SSH tunnel with putty very slow

  • Hi!

    I use putty to create a SSH tunnel to the pfsense SSH server, to circumvent a restrictive firewall. It works good, but I get very slow speeds. Speed without tunnel is about 100/100 mb…but over the tunnel only 3/3 mb. Tested with Firefox, Chrome and WinSCP file transfers.

    Is there anything I can do to make it faster? Can the firewall be throttling ssh connections? I'm running a I5 5250U with 4GB ram. About 5% CPU load when i test, so hardware should not be the problem...? Also not using port 22.

    Best Regards


  • I've just tested this myself and I get great performance via a SSH port forward/tunnel.

    I'm using PuTTY to do my port forwarding under windows, you don't say what you're using. EDIT: Sorry, you say right there in the subject.

    Regardless, I don't think the problem is pfSense.  I have a similar machine, i5 5250U but my pfSense is virtualised on it, so it should be even slower theoretically.

    I would examine the following:

    • Client you're using (PuTTY etc)

    • TCPDump/Wireshark the connection and see if you're getting a lot of out of order TCP, or MTU problems

    It might also be that the restrictive firewall is limiting SSH traffic.

    Hope this helps (Though I realise how annoying "works for me!" posts are)

  • Thanks muppet. So it should be working better, good to get this confirmed. I suspect the firewall, but i will do some testing as you suggests. :)

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