NAT ISP Workaround

Hello,

I'm trying to run a webserver from my home computer, but my ISP's
system is not cooperating. I have a wireless broadband system, which
is like Wi-Fi on steroids. Anyway, the ISP (BTInet) seems to have a
funny system to run this technology, here is the situation:

I'm using dyndns.org as a dynamic DNS package, as supposedly my IP
address is dynamic, though I have yet to see it change. Their system
shows my IP address as one thing (http://checkip.dyndns.org), as does
nearly any program I use to check it (call it IP1). However, when I
go into my router management panel, I see a different IP address
(IP2), but nowhere is the one reported by other programs. If I take
the IP2, I can use it on any computer on my network, and it directs to
my web site. Good. But if I try from elsewhere, no good. Also, IP1
will not work anywhere. So, I e-mailed the ISP to see if webhosting
was allowed, or they blocked ports, or what:

> Hello,
>
> I have a question as to whether server hosting is allowed from my
> house
> using the $35/month fixed wireless plan. From looking at the
> pricing
> sheet, I see that the $70 one does not allow server hosting, while
> the
> ones below (more expensive) do. However, the $35 one does not say
> anything about server hosting.
>
> If hosting is possible, I would use a dynamic DNS service to work
> around
> the dynamic IP address, along with attempting to keep the
> connection
> alive as long as possible. Would this be in violation of any
> license
> agreements/contracts?
>
> Also, maybe a question better asked of tech support, but related
> to the
> above:
> How is the no server hosting policy enforced? Is port 80 blocked?
>
> Thanks,
>
> Aaron

They reply:

> Hey Aaron,
> Thanks for the inquiry -- here's the basic story for the server hosting
> on the wireless:
>
> The lower end plans ($35 and $70) aren't really designed for server
> hosting, and the main reason we've done it that way is financial --
> server hosting usually creates higher than normal usage, so we try to
> limit it to the higher rate plans to help offset the cost of
> bandwidth.
>
> The $35 plan actually uses NAT'd addresses, which is the main limiting
> factor in being able to host a server. The $70 plan will only allow a
> max of 1 IP address, which is assigned to a router at your location and
> is used for authentication for your connectivity. I believe you'd need
> a second IP for the server, which is only available on the $99 plan.
> We don't block any ports, and it's not in violation of the agreement if
> you can find a way to make it work. You're welcome to try it, but we
> can't really provide any technical support for the server hosting.
>
> Hope that answers your questions, but feel free to email me or call me
> with any other questions. Thanks Aaron!
>
> Mitch

So, I'm guessing that their router is doing the same thing as mine,
i.e. translating from IP1 (which is their router address) to IP2, and
giving my router IP2. Other programs only see the IP of their router,
which is IP1. If so, it is a mirror of my home network, only I do not
have control of port forwarding, etc., as I have set up on my network.

I hope that was clear to someone; maybe there is a workaround? Is it
possible to call an IP within a network, like a nested IP or
something?

Thanks for any help; I can give more detail on request - ISP IP
numbers, etc.

Aaron