How to configure for DYNAMIC IP Addresses
Jerome R. Westrick
jerry "at" westrick.com
Sat Jun 19 17:53:01 2004
Not enough info to suggest a solution...
Here the situation:
You can dynamic or static ip addresses.
This is (more or less) easy to diferentiate, if the machine is
autoconfigured, it dynamic, otherwise it is configure static
and you have to type in the address. (Note that some place give out
static ip addresses via the automaitc setting)...
This creates problems with people trying to connect to you since
they have no way of knowing your current address.
1) If the other party, has a static address, you can initiate the
connection from the "dynamic address" machine. This can be done
for both client and server.
2) Use a Dynamic DNS service (DDNS). This solution is better,
Here you add to your connection scripts a little program that
registers you current address dynamically, to a DNS service. Once
done, you can get your IP address from that service. There are free
service that do this for you. This is the only solution when both
parties have dynamic addresses.
But there is another problem you didn't ask,
You can have a local address, or a global address
Some addresses are not allowed to be transported via the internet.
This is done so that the addresses can be reused many times in diferent
locations. If this was not so the internet would have run out of
addresses a long time ago.
The most often used local address ranges are:
10.x.x.x, and 192.168.x.x
If your address is one of the above, nobody can connect to you,
since the address will not be transmitted via internet.
Here the solutions get complicated, you need to preconfigure the
NAT/Routesr to understand the situation and do address translatioin for
you. This is usually not do-able since this requires extensive support
from your provider, and most are not willing to do it.
So the solutions are:
1) if only one party has a local address,
always initiate the connection from that machine.
both parties have a local address, and you cannot have the
NAT/Routes configured for you),
or you need to initiate a connect to a local address
You need the help of a "Bouncer".
A "Bouncer" has a fixed global address, so both sides can always
connect to it. It receives the connections from both sides and
connects them. Unfortunatetly, all bytes sent go into and out agian
from the bouncer. And since the number of bytes you send to/from the
internet cost, the bouncer must recover this cost. GoToMyPc is a such
Hope this helped your understanding...
On Sat, 2004-06-19 at 13:37, Dean Bedford wrote:
> Hello from Praha,
> I have been reading through the RealVNC information and cannot locate
> any information on how to configure a machine that is using a dial-up
> connection and thus using a Dynamic IP address that changes all the
> Am I missing something or is a service such as GoToMyPC the direction to
> go in with dynamic IP's?
> All the best,
> Dean Bedford
> PLANet Systems Group
> 21707 Quaker Lane
> Middleburg, VA 20117
> Landline: 540.592.7183
> Mobile: 703.220.7327 (US)
> Mobile: 011 420 731 232 987 (Europe)
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