Hi Hari,
In Putty you can set a keep-alive setting (under Connection in the
settings), I set mine to 60 seconds and this prevents most dropped
connections.
Nathalie
Hari Sekhon wrote:
Hi,
I have a remote worker who uses SSH tunneling to connect into the
office while on the road. He is running Windows with PuTTY connecting
to a Linux OpenSSH server. He has been reporting that it is extremely
unstable and that the connection drops. However, I and a colleague of
mine use this method regularly and have had no problems.
I suspect that this is simply due to his use of a 3G card which has a
very slow dial-up speed connection, whereas myself and my colleague
have broadband (actually it does drop more when my internet pipe is
flooded).
Is there anything I can do to make the connection more tolerant and
not drop?
Or perhaps any advice for further isolating this (bearing in mind the
remote worker is not technical and I don't have access to the laptop
at the times he's on the road...)
This same remote worker was previously using an ipsec vpn with 3des
and had no problems so I suspect that 3des is more forgiving that the
ssh protocol(s) being used for cryptography, although I am aware that
ssh can use several different crypto algorithms, and reading the man
page again it seems that 3des is the default on linux but PuTTY seems
to default to AES first so perhaps it is AES being less forgiving that
3des?
Does anyone know more about the actual AES and 3DES protocol
internals, is AES less tolerant to timing issues because of it's
stronger cryptography (sort of like Kerberos system times being used
in the crypto algorithm)?
Any ideas or feedback on this issue?
Thanks
-h
