SSH Port Forwarding - Revision history

Graggle at 23:59, 20 April 2026

2026-04-20T23:59:30Z

← Older revision		Revision as of 23:59, 20 April 2026
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	{{Outdated}}		{{Outdated}}


	==Why?==		==Why?==

Graggle at 23:59, 20 April 2026

2026-04-20T23:59:23Z

← Older revision		Revision as of 23:59, 20 April 2026
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			{{Outdated}}

	==Why?==		==Why?==
	One example of why port forwarding is great is security. Downloading email and browsing the Internet in such a way that the immediate (local) network does not know what you are doing. All it sees is encrypted SSH traffic, like that used when you type on RedBrick normally.		One example of why port forwarding is great is security. Downloading email and browsing the Internet in such a way that the immediate (local) network does not know what you are doing. All it sees is encrypted SSH traffic, like that used when you type on RedBrick normally.

Graggle: Graggle moved page How-To:Port Forwarding to SSH Port Forwarding: more relevant title

2026-04-20T23:42:53Z

Graggle moved page How-To:Port Forwarding to SSH Port Forwarding: more relevant title

← Older revision	Revision as of 23:42, 20 April 2026
(No difference)

D fens at 16:12, 30 September 2016

2016-09-30T16:12:41Z

← Older revision		Revision as of 16:12, 30 September 2016
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	remote port: 6667		remote port: 6667

	So for this it is instead using a local forward. So unlike the dynamic forward, instead set the option to be local, and add the ~~remote address~~ as being irc.redbrick.dcu.ie:6667		So for this it is instead using a local forward. So unlike the dynamic forward, instead set the option to be local, and add the destination as being irc.redbrick.dcu.ie:6667

	On CLI this is:		On CLI this is:

D fens at 16:08, 30 September 2016

2016-09-30T16:08:41Z

← Older revision		Revision as of 16:08, 30 September 2016
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	Where :		Where :
	* -L specifies you want to link a ~~local~~ port		* -D specifies you want to link a dynamic port
	* 1337 is the local port (on your machine) you want to communicate on.		* 1337 is the local port (on your machine) you want to communicate on.
	* proxy.dcu.ie is the server you want to send your tunnelled traffic to.
	* 3128 is the port on that server you want to send your tunnelled traffic to.
	* login.redbrick.dcu.ie is the server you want to open the SSH connection to		* login.redbrick.dcu.ie is the server you want to open the SSH connection to


	~~[[Image:Tunnelling-network-diagram.png]]~~

	~~For example, to tunnel local port 1337 to the SOCKS proxy on proxy3.dcu.ie through deathray:~~
	~~ssh -L 1337:proxy3.dcu.ie:1080 login.redbrick.dcu.ie~~

	~~Here we see that we specify the proxy definitively, and use the port that we~~
	~~would eventually negotiate (for those of you is res try running Wireshark, you will~~
	~~see what I mean). We also use a specific Redbrick server, Login (minerva) for our port~~
	forwarding (there are restrictions on tunnelling through our other machines). You can also add the ''-v'' option to specify 'verbose' mode and see the port being opened and closed for your tunnelled traffic.

	~~Try running netstat locally and and you should see 1337 sitting there happily.~~
	~~So now you have it all set up, congratulations! Now, how do you use it? Easy!~~
	~~Open up your browser and change the proxy settings to localhost:1337, you~~
	~~will then be using the local port to forward traffic to the DCU proxy, the same~~
	~~applies to your mail program.~~

	~~Note this only encrypts your traffic to and from Redbrick, so anyone listening~~
	~~on the wifi hotspot you are using will just see garbage going to DCU (figures),~~
	~~anyone listening to DCU traffic from the proxy can still see you stuff, the moral~~
	~~being â€don't go downloading donkey pornâ€ DCU will still be out to get you, etc.~~
	~~So, thats it, enjoy you new found 1337ness.~~

	~~niT.~~

	==Port forwarding for IRC==		==Port forwarding for IRC==

	~~Since ircproxy is offline, and will probably remain so (it was fairly shite anyway), if~~ you want to connect to RedBrick IRC with your own client you will need to use port forwarding to do this.		If you want to connect to RedBrick IRC with your own client you will need to use port forwarding to do this.

	The process is the same as the above, just using different addresses and port configurations.		The process is the same as the above, just using different addresses and port configurations.
Line 79:		Line 52:
	remote port: 6667		remote port: 6667

	So, ~~you're basically substituting 1337 and 3128 for 6667~~, and ~~proxy3~~.dcu.ie ~~for~~ irc.redbrick.dcu.ie.		So for this it is instead using a local forward. So unlike the dynamic forward, instead set the option to be local, and add the remote address as being irc.redbrick.dcu.ie:6667

			On CLI this is:

			ssh -L 6667:irc.redbrick.dcu.ie:6667 username@login.redbrick.dcu.ie

	Now, just tell your ~~irc~~ client that your ~~irc~~ server is localhost :)		Now, just tell your IRC client that your IRC server is localhost :)

	[[Category:HowTo]]		[[Category:HowTo]]

D fens: update images to align and be less crappy looking

2016-09-30T16:05:34Z

update images to align and be less crappy looking

← Older revision		Revision as of 16:05, 30 September 2016
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	** Source port: (the port you want forwarded to the proxy - eg 1337)		** Source port: (the port you want forwarded to the proxy - eg 1337)
	** Destination: <blank>		** Destination: <blank>
	* Ensure Dynamic is selected as the type and then click Add		* Ensure Dynamic is selected as the type and '''then click Add'''

	[[Image:Proxy_putty.png]]		[[Image:Proxy_putty.png\|center\|frame\|How to configure PuTTY to be a SOCKS proxy]]

	* Click the Open button to connect, and enter your username/password.		* Click the Open button to connect, and enter your username/password.
	* Tell Firefox (or anything else) to use localhost 1337 as its HTTP proxy. You should now be browsing via RedBrick!		* Tell Firefox (or anything else) to use localhost 1337 as its HTTP proxy. You should now be browsing via RedBrick!

	[[Image:Http_proxy.png]]		[[Image:Http_proxy.png\|center\|frame\|How to configure Firefox to use PuTTYs proxy]]

	'''OpenSSH for Windows'''		'''OpenSSH for Windows'''

D fens at 16:00, 30 September 2016

2016-09-30T16:00:08Z

← Older revision		Revision as of 16:00, 30 September 2016
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	* Ensure Dynamic is selected as the type and then click Add		* Ensure Dynamic is selected as the type and then click Add

	[[Image:~~puttyconf~~.png]]		[[Image:Proxy_putty.png]]

	* Click the Open button to connect, and enter your username/password.		* Click the Open button to connect, and enter your username/password.
	* Tell Firefox (or anything else) to use localhost 1337 as its HTTP proxy. You should now be browsing via RedBrick!		* Tell Firefox (or anything else) to use localhost 1337 as its HTTP proxy. You should now be browsing via RedBrick!

			[[Image:Http_proxy.png]]

	'''OpenSSH for Windows'''		'''OpenSSH for Windows'''

D fens at 15:58, 30 September 2016

2016-09-30T15:58:52Z

← Older revision		Revision as of 15:58, 30 September 2016
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	~~(Submitted by [[User:nit\|nit]], pasted & edited by [[User:Igy\|igy]])~~

	==Why?==		==Why?==
	One example of why port forwarding is great is security.		One example of why port forwarding is great is security. Downloading email and browsing the Internet in such a way that the immediate (local) network does not know what you are doing. All it sees is encrypted SSH traffic, like that used when you type on RedBrick normally.
	Downloading email and browsing the Internet in such a way that the immediate (local) network does not know what you are doing. All it sees is encrypted SSH traffic, like that used when you type on [RedBrick] normally.

	~~Thus you can (a little more) securely access your stuff from wireless hotspots~~
	~~or from other insecure or filtered networks~~.

	The example being given is to use your ~~redbrick~~ account to port forward data ~~to the~~		The example being given is to use your Redbrick account to port forward data via Redbrick. You can then configure local applications to use the tunnel rather than the usual route over say insecure wireless or hotel wifi thereby hopefully securing your data in transit.
	~~dcu proxy~~. You can then configure local applications to use the tunnel
	rather than the usual route.

	==Theory==		==Theory==
	~~One good online guide is: http~~://~~neworder~~.~~box~~.sk/~~newsread.php?newsid=12498~~		There are some [https://help.ubuntu.com/community/SSH/OpenSSH/PortForwarding good online guides] and if you read this you should be able to deduce the basics of how SSH works with port forwarding.
	and if you read this you should be able to deduce the basics of how SSH works with port forwarding.

	==How To do it==		==How To do it==
Line 24:		Line 15:

	[[PuTTY]] has built-in support for port forwarding.		[[PuTTY]] has built-in support for port forwarding.
	* When you're connecting, after you've filled in the host name box ('''NOTE:''' If you wish to forward traffic through the ~~DCU proxy~~ the host name '''must''' be login.redbrick.dcu.ie), click on Tunnels in the left-hand bar (second last item from the bottom).		* When you're connecting, after you've filled in the host name box ('''NOTE:''' If you wish to forward traffic through the RedBrick the host name '''must''' be login.redbrick.dcu.ie), click on Tunnels in the left-hand bar (second last item from the bottom).
	* In the Port forwarding box, fill in the following values:		* In the Port forwarding box, fill in the following values:
	** Source port: (the port you want forwarded to the proxy - eg 1337)		** Source port: (the port you want forwarded to the proxy - eg 1337)
	** Destination: ~~proxy.dcu.ie:3128~~		** Destination: <blank>
	* Ensure ~~Local~~ is selected as the type and then click Add		* Ensure Dynamic is selected as the type and then click Add

	[[Image:puttyconf.png]]		[[Image:puttyconf.png]]

	* Click the Open button to connect, and enter your username/password.		* Click the Open button to connect, and enter your username/password.
	* Tell Firefox (or anything else) to use localhost:1337 as its HTTP proxy. You should now be browsing via ~~DCU's proxy server~~!		* Tell Firefox (or anything else) to use localhost 1337 as its HTTP proxy. You should now be browsing via RedBrick!

	'''OpenSSH for Windows'''		'''OpenSSH for Windows'''
Line 42:		Line 33:

	If you read the neworder guide above you should have a good idea of how to build the SSH command for the forwarding, like so:		If you read the neworder guide above you should have a good idea of how to build the SSH command for the forwarding, like so:
	ssh -L 1337~~:proxy.dcu.ie:3128~~ login.redbrick.dcu.ie		ssh -D 1337 username@login.redbrick.dcu.ie

	Where :		Where :

Dregin at 19:33, 8 December 2010

2010-12-08T19:33:04Z

Receive: removed deathray references

2008-10-12T14:00:00Z

removed deathray references

← Older revision		Revision as of 19:33, 8 December 2010
Line 24:		Line 24:

	[[PuTTY]] has built-in support for port forwarding.		[[PuTTY]] has built-in support for port forwarding.
	* When you're connecting, after you've filled in the host name box ('''NOTE:''' If you wish to forward traffic through the DCU proxy the host name '''must''' be ~~carbon~~.redbrick.dcu.ie), click on Tunnels in the left-hand bar (second last item from the bottom).		* When you're connecting, after you've filled in the host name box ('''NOTE:''' If you wish to forward traffic through the DCU proxy the host name '''must''' be login.redbrick.dcu.ie), click on Tunnels in the left-hand bar (second last item from the bottom).
	* In the Port forwarding box, fill in the following values:		* In the Port forwarding box, fill in the following values:
	** Source port: (the port you want forwarded to the proxy - eg 1337)		** Source port: (the port you want forwarded to the proxy - eg 1337)
Line 42:		Line 42:

	If you read the neworder guide above you should have a good idea of how to build the SSH command for the forwarding, like so:		If you read the neworder guide above you should have a good idea of how to build the SSH command for the forwarding, like so:
	ssh -L 1337:proxy.dcu.ie:3128 ~~carbon~~.redbrick.dcu.ie		ssh -L 1337:proxy.dcu.ie:3128 login.redbrick.dcu.ie

	Where :		Where :
Line 49:		Line 49:
	* proxy.dcu.ie is the server you want to send your tunnelled traffic to.		* proxy.dcu.ie is the server you want to send your tunnelled traffic to.
	* 3128 is the port on that server you want to send your tunnelled traffic to.		* 3128 is the port on that server you want to send your tunnelled traffic to.
	* ~~carbon~~.redbrick.dcu.ie is the server you want to open the SSH connection to		* login.redbrick.dcu.ie is the server you want to open the SSH connection to


Line 55:		Line 55:

	For example, to tunnel local port 1337 to the SOCKS proxy on proxy3.dcu.ie through deathray:		For example, to tunnel local port 1337 to the SOCKS proxy on proxy3.dcu.ie through deathray:
	ssh -L 1337:proxy3.dcu.ie:1080 ~~carbon~~.redbrick.dcu.ie		ssh -L 1337:proxy3.dcu.ie:1080 login.redbrick.dcu.ie

	Here we see that we specify the proxy definitively, and use the port that we		Here we see that we specify the proxy definitively, and use the port that we
	would eventually negotiate (for those of you is res try running Wireshark, you will		would eventually negotiate (for those of you is res try running Wireshark, you will
	see what I mean). We also use a specific Redbrick server, ~~Carbon~~ for our port		see what I mean). We also use a specific Redbrick server, Login (minerva) for our port
	forwarding (there are restrictions on tunnelling through our other machines). You can also add the ''-v'' option to specify 'verbose' mode and see the port being opened and closed for your tunnelled traffic.		forwarding (there are restrictions on tunnelling through our other machines). You can also add the ''-v'' option to specify 'verbose' mode and see the port being opened and closed for your tunnelled traffic.

← Older revision		Revision as of 14:00, 12 October 2008
Line 24:		Line 24:

	[[PuTTY]] has built-in support for port forwarding.		[[PuTTY]] has built-in support for port forwarding.
	* When you're connecting, after you've filled in the host name box (~~login.redbrick.dcu.ie or deathray.redbrick.dcu.ie or something~~ '''NOTE:''' If you wish to forward traffic through the DCU proxy the host name '''must''' be ~~deathray~~.redbrick.dcu.ie), click on Tunnels in the left-hand bar (second last item from the bottom).		* When you're connecting, after you've filled in the host name box ('''NOTE:''' If you wish to forward traffic through the DCU proxy the host name '''must''' be carbon.redbrick.dcu.ie), click on Tunnels in the left-hand bar (second last item from the bottom).
	* In the Port forwarding box, fill in the following values:		* In the Port forwarding box, fill in the following values:
	** Source port: (the port you want forwarded to the proxy - eg 1337)		** Source port: (the port you want forwarded to the proxy - eg 1337)
Line 42:		Line 42:

	If you read the neworder guide above you should have a good idea of how to build the SSH command for the forwarding, like so:		If you read the neworder guide above you should have a good idea of how to build the SSH command for the forwarding, like so:
	ssh -L 1337:proxy.dcu.ie:3128 ~~deathray~~.redbrick.dcu.ie		ssh -L 1337:proxy.dcu.ie:3128 carbon.redbrick.dcu.ie

	Where :		Where :
Line 49:		Line 49:
	* proxy.dcu.ie is the server you want to send your tunnelled traffic to.		* proxy.dcu.ie is the server you want to send your tunnelled traffic to.
	* 3128 is the port on that server you want to send your tunnelled traffic to.		* 3128 is the port on that server you want to send your tunnelled traffic to.
	* ~~login~~.redbrick.dcu.ie is the server you want to open the SSH connection to		* carbon.redbrick.dcu.ie is the server you want to open the SSH connection to


Line 55:		Line 55:

	For example, to tunnel local port 1337 to the SOCKS proxy on proxy3.dcu.ie through deathray:		For example, to tunnel local port 1337 to the SOCKS proxy on proxy3.dcu.ie through deathray:
	ssh -L 1337:proxy3.dcu.ie:1080 ~~deathray~~.redbrick.dcu.ie		ssh -L 1337:proxy3.dcu.ie:1080 carbon.redbrick.dcu.ie

	Here we see that we specify the proxy definitively, and use the port that we		Here we see that we specify the proxy definitively, and use the port that we
	would eventually negotiate (for those of you is res try running ~~Ethereal~~, you will		would eventually negotiate (for those of you is res try running Wireshark, you will
	see what I mean). We also use a specific Redbrick server, ~~Deathray~~ for our port		see what I mean). We also use a specific Redbrick server, Carbon for our port
	forwarding (there are restrictions on tunnelling through our other machines). You can also add the ''-v'' option to specify 'verbose' mode and see the port being opened and closed for your tunnelled traffic.		forwarding (there are restrictions on tunnelling through our other machines). You can also add the ''-v'' option to specify 'verbose' mode and see the port being opened and closed for your tunnelled traffic.