Bruno Flueckiger wrote:
> Hi Alex
>
> On 2006-10-16, Alex <alexqua@gmail.com> wrote:
>
>> I setup a connection to a server behind a firewall using the tunnel
>> function in putty (v. 0.56).
>> Even though the number of seconds between keepalive has been set to 60,
>> after some minutes of idle the connection is dropped.
>> Does anyone know if there's a way to forward keepalive packets to the
>> target host with putty?
>
> Have you enabled the option "Enable TCP keepalives" in PuTTY? It is
> right under field you enter seconds between keepalives. Maybe this will
> keep your connection running.
>
> Another possibility is to check the configuration of the SSH daemon. The
> ssh daemon supports two sorts of keep alive messages: TCP keepalive
> messages and SSH specific alive messages. For details about this options
> please check the following paragraphs in sshd_config(5):
>
> ClientAliveCountMax
> ClientAliveInterval
> TCPKeepAlive
>
> The enabling of one or both of these keep alive messages may solve
> your problem.
>
> HTH,
> Bruno
>

Also might want to consider upgrading to 0.58. 0.56 had some security
issue. There have also been numerous bug fixes between the releases.