since two days I am facing a really weird problem. I have receantly installed ubuntu server 14.04 LTS on a workstation. It has a fix IP address, which I can successfully ping from other computers in the network. But when I try to establish a ssh connection from a windows computer via putty I get some strange errors, which I cannot fix. The Problem is that putty takes a really long time trying to establish a connection. After about 10 seconds I get the following error:

Network error: Software caused connection abort

But when I click the Restart Session option a several times after putty shows the error message, I can login in. But now comes the other problem. When the login appears on the putty console I type in the user, but it really takes a long time until I can type in the password to login.

This is what I already tried:

• sshd: ALL in etc/hosts.allow
• commented line session optional pam_motd.so in etc/pam.d/login and etc/pam.d/sshd
• configured the firewall with: sudo iptables -A INPUT -p tcp --dport ssh -j ACCEPT
• checked if ssh server is listening on port 22
• UseDNS no in etc/ssh/sshd_config

I hope someone can help me, because this problem is really annoying. Thanks in regard