Lucky for me I have installed webmin so I can still acces the server.
>
> Any advice, information or pointers would be gratefully received.

Do you mean "ftp" or "sftp"? If you're unable to login with ssh/sftp then I
would suspect a problem with the the ssh subsystem.

If you really mean ssh and ftp, there is a bigger problem.

Does your system use NIS, NIS+ or LDAP to get user information? Do you have any
full filesystems (/var)? Did PAM somehow get broken? Is it all users or a
particular user (or group of users)? Can you login as root at the physical
console?

There are lots of possibilities - hopefully these ideas might help...

Kevin
--
Unix Guy Consulting, LLC
Unix and Linux Automation, Shell, PERL and CGI scripting
http://www.unix-guy.com