SSH: connection reset after idle for some time

Because your last login was from comcast.net I am guessing that you are connecting from a home system where you are behind a router which is doing NAT. A problem that a system doing NAT has is knowing when the connection is no longer wanted. If the connection is taken down cleanly then there is no problem but if the two machines just reboot then there is no signal to the NAT box that this has happened. Therefore your typical NAT box has timers which say "if there is no traffic for an hour then the two endpoints clearly are not going to send anything more" and so recycles the resources that the NAT was taking.

So the thing to do is send some traffic every once in a while. The simplest way assuming you are using the openssh implementation on your cygwin machine is to enable TCPKeepAlive. replace

ssh [email protected]

with

ssh -o TCPKeepAlive=true [email protected]

For long term use you are better setting up a ~/.ssh/config file.

 host fred
     hostname host.com
     user root
     TCPKeepAlive=true

and then you will be able to say just ssh fred to connect to the machine with the needed option.