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ssh — usage, configuration and tips

SYNOPSIS

ssh [OPTION] REMOTE_HOST
  [COMMAND]

COMMAND LINE

options

-f	: fork
-L	: local forward
-D	: dynamic forward

x forwarding

does not work on slackware
ssh -X
trusted, works on debian/slackware
ssh -Y

TUNNEL

create

Example: This can be used to create a socks proxy for a browser.

ssh -f -D $PORT $SERVER sleep
  30000

D bindaddres:port / port (assumes localhost)
sleep 30000 : keep the connection alive with sleep command

connect through vpn on ssh tunnel

Example: If a SQL Server is only accesible in a different network, a tunnel can be created to access the SQL server through a computer that is accessible from outside that network.

commands

ssh -f -L
  127.0.0.1:$PORT:$TARGET_SERVER:$TARGET_PORT $SSH_SERVER_USR@$SSH_SERVER sleep
  30000

ssh -f -L
  127.0.0.1:1234:SQL_server:1433 user@ssh_server sleep 30000

: NOTE: on Microsoft SQL Server Studio use 127.0.0.1,1234

CONFIGURATION

To add configuration options for specific host:

$HOME/.ssh/config
Host hostname
	 [SSH OPTION]

example

This will always use port 8686 to connect to hostname:

Host hostname
	Port 8686

control master

: NOTE: The user needs to have write permissions in the directory where the socket will be created.

Create a persistent connection when connecting to a remote machine. Eg.:

ssh -f remote sleep 30

Host [HOST]
	ControlMaster auto
	ControlPersist yes
	ControlPath [PATH_TO_CONTROL_SOCKET]/%r@%h:%p

Commands

stop	\| stop accepting requests.
exit	\| exit master.
cancel	\| cancel forwardings.
forward	\| request forwardings.
proxy	\| connect to master in proxy mode.

SSH KEYS

ssh-keygen

Copy the resulting pub contents to the corresponding Host.

TODO

Review -L.
Add better examples.

AUTHORS

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