SSH issue ""Server unexpectedly closed network connection"

Errsta_Fonzarelli · 10-01-2005, 09:38 AM

Here's the deal:

OS: Debian (unstable)

I usually SSH into my home system remotely with no issues.

As of last night, when I attempt to log into the system with PuTTY, here's what happens: It prompts me for a user name and accepts it. It then prompts me for a password, and it then immediately aborts with the message:"Server unexpectedly closed network connection".

I checked /var/cache/apt/archives/ to see if my last upgrade included an ssh package. It did not.

/var/log/auth.log shows this message for each login attempt:

Code:

Sep 30 21:47:00 austin sshd[13203]: Accepted keyboard-interactive/pam for myusername from 13.16.61.31 port 29260 ssh2 

Sep 30 21:47:00 austin sshd[13208]: (pam_unix) session opened for user myusername by (uid=0) 

Sep 30 21:47:00 austin sshd[13208]: fatal: PAM: pam_setcred(): Critical error - immediate abort 

Sep 30 21:47:00 austin sshd[13208]: (pam_unix) session closed for user myusername

I checked my backup CD that I so wisely made a month ago and compared the /etc/ssh/sshd_config files and they are the same.

Any ideas?

wensveen · 10-01-2005, 11:59 AM

same problem here. got any further?

Errsta_Fonzarelli · 10-01-2005, 12:09 PM

yeah...

It was one of the libpam packages. Kinda wanted to keep them all at uniform revs, so I downgraded all of them.

libpam-cracklib_0.79-1_i386.deb
libpam-cracklib_0.79-2_i386.deb
libpam-modules_0.79-1_i386.deb
libpam-modules_0.79-2_i386.deb
libpam-runtime_0.79-1_all.deb
libpam-runtime_0.79-2_all.deb
libpam0g-dev_0.79-1_i386.deb
libpam0g-dev_0.79-2_i386.deb
libpam0g_0.79-1_i386.deb
libpam0g_0.79-2_i386.deb

I went down from the 0.79-2 versions back to the 0.79-1 versions and all is well...

unSpawn · 10-01-2005, 12:12 PM

If " touch /etc/environment" fixed that, then that was Bug#314289.

Errsta_Fonzarelli · 10-01-2005, 12:28 PM

Quote:

Originally posted by unSpawn
If " touch /etc/environment" fixed that, then that was Bug#314289.

Yes sir!

Thank you.

I went back up to the *79-2* revs and did the above. All is good now.

Thanks again!

wensveen · 10-02-2005, 04:32 PM

I didn't have a /etc/environment file but creating it did the trick. In which package is /etc/environment supposed to be?

Errsta_Fonzarelli · 10-02-2005, 04:55 PM

Quote:

Originally posted by wensveen
I didn't have a /etc/environment file but creating it did the trick. In which package is /etc/environment supposed to be?

FYI: "touch /etc/environment" creates the file

p_nyet · 01-13-2009, 03:04 AM

I have default sshd_config
UseDNS yes

and change UseDNS on sshd_config from "yes" to "no", restart sshd

CMIIW

Regards

pnyet.web.id

reddazz · 01-21-2009, 02:20 PM

p_nyet, welcome to the forum.

This is an old thread. If you would like to help, please can you look at new threads and assist if you can.

p_nyet · 01-22-2009, 04:39 AM

Quote:

Originally Posted by reddazz

p_nyet, welcome to the forum.

This is an old thread. If you would like to help, please can you look at new threads and assist if you can.

etapia · 03-02-2010, 08:51 PM

I had the same issue...I found that the IP of host I was trying to connect from was in /etc/hosts.deny

All I had to do is remove that entry

pocha · 05-24-2010, 03:24 PM

From another post, i figured out that by default, ubuntu puts ALL:ALL in hosts.deny file. So typically, the server would not be able to take any incoming http/ssh connection. You might like to remove the entry for the server to be able to take connections. Alternatively, you can selectively allow IPs in /etc/hosts.allow file.

fbsduser · 05-24-2010, 03:35 PM

The most likelly thing is that some updated package replaced your hosts.deny, hosts.allow, hosts.equiv, and hosts files with the default versions (of which the hosts.deny is set to ALL:ALL) what you have to do is that when you update packages you need to verify which config files it's replacing.