Fixed Lease DHCP Doesn't Work After Connecting Different Network

At my office the DHCP server leases me a specific IP address based on my MAC
address. I require this IP to use certain network services that are
restricted based on IP.

Everytime I use my laptop on another network and get leased an IP and then
return to the office I don't get my "fixed lease" IP based on MAC address.
The only way to get my assigned IP again is to assign myself a fixed IP and
then change back to DCHP. Somehow, these actions reset something so that I
get leased the correct IP again..

Why is this happening and who can I fix it without assigning myself a fixed
IP, applying and changing back to DHCP.

BTW - I'm not using wireless.

Thank!

On Nov 26, 2:49 am, John Shwon <JohnSh...@discussions.microsoft.com>
wrote:
> At my office the DHCP server leases me a specific IP address based on my MAC
> address. I require this IP to use certain network services that are
> restricted based on IP.
>
> Everytime I use my laptop on another network and get leased an IP and then
> return to the office I don't get my "fixed lease" IP based on MAC address.
> The only way to get my assigned IP again is to assign myself a fixed IP and
> then change back to DCHP. Somehow, these actions reset something so that I
> get leased the correct IP again..
>
> Why is this happening and who can I fix it without assigning myself a fixed
> IP, applying and changing back to DHCP.
>
> BTW - I'm not using wireless.
>
> Thank!

The DHCP service(s) do not release the IP address once you disvconnect
from the network. In order for the DHCP "client" (your's) to re-
request an DHCP based IP address on next boot-up, you need to issue
the following at the Command Prompt:

> ipconfig /release

John Shwon <JohnShwon@discussions.microsoft.com> wrote:
> At my office the DHCP server leases me a specific IP address based on
> my MAC address. I require this IP to use certain network services
> that are restricted based on IP.
>
> Everytime I use my laptop on another network and get leased an IP and
> then return to the office I don't get my "fixed lease" IP based on
> MAC address. The only way to get my assigned IP again is to assign
> myself a fixed IP and then change back to DCHP. Somehow, these
> actions reset something so that I get leased the correct IP again..
>
> Why is this happening and who can I fix it without assigning myself a
> fixed IP, applying and changing back to DHCP.
>
> BTW - I'm not using wireless.
>
> Thank!

This is normal but you're making life harder than you need to to fix it.
Either use ipconfig /release ....ipconfig /renew, or repair your connection
by right-clicking on it.

I tried ipconfig /release, and ipconfig /renew but I would not get the
correct IP assigned. I even tried "nuke-ing" my network stack using the
command on Scott Hanselmann's blog, but I still had the incorrect IP. The
only way that I found that works is speciying a fixed IP and then changing
back to DHCP.

Any idees?

"Lanwench [MVP - Exchange]" wrote:

> John Shwon <JohnShwon@discussions.microsoft.com> wrote:
> > At my office the DHCP server leases me a specific IP address based on
> > my MAC address. I require this IP to use certain network services
> > that are restricted based on IP.
> >
> > Everytime I use my laptop on another network and get leased an IP and
> > then return to the office I don't get my "fixed lease" IP based on
> > MAC address. The only way to get my assigned IP again is to assign
> > myself a fixed IP and then change back to DCHP. Somehow, these
> > actions reset something so that I get leased the correct IP again..
> >
> > Why is this happening and who can I fix it without assigning myself a
> > fixed IP, applying and changing back to DHCP.
> >
> > BTW - I'm not using wireless.
> >
> > Thank!
>
> This is normal but you're making life harder than you need to to fix it.
> Either use ipconfig /release ....ipconfig /renew, or repair your connection
> by right-clicking on it.
>
>
>

John Shwon <JohnShwon@discussions.microsoft.com> wrote:
> I tried ipconfig /release, and ipconfig /renew but I would not get the
> correct IP assigned.

What do you see in ipconfig /all after you try this? What's the DHCP server
address? Shouldn't be the one on the network you aren't connected to!

> I even tried "nuke-ing" my network stack using
> the command on Scott Hanselmann's blog, but I still had the incorrect
> IP. The only way that I found that works is speciying a fixed IP and
> then changing back to DHCP.
>
> Any idees?

What about repairing the connection, as I suggested?

One way around this would be to do an ipconfig /release *before* shutting
down on 'the other network" ....then when you boot up in your office you
should getthe correct IP.


>
> "Lanwench [MVP - Exchange]" wrote:
>
>> John Shwon <JohnShwon@discussions.microsoft.com> wrote:
>>> At my office the DHCP server leases me a specific IP address based
>>> on my MAC address. I require this IP to use certain network services
>>> that are restricted based on IP.
>>>
>>> Everytime I use my laptop on another network and get leased an IP
>>> and then return to the office I don't get my "fixed lease" IP based
>>> on MAC address. The only way to get my assigned IP again is to
>>> assign myself a fixed IP and then change back to DCHP. Somehow,
>>> these actions reset something so that I get leased the correct IP
>>> again..
>>>
>>> Why is this happening and who can I fix it without assigning myself
>>> a fixed IP, applying and changing back to DHCP.
>>>
>>> BTW - I'm not using wireless.
>>>
>>> Thank!
>>
>> This is normal but you're making life harder than you need to to fix
>> it. Either use ipconfig /release ....ipconfig /renew, or repair your
>> connection by right-clicking on it.