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Polk
26th March 2009, 02:16
I'm getting this error in Putty:
Server unexpectedly closed network connection

Anyone knows how to fix it? All search results show to turn off UseDNS no but I'm not even using dns. I connect to IP directly. Anyway, tried that and it didn't work.

I'm able to connect from other locations. just one computer got blocked. I can't find anything in logs, tried to reinstall ssh, ssh-openserver, fail2ban.

I'm on Debian Lenny installed using Perfect Server manual.
falko
26th March 2009, 19:36
fail2ban
How many failed login attempts did you make from this computer? I guess fail2ban is blocking that computer.
Polk
26th March 2009, 19:48
How many failed login attempts did you make from this computer? I guess fail2ban is blocking that computer.


that's what I thought too. I did about 5 failed connections. I tried to uninstall fail2ban and also there was nothing in the iptables -L

Any ideas?
falko
27th March 2009, 15:32
http://debianclusters.cs.uni.edu/index.php/Fail2Ban:_Preventing_Brute_Force_SSH
Polk
27th March 2009, 17:48
Thank you. I found that link online too. And followed the steps. I did not have blocked IP in my list.
I also did apt-get remove fail2ban.
falko
28th March 2009, 20:26
And connecting from another IP works?
Is the IP listed in /etc/hosts.deny?
Polk
28th March 2009, 20:32
And connecting from another IP works?
Is the IP listed in /etc/hosts.deny?

Yes, I was able to connect from other IPs and yes, my blocked IP was listed there. Thank you so much! I removed and it's now working again!

Thank you!
sadnem
11th January 2010, 21:50
I post this just to inform people, my host was adding me automatically to /etc/hosts.deny so i had to erase my IP from /etc/hosts.deny and add it to /etc/hosts.allow I hope this can solve other people problems too ;)
darkbeat
6th March 2010, 19:00
hi im also having this problem when using smoothping putty.. can someon teach me how to fix it in much simplier instructions? hehe .. i already found tutorials on the web but sadly i find it really hard to understand T_T.. im using windows xp .. hope someone can help me
falko
7th March 2010, 16:05
Is your client IP listed in /etc/hosts.deny?

Have you tried to reboot the system?