SSH clients periodically freeze under Windows 7

puttysshwindows 7

I am running Windows 7 Professional 64-bit. Two different SSH clients are exhibiting a strange habit of periodically freezing or hanging. I have tried both putty and Van Dyke's SecureCRT SSH clients and in both cases I will get a periodic freeze lasting anywhere from 20 seconds to a few minutes. No key strokes get through during the hang (not Ctrl-C, Ctrl-Z, or anything I have tried).

This happens while connecting to any of a number of servers. Others in my group using non-Windows machines do not seem to be having this problem. So, this is probably not a server-side issue.

I also use RDP to connect to Windows servers without similar freezes, so I don't think it is a networking issue with my machine.

Since this is happening with two different clients it seems like this must be a Windows issue.

Any suggestions?

UPDATE. Paying a little more attention, this only seems to happen when I am using emacs on the remote server. Since the freezing behavior only started when I moved from Windows XP to Windows 7 I attributed it to Windows, but maybe it is due to a more subtle interaction between emacs and Windows 7.

FURTHER UPDATE. My desktop support guy replaced the network cable and the problem seems to have gone away. I cannot explain why I noticed no network issues with my computer other than when working with Emacs through ssh. Perhaps there is something about using Emacs in this fashion that is particularly sensitive to network flakiness.

Best Answer

I use putty under windows and do not have this issue. There is nothing intrinsic to windows that would cause this issue. It could be something like symantec antivirus firewall or another piece of software that is interupting the connection.