Fixed and Dynamic IP simultaneously

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jan.kindt

In XP pro, it's possible to assign multiple IP addresses to one network
interface. It seems to me that it is not possible to have both a
dynamic ip address and a fixed ip address on the same interface. Am I
right ? Does anybody knows the reason for this ?

I've got 2 networks : a very small (3 nodes) private network
(192.168.x.x range) and a large unknown network with DHCP enabled. I do
not want my private network to be exposed to the the large network. I
don't care too much if the private network uses DHCP or fixed IP
(altough fixed is the simplest). My idea was to use my computer (which
has only 1 network adapter) as a NAT device, but it seems not possible.
Any other suggestions on how I can keep a distinction between the
private and unknown network ?
 
If I recall aright, XP allows you to have an 'alternate' address for a
network adaptor - so you can have it use DHCP but if that's not available to
use a fixed IP - so if it's plugged into a DHCP network it will take an
address and if plugged into a non-DHCP network it will use the address you
give it. If you want to use it for NAT I would think you'd need two adaptors,
one configured for each network as an device cannot have two ip addresses at
the same time? Or have I misunderstood your question?
 
Well, it was my idea that a network adapter can have two ip addresses
at the same time. When using fixed ip addresses, it's possible to
assign several ip adresses to the same NIC.
I have found no way to do the same with DHCP enabled.
 
In XP pro, it's possible to assign multiple IP addresses to one network
interface. It seems to me that it is not possible to have both a
dynamic ip address and a fixed ip address on the same interface. Am I
right ? Does anybody knows the reason for this ?

I've got 2 networks : a very small (3 nodes) private network
(192.168.x.x range) and a large unknown network with DHCP enabled. I do
not want my private network to be exposed to the the large network. I
don't care too much if the private network uses DHCP or fixed IP
(altough fixed is the simplest). My idea was to use my computer (which
has only 1 network adapter) as a NAT device, but it seems not possible.
Any other suggestions on how I can keep a distinction between the
private and unknown network ?
Click to expand...

I don't think it's possible for a single network adapter to have a
dynamic IP address and a fixed IP address at the same time.

But it's certainly possible to use a Windows XP computer as a NAT
device, by adding a second network adapter (PCI or USB) and enabling
Internet Connection Sharing.

I'm curious: what is an "unknown" network? Why would you take the
risk of connecting your computer to it? Your computer will be exposed
to it, even if the rest of your private network isn't.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

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http://mvp.support.microsoft.com
 
I'm designing a networked device. The device consists of 2 electronic
boards and a single board computer. Those two boards and the computer
are communicating with each other over ehternet : this is my private
network.
The device itself can be placed into the clients network, wich I don't
know : hence the 'unknown' network from which I want to protect my
private network (especially the two electronic boards).

I'll move my thinking strategy over to using a dual ethernet port
single board computer.
 
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