명령어는 ssh와 같은 option을 가지며 -M 만 추가되어 있다. sshforward라는 script를 만들고 update-rc.d 명령을 사용하여 boot script에 등록한다.
update-rc.d sshforward defaults
sshforward는 아래와 같이 구성되어 있다. .
#! /bin/sh
set -e
export PATH="${PATH:+$PATH:}/usr/sbin:/sbin"
case "$1" in
start)
echo -n "Starting Port(22) forwarding to home.jmjeong.com "
start-stop-daemon -b -m -c jmjeong --start --quiet --pidfile /var/run/sshforward.pid --exec /usr/bin/autossh -- -M 29001 -R 8275:localhost:22 jmjeong@home.jmjeong.com -N -p 8022
echo "."
;;
stop)
echo -n "Stopping Port(22) forwarding to home.jmjeong.com"
start-stop-daemon -c jmjeong --stop --quiet --oknodo --pidfile /var/run/sshforward.pid
echo "."
;;
*)
echo "Usage: /etc/init.d/sshforward {start|stop}"
exit 1
esac
exit 0
-R [bind_address:]port:host:hostport
Specifies that the given port on the remote (server) host is to be forwarded to the given host and port on the local side. This works by allocating a socket to listen to port on the remote side, and whenever a connection is made to this port, the connection is forwarded over the secure channel, and a connection is made to host port hostport from the local machine.
Port forwardings can also be specified in the configuration file. Privileged ports can be forwarded only when logging in as root on the remote machine. IPv6 addresses can be specified by enclosing the address in square braces or using an alternative syntax: bind_address/host/port/hostport.
By default, the listening socket on the server will be bound to the loopback interface only. This may be overriden by specifying a bind_address. An empty bind_address, or the address '*', indicates that the remote socket should listen on all interfaces. Specifying a remote bind_address will only succeed if the server's GatewayPorts option is enabled (see sshd_config(5)).