Something weird I've noticed since upgrading my office router to the Buffalo WZR-HP-G300NH. When I remote in using an SSH tunnel, the tunnel will "freeze" pretty often. The freeze lasts 1-2 minutes each, after which all the traffic that was stuck catches up. It's very annoying to be using VNC and have the session pause every few minutes.
I am using the following command from my local machine:
ssh -D 9000 firstname.lastname@example.org
I know the whole router isn't freezing because I can open another SSH session and it's fine -- until it freezes, too. The freezing sessions are independent of each other. Both will periodically freeze, but not at the same time.
I can start a ping going in both sessions and neither loses a single packet or even shows any lag, even though the both freeze a couple times.
If I forward the VNC port straight through to the remote machine, the problem gets somewhat better leading me to believe this is more likely a TCP issue rather than SSH. But I'm not ruling anything out.
This behavior has persisted despite upgrading firmwares to the latest dd-wrt, including the build that was pulled a few weeks ago.
Is it a problem with dropbear? Or with MTU? QoS?