DragonFly users List (threaded) for 2007-06
Re: tty/pty/console wish
I will note one thing on remote sessions... if you are running through
NAT (network address translation), which is a very typical function of
today's cable modems, the NAT translation will often timeout if the
link stays idle too long. This will cause the link to die when you
come back to it later on and try to type something.
The only way to deal with this is to adjust the TCP keepalive timers:
The numbers are in ticks. The default, 7200000 (with hz = 100)
is 20 hours. That is, an idle TCP connection is only tested
once every 20 hours by default.
The keepalive interval is how often it retries (up to a limit) after
the tcp connection has been idle for keepidle ticks. The default is
around 12 minutes. It retries a few times before giving up and
dropping the connection.
You would have to reduce the idle interval down to something a lot
smaller to prevent the NAT session from timing out. Something like
60 seconds or so (keepidle set to 6000 and keepintvl set to 6000.
YMMV. Clearly not something one can do over a dialup or if running
a small server, but perhaps reasonable on a client. The interval
depends a lot on the NAT server and the connection load the NAT server