Phoenix Network Forums

G'day,
I am a linux user. I don't profess to be a great linux user either and there are many things that I can always learn. I do know the basics and maybe a little beyond that.

My current situation is that I am trying to be able to access my linux machine from the internet. This is a problem because my ISP has all the internal addresses as NAT'ed private lan addresses and to make things even more exciting they are DHCP allocated.

There aren't a lot of solutions to this and I would be appreciative to anyone's suggestions as to how to work with this.

Cheers,
L8
(Leighton)

So you are actually behind an ISP firewall in an ISP-local network?

My connection to the internet is something like this:

Me
192.168.x.x
|
ISP Gateway
202.x.x.x
|
Internet


The ISP gateway, that my machine points to at home, is accessable from the internet, but I don't have any shell access to the ISP.
I asked for shell access, but they didn't seem too want to give me shell access. To me that would be the simpilest and cheapest solution to my problem.

The only other way I can think of doing it is creating a SSH tunnel to the outside world from my machine at home and then connecting through that tunnel.

Finding someone with a permanant connection who will allow that is another story and unfortunately is also not really optimal. At least it would allow me to SSH into my machine at home though.

Cheers,
L8

Do you have any other options as far as ISPs go? If they're giving you a raw deal, maybe you should drop them.

Unfortunately I am rather limited when it comes to ISP options.

I live on the Central Coast, NSW, Australia and the options for an internet connection are a little limited in the area that I am in. ADSL would probably be my prefered option, but the last time I checked, I didn't have a copper pair running back to an ADSL DSLAM. Consequently I couldn't get ADSL.

I can get:
Dial-up - who wants to go back to dial-up internet???
ISDN - but it is expensive and not a lot better than dial-up.
Wireless - this is what I currently have.

I have had Dial-up, ADSL, ISDN and now wireless access before. I have a general knowledge of how all these work and how to get my Linux box to interface to them.

I wasn't aware that the ISP didn't give you a "real" IP when I signed up. I have tried to push this, but maybe need to push it a little more. I don't have many other options though!

Other than that, I am rather happy with the wireless connection. It appears to have plenty of bandwidth for what I want.

L8

You have another option: VPN. This might solve your problem, if you coult bring your home machine to connect to the outside world. You could do this by a DynDNS account like this:

Create a DynDNS static hostname that points to 127.0.0.1. Let your machine connect periodically to that address, like every ten minutes or so. If you want to have access to your machine, change that hostname to point to the host you want to connect from. Then wait a few minutes, until your machine is connected to the remote host. After the VPN is established, you can connect to your home machine as if you where in a local subnet with it.

Ah ha!

Thanks! That is a great idea... I hadn't thought of that.

It would mean that I have to be able to configure the other end to allow the vpn to come through though. I was aiming at trying to avoid that as quite often the where I am accessing from is NAT'ed also. (Usually another ADSL connection or similar...)

I will see how I go with that option though.

Cheers,
L8

If you don't want that, you need some static host, which is always connected to your home host via VPN or something similar. Then you could use that host as a proxy service. Otherwise I don't see any other simple solution.

I thnk that you are right. I don't see any other simple option that is going to work for me.

It is not something that I utilise that often, but it is nice to be able to access my machine remotely.

At your suggestion, I am working on setting up a VPN similar to how you mentioned.

I am thinking of activating the VPN by phone. I have asterisk setup which should allow me to start a script running by calling into the box and going through an IVR system to activate it or something like that.

Thanks for the ideas and assistance!

Cheers,
L8

If you can phone your host, you don't need a VPN at all. Just make it connect somewhere outside or do your work over phone. =)

Yes, I guess using text-to-speech software, I could check my email and then voice recogntiion software could run other things on my box here...

I think that the VPN idea will suit my needs anyway.

That wasn't a joke. You can establish a network via a phone line.

As in a PPP or similar connection...?

I realise that you can do things such as PPP connections and console connections over the phone line.

The problem there, for me, is that I would have to have some way of dialing in from the other end to be able to connect in.

Am I missing something? Is there another way of doing it?

I had thought that, if there was some way of doing a data connection with my FWD number, it may work... I am not sure of any software or a way that would be able to do that?

Hmm... Getting complex there. I hope that all makes sense!

L8

You need a modem in both hosts. One host waits for incoming phone calls (the PPP server) and the other, which is the dialing one (the PPP client). After a connection between the two hosts is established, a network between them exists. Check out the PPP HOWTO.

Yes, I have a basic understanding of PPP etc...

I thought that you might have know of some other sneeky way to do something like Modem over VoIP without the modems.

I have managed to get the VPN part working anyway, just on a local test at home.