New IP Scheme with DHCP

I have a network of WinXP systems with Windows 2003 as my NOS. I am wanting
to totally change my IP addresses from 192.0.0.X to 172.16.X.X because our
network is about to grow. what is the best way to go about this? I added
another scope to my DHCP and then deactivated the 192.0.0.0 one and my PCs
will not pick up the new 172.16.0.0 IPs.

Any Ideas?

Thanks

"Matt Burks" <(E-Mail Removed)> ha scritto nel messaggio
news:%(E-Mail Removed)

> I have a network of WinXP systems with Windows 2003 as my NOS. I am
> wanting to totally change my IP addresses from 192.0.0.X to 172.16.X.X
> because our network is about to grow. what is the best way to go about
> this? I added another scope to my DHCP and then deactivated the 192.0.0.0
> one and my PCs will not pick up the new 172.16.0.0 IPs.
>
> Any Ideas?

Why not use 192.168.X.Y/255.255.0.0 ? This way, old IP addresses would
continue to be valid in the new network...
Anyway, to trigger a refres of the DHCP lease (normally retained for 8
days), you can use the command "ipconfig /renew" on client systems.
You can also set the scope option to release DHCP address when closing (it's
in the Microsoft-specific options), forcing the clients to obtain a new
lease upon each reboot.

Massimo

That is what I'm saying will not work. I do the ipconfig /renew and it will
not pick up the new address. It's as if it can't find the DHCP server or the
DHCP server isn't pushing the new scope out to be applied. The server has
the IPs 192.0.0.25 and 172.16.1.25 assigned to the same network card.


-Matt


"Massimo" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> "Matt Burks" <(E-Mail Removed)> ha scritto nel messaggio
> news:%(E-Mail Removed)
>
> > I have a network of WinXP systems with Windows 2003 as my NOS. I am
> > wanting to totally change my IP addresses from 192.0.0.X to 172.16.X.X
> > because our network is about to grow. what is the best way to go about
> > this? I added another scope to my DHCP and then deactivated the
192.0.0.0
> > one and my PCs will not pick up the new 172.16.0.0 IPs.
> >
> > Any Ideas?
>
> Why not use 192.168.X.Y/255.255.0.0 ? This way, old IP addresses would
> continue to be valid in the new network...
> Anyway, to trigger a refres of the DHCP lease (normally retained for 8
> days), you can use the command "ipconfig /renew" on client systems.
> You can also set the scope option to release DHCP address when closing
(it's
> in the Microsoft-specific options), forcing the clients to obtain a new
> lease upon each reboot.
>
> Massimo
>

"Matt Burks" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> That is what I'm saying will not work. I do the ipconfig /renew and it
will
> not pick up the new address. It's as if it can't find the DHCP server or
the
> DHCP server isn't pushing the new scope out to be applied. The server has
> the IPs 192.0.0.25 and 172.16.1.25 assigned to the same network card.

You have to wipe out all traces of the 192.x.x.x address set. You cannot
leave it on the DHCP machine, and you certainly don't want it to be the
"primary IP#" of the Nic. Remember that there can only one Primary IP# on a
NIC and all others are Secondary. You must remove all IP#s from the NIC and
then add the 172.16.1.25 address back to it so that it is the first (and
Primary) address.

Even on a non-DHCP machine the last thing you want to do is put two IP#s
from different subnets on the same interface.

DHCP makes its "decision" based on the NIC it received the request, since it
still has 192.0.0.25 on the Nic, that is the "logical interface" it receives
the request on from the 192.0.0.x client and expects to find a free IP# from
that subnet to hand out. Since it no longer has any such address it simply
sits there and does nothing. It will not use the 172 address becasue it did
not receive it on the 172 "logical interface". Remember the client expects
to get the same number everytime and will make its request along those
lines.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com

Ok, then how about this. I two NICs in this server, currently one is
disabled. Can I setup DHCP on that nic and give it the 172 ip address? I
don't want to take off the 129.0.0.25 IP since it is also my primary DNS
server.


-Matt



"Phillip Windell" <@.> wrote in message
news:%(E-Mail Removed)...
> "Matt Burks" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > That is what I'm saying will not work. I do the ipconfig /renew and it
> will
> > not pick up the new address. It's as if it can't find the DHCP server or
> the
> > DHCP server isn't pushing the new scope out to be applied. The server
has
> > the IPs 192.0.0.25 and 172.16.1.25 assigned to the same network card.
>
> You have to wipe out all traces of the 192.x.x.x address set. You cannot
> leave it on the DHCP machine, and you certainly don't want it to be the
> "primary IP#" of the Nic. Remember that there can only one Primary IP# on
a
> NIC and all others are Secondary. You must remove all IP#s from the NIC
and
> then add the 172.16.1.25 address back to it so that it is the first (and
> Primary) address.
>
> Even on a non-DHCP machine the last thing you want to do is put two IP#s
> from different subnets on the same interface.
>
> DHCP makes its "decision" based on the NIC it received the request, since
it
> still has 192.0.0.25 on the Nic, that is the "logical interface" it
receives
> the request on from the 192.0.0.x client and expects to find a free IP#
from
> that subnet to hand out. Since it no longer has any such address it simply
> sits there and does nothing. It will not use the 172 address becasue it
did
> not receive it on the 172 "logical interface". Remember the client expects
> to get the same number everytime and will make its request along those
> lines.
>
> --
>
> Phillip Windell [MCP, MVP, CCNA]
> www.wandtv.com
>
>

Where's the LAN Router? You can't have two subnets without a router. The
router is set to forward DHCP requests from the 172 to the 192 subnet. The
DHCP Server (which only needs a 192 nic) will "understand" what address the
user needs by the information provided to it from the router's message. The
DHCP Server simply needs a separate scope for each subnet that exists. You
might want to keep a scope for the 192 subnet even if nothing gets an
address from DHCP,.... just make the exclusion list to be the full range of
addresses on that subnet.

Yes, you could put two nics in the DHCP box for each subnet, but then you
have to determine if it is also going to be used as a router or not and then
also have to deal with any "duel-homed" related issue that come up. You're
better off using a router and keeping a nice neat & clean configuration that
is easier to troublshoot when it doesn't work.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com


"Matt Burks" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Ok, then how about this. I two NICs in this server, currently one is
> disabled. Can I setup DHCP on that nic and give it the 172 ip address? I
> don't want to take off the 129.0.0.25 IP since it is also my primary DNS
> server.
>
>
> -Matt
>
>
>
> "Phillip Windell" <@.> wrote in message
> news:%(E-Mail Removed)...
> > "Matt Burks" <(E-Mail Removed)> wrote in message
> > news:(E-Mail Removed)...
> > > That is what I'm saying will not work. I do the ipconfig /renew and it
> > will
> > > not pick up the new address. It's as if it can't find the DHCP server
or
> > the
> > > DHCP server isn't pushing the new scope out to be applied. The server
> has
> > > the IPs 192.0.0.25 and 172.16.1.25 assigned to the same network card.
> >
> > You have to wipe out all traces of the 192.x.x.x address set. You cannot
> > leave it on the DHCP machine, and you certainly don't want it to be the
> > "primary IP#" of the Nic. Remember that there can only one Primary IP#
on
> a
> > NIC and all others are Secondary. You must remove all IP#s from the NIC
> and
> > then add the 172.16.1.25 address back to it so that it is the first (and
> > Primary) address.
> >
> > Even on a non-DHCP machine the last thing you want to do is put two IP#s
> > from different subnets on the same interface.
> >
> > DHCP makes its "decision" based on the NIC it received the request,
since
> it
> > still has 192.0.0.25 on the Nic, that is the "logical interface" it
> receives
> > the request on from the 192.0.0.x client and expects to find a free IP#
> from
> > that subnet to hand out. Since it no longer has any such address it
simply
> > sits there and does nothing. It will not use the 172 address becasue it
> did
> > not receive it on the 172 "logical interface". Remember the client
expects
> > to get the same number everytime and will make its request along those
> > lines.
> >
> > --
> >
> > Phillip Windell [MCP, MVP, CCNA]
> > www.wandtv.com
> >
> >
>
>