Re: How important is static IP?

["Julian Samphire" <jules@xxxxxxx>]

>
> It seems a few of us are trying to decide which ADLS ISP to go
with
> at the moment, so I'd like to know just how important those who've
> already taken the plunge feel it is to have static IP?
>
> Which HA toys might need static now or in the near future?
>
> I presume if I want to run a mail server I need static for my DNS
MX
> record to point to. Is this correct, or could you get away with
> something like dyndns? My guess is that dyndns would sometimes be
out
> of date and mail would get bounced.
>
> All help and advice greatly appreciated by me and many others I'm
> sure.
>
> SC

Its all a matter of whether or not you can live with port redirection?

Example: Lets say you have three web service devices/machine

inter/intranet
camera server
homeseer

You might want something like

http://intranet.mydomain.com/
http://camserv.mydomain.com/
http://homeseer.mydomain.com/

or could you live with

http://home.mydomain.com/
http://home.mydomain.com:81/
http://home.mydomain.com:82/

However, you could get a bit more funky with the single ip and put a
web
server on home.mydomain.com which used host header redirection and
redirects
you to another port ie.

You browse http://intranet.mydomain.com/
which resolves to 1.2.3.4 (your
external ip address). Your webserver then sees that you typed in
intranet.mydomain.com and redirects your browser to
http://home.mydomain.com:81/ but
you will probably have to set up internal
DNS resolution (or host files) to make sure you can resolve all this
when
you browsing internally on your network.

Anyway, I'm getting side tracked here.

If you get 5+1 ip addresses from your dsl provider you actually get 8
ip
addresses but only 6 of them are usable. ie. You are assigned the
following
range, and this is how the ip's are broken down:

1.2.3.0 - network address
1.2.3.1 - free
1.2.3.2 - free
1.2.3.3 - free
1.2.3.4 - free
1.2.3.5 - free
1.2.3.6 - usually the router address
1.2.3.7 - broadcast address

However, this is nice but you'll need to find a dsl modem/router that
can
cope with routed IP addresses and as well as NAT or you'll have to give
all
the machines in your building one of the five ip addresses. The problem
with
this is you can only have 5 machines on you intranet before you start
running into problems. You also have the problem of exposing all the
machines (and all their ports) to live internet traffic (hack central
possible if you're not careful).

So, what you might want to consider if having a firewall which supports
NAT
sitting behind the modem/router. ie.

Internet--Modem/Router--Firewall--Switch/Hub--Computers

This will allow your firewall to handle all the ip traffic for your
range
while mapping external ip addresses to your internal range ie.

1.2.3.1 -> 192.168.100.1 (intranet machine)
1.2.3.2 -> 192.168.100.2 (camera server)
1.2.3.3 -> 192.168.100.3 (homeseer)
1.2.3.4 (pcanywhere ports only) -> 192.168.100.4 (your workstation so
you
can remote admin it)
1.2.3.4 (ftp) -> 192.168.100.1 (intranet machine running ftp server)
1.2.3.5 - free
etc
etc

Basically the options are pretty much unlimited (unless you want more
than
five separate web service devices, but you can dabble with host header
redirection if its just web sites).

I think I have covered most things, if anyone wants any more info on
this,
email me off group, or post it to group if you feel it worthwhile :)

Regards,

Jules




For more information: http://www.automatedhome.co.uk
Post message: ukha_d@xxxxxxx 
Subscribe:  ukha_d-subscribe@xxxxxxx 
Unsubscribe:  ukha_d-unsubscribe@xxxxxxx 
List owner:  ukha_d-owner@xxxxxxx

Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.