service redirect ?

HI ,

I was wondering if there is an application that can accept connection
on a single port and then redirect to another port based on the TYPE of
service that is requested ?

EG: I connect to port 9000 with an ssh client - the "app" will then
redirect me to port 22.

maybe I want to pop my email - so I connect to port 9000 again and the
"app" will redirect me to port 110.

I was hoping that there is already something like this - before I
deceide to write one ...

many thanks
Tonino

On 2005-03-28, Tonino Greco <(E-Mail Removed)> wrote:
> I was wondering if there is an application that can accept connection
> on a single port and then redirect to another port based on the TYPE of
> service that is requested ?

This is what is usually called a proxy.
Now the question: WHY? Explain your problem, not your solution.

--
Linux: Because rebooting is for adding new hardware

hi,

the problem I have is that the firewall we have at work does not allow
pop3 or even http connections out and I want to be able to connect to
my home machine to pop my email as well as ssh on to my home box - as I
do work at home as well as work.

In essence I want to be able to use the ONE port they have open through
the firewall to connect to all the services on my home machine.

hmm - this sounds like a vpn ? or something like that ...?

On 2005-03-28, Tonino Greco <(E-Mail Removed)> wrote:
> the problem I have is that the firewall we have at work does not allow
> pop3 or even http connections out and I want to be able to connect to
> my home machine to pop my email as well as ssh on to my home box - as I
> do work at home as well as work.

Then talk to your sysadmins, if you have sound reasons they can just
poke an hole in the firewall for your IP. Remember that any attempt to
circumvent security policies can lead to reprimand or worse. If they
don't allow anything trought the firewall is for a good reason.

Davide

--
"Microsoft is the epitome of innovation and product quality."
-- This testimonial paid for by Microsoft.

In comp.os.linux.networking Tonino Greco <(E-Mail Removed)>:
> hi,

> the problem I have is that the firewall we have at work does not allow
> pop3 or even http connections out and I want to be able to connect to
> my home machine to pop my email as well as ssh on to my home box - as I
> do work at home as well as work.

> In essence I want to be able to use the ONE port they have open through
> the firewall to connect to all the services on my home machine.

man ssh
/-L

-L [bind_address:]port:host:hostport Specifies that the given
port on the local (client) host is to be forwarded to the
given host and port on the remote side. [..]

Just make sure you are allowed to do so, there are firewalls
designed to detect/reject even if this port is allowed but you
aren't using the service that is allowed to pass through.

--
Michael Heiming (X-PGP-Sig > GPG-Key ID: EDD27B94)
mail: echo (E-Mail Removed) | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 77: Typo in the code

Tonino Greco wrote:
> I was wondering if there is an application that can accept connection
> on a single port and then redirect to another port based on the TYPE
> of service that is requested ?

The port number identifies the "type of service". If you want to run
multiple services, each one requires a separate port.

--
Markku Kolkka
(E-Mail Removed)

Tonino Greco <(E-Mail Removed)> wrote:

> the problem I have is that the firewall we have at work does not allow
> pop3 or even http connections out and I want to be able to connect to
> my home machine to pop my email as well as ssh on to my home box - as I
> do work at home as well as work.
>
> In essence I want to be able to use the ONE port they have open through
> the firewall to connect to all the services on my home machine.

you could use SSH to forward the needed ports. Or you could even setup a
VPN connection to your home machine through this port. PPP-Over-SSH
should work to route a whole subnet or even the whole internet through
ohne port. Your machine at home just needs to have sshd and pppd
running and maybe do some NAT for you, if you want to access more
networks through this connection.


--
Regards,
Joern

Tonino Greco wrote:

> I was wondering if there is an application that can accept connection
> on a single port and then redirect to another port based on the TYPE of
> service that is requested ?
>

Many servers can be configured to listen on non-standard ports.

Tonino Greco wrote:

> hi,
>
> the problem I have is that the firewall we have at work does not allow
> pop3 or even http connections out and I want to be able to connect to
> my home machine to pop my email as well as ssh on to my home box - as I
> do work at home as well as work.
>
> In essence I want to be able to use the ONE port they have open through
> the firewall to connect to all the services on my home machine.
>
> hmm - this sounds like a vpn ? or something like that ...?

Find out what ports are available and then run a VPN, such as OpenVPN, which
can be configured to use any UDP (preferred) or TCP port.

BTW, what does your employer say about the resulting security issues or
accessing your stuff, on company time?

many thanks for all the info - and YES - exploiting an open port
through the firewall is NOT a great idea . I have therefore spoken to
the firewall admin regarding a VPN to home and he is ammenable to the
idea of using openvpn to connect my work machine and home machine -
BUT as long as my home machine is at home and not another company ...
He was worried about me circumventing the idea of a firewall and maybe
opening up a nice hole through their expensive firewall software

I think this will work. The idea of using openvpn and encryption is
very nice.

Many thanks for all the ideas ...

Tonino