Portal Home > Knowledgebase > Articles Database > SSH tunneling could be so much better
Posted by web-1, 08-30-2012, 11:28 AM The problem with SSH tunneling is that it's TCP over TCP and they say that causes problems. If you lose a packet at the "base" level, it retries packets inside the second level and gets absolutely nothing back because the base level (outside network / internet part) is doing it's own retries. So it's stuck. It takes a while for it to figure it all out and you are sitting there looking silly till it does whatever it does to get un-stuck. But here's the thing, while it is stuck you can still hit the return key in your terminal where your SSH tunnel is running and you can see packets go out to the server and then a response come back. Meaning that SSH is actually still responding just fine and the base level connection is still working. If you hold the return key long enough (repeating) you exceed some kind of buffer limit in SSH and it will then do something ( possibly a TCP reset packet is FINALLY sent ? ) and all of a sudden your tunnel starts working again. Which leads me to think that if SSH had a little extra code to watch the connection and send a TCP reset (or whatever it does) when needed, it wouldn't get stuck so much. Try this next time you get stuck and see if it works for you.
Add to Favourites 
Print this Article
