View Full Version : Help with Putty - "Network error: Software caused connection abort"

I have Putty installed at one of my work stations. It gives me this error roughly after 10-20 minutes of inactivity. I don't see any ping interruptions to the SSH server i am trying to hit. The ONLY settings i haven entered after a fresh reinstall have been

(Confidential Server name)

Port: 22

Connection type: SSH


1. Check for bad settings under "Session" And several other options in putty.

2. Complete reinstall of putty.

3. Spoke with my system administrators for anything wrong

4. Ran pings for when this interruption occurs. And i have a 0% Loss pinging the SSH Server.

In advance thank you all for your help!

To the best of my Knowledge it's just a unix server. I don't have the specifics about it though. I'm low enough in the chain to not have that information. But no one else in my department appears to have this issue.

Sounds like something on the server side honestly. Do you know what OS the server is running?

Have you tried connecting to any other servers through Putty before?

Are you behind any firewalls (especially software)?

The fact that this is happening after the connection has been idle for a while indicates you need to change the keepalive setting. In the left panel, click Connection, and check the setting for Sending of null packets to keep session alive. If it's set to 0, that setting is disabled. If it's set to 300 seconds, your firewall may be cutting off the connection after a minute or two because it assumes you are disconnected as putty is sending out null packets once every 5 minutes. Find out what the cutoff is and then make sure you are sending null packets before the cutoff deadline. Or, just set it to something like 5 seconds.

Come to think of it, I am behind a Sonicwall TZ170 (Firewall by dell) That is one defining Difference between myself and other people in my department. but i have been assured by sysadmin the settings are correct. And I have tried other servers But i am never using them long enough to see the problem i will try connecting them and see if i get the Disconnection error.