#!/bin/bash
#
# This program is used to keep a remote session alive by echoing nulls to a
# terminal after a minute of idle time.  Use if if you see
#   [root@unix root]# Read from remote host unix: Connection reset by peer
#   Connection to unix closed.
# after a short idle time.  This often happens when ssh is port forwarded
# through a firewall device.
#
# You will probably want to run this program in the background.  Don't forget
# to kill it before logging out!
#
# If you are on debian, you should use ssh's ProtocolKeepAlive setting.  This
# parameter is debian specific, the rest of us are still waiting for openssh
# to pick it up.
#
# If you have root access on either box, you can also do
# echo 60 >/proc/sys/net/ipv4/tcp_keepalive_time
# and the tcp keepalives will keep the connection open.
#

TTY=$(tty)
while true
do	find $TTY -mmin +1 | grep -q $TTY && echo -ne "\0"
	sleep 1
done