How to Assign IP Addresses to networked devices based upon MAC

Reasoning: We have IP Phone Systems using up the IP Address Space of the
existing network.
Microsoft DHCP Service doesn't seem to allow an option to specify a portion
of a MAC to be used to specify what subnet the device should be assigned to.

Example: If MAC matches 006089* then assign IP from subnet 10.10.100.0




Mr. Smith

I'm just guessing but surely you would want an ip address to be unique so
assigning a single address to a widlcard MAC address could be bad. MS DHCP
service lets you reserve an IP address for a full MAC address, why would you
want something different.. Do you swap out equipment that often?

"Mr. Smith" wrote:

> Reasoning: We have IP Phone Systems using up the IP Address Space of the
> existing network.
> Microsoft DHCP Service doesn't seem to allow an option to specify a portion
> of a MAC to be used to specify what subnet the device should be assigned to.
>
> Example: If MAC matches 006089* then assign IP from subnet 10.10.100.0
>
>
>

I'm unsure that Microsoft DHCP will provide you with an easy answer. I
am not familiar with your infrastructure, but putting phones on a
separate VLAN and assign devices on that VLAN a certain range of
addresses could provide a solution.

Mr. Smith wrote:
> Reasoning: We have IP Phone Systems using up the IP Address Space of the
> existing network.
> Microsoft DHCP Service doesn't seem to allow an option to specify a portion
> of a MAC to be used to specify what subnet the device should be assigned to.
>
> Example: If MAC matches 006089* then assign IP from subnet 10.10.100.0
>
>

I may of missed read your question, I'm not sure how many IP phones we are
talking about but you may be able to create a user class ID or vendor class
ID see http://support.microsoft.com/kb/240247/EN-US/ this may not be suitable
for your situation but it may be worth looking at.

"Paul Mckenna" wrote:

> I'm just guessing but surely you would want an ip address to be unique so
> assigning a single address to a widlcard MAC address could be bad. MS DHCP
> service lets you reserve an IP address for a full MAC address, why would you
> want something different.. Do you swap out equipment that often?
>
> "Mr. Smith" wrote:
>
> > Reasoning: We have IP Phone Systems using up the IP Address Space of the
> > existing network.
> > Microsoft DHCP Service doesn't seem to allow an option to specify a portion
> > of a MAC to be used to specify what subnet the device should be assigned to.
> >
> > Example: If MAC matches 006089* then assign IP from subnet 10.10.100.0
> >
> >
> >

I was attempting on not using VLAN solution...
All the VOIP Phones begain with the same vendor class MAC Address which
begain with 006089 so with that I wanted to just poing them to another
subnet .

"Richard Giagnacovo" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> I'm unsure that Microsoft DHCP will provide you with an easy answer. I am
> not familiar with your infrastructure, but putting phones on a separate
> VLAN and assign devices on that VLAN a certain range of addresses could
> provide a solution.
>
> Mr. Smith wrote:
>> Reasoning: We have IP Phone Systems using up the IP Address Space of the
>> existing network.
>> Microsoft DHCP Service doesn't seem to allow an option to specify a
>> portion of a MAC to be used to specify what subnet the device should be
>> assigned to.
>>
>> Example: If MAC matches 006089* then assign IP from subnet 10.10.100.0

What happens when you add phones next year? Will the vendor have the same
first 6 digits next year? Maybe not.

If you want them on a separate subnet I think the only way you can do this
is to setup a second scope on your dhcp server and set the number of IP
addresses in the range to the number of IP phones you have. Then you need
to fill the scope with all the reservations for each phone. Each time you
add an IP phone you will increase the available IPs by one and add the
reservation. This way the computers will not be able to draw from that
scope.

What you will need to do is to create a second scope
"Mr. Smith" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
>I was attempting on not using VLAN solution...
> All the VOIP Phones begain with the same vendor class MAC Address which
> begain with 006089 so with that I wanted to just poing them to another
> subnet .
>
> "Richard Giagnacovo" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> I'm unsure that Microsoft DHCP will provide you with an easy answer. I
>> am not familiar with your infrastructure, but putting phones on a
>> separate VLAN and assign devices on that VLAN a certain range of
>> addresses could provide a solution.
>>
>> Mr. Smith wrote:
>>> Reasoning: We have IP Phone Systems using up the IP Address Space of
>>> the existing network.
>>> Microsoft DHCP Service doesn't seem to allow an option to specify a
>>> portion of a MAC to be used to specify what subnet the device should be
>>> assigned to.
>>>
>>> Example: If MAC matches 006089* then assign IP from subnet 10.10.100.0
>
>