Diferent Gateways

Hi,

I have two ISP Connections and I want to have one group of PCs connecting
through gateway1 and other group through gateway2 and both groups get ip
trough DHCP.

I though create two scopes which one with one gateway configured, but how
can i say that groups of pcs use one scope and the other use the second
scope.

Thanks in advance.



Nuno Silva

might not be the best option, but DHCP user classes can be used, the the
class ID set via logon script or GPO script.

http://support.microsoft.com/kb/240247

Chris


"Nuno Silva" <(E-Mail Removed)> wrote in message
news:9A01E83C-C6FB-41B5-8592-(E-Mail Removed)...
> Hi,
>
> I have two ISP Connections and I want to have one group of PCs connecting
> through gateway1 and other group through gateway2 and both groups get ip
> trough DHCP.
>
> I though create two scopes which one with one gateway configured, but how
> can i say that groups of pcs use one scope and the other use the second
> scope.
>
> Thanks in advance.

You can really only get that to work if the machines are in different
Ethernet segments. Machines contact DHCP by using broadcasts. If the
machines are in different segments, they will get an IP from a scope which
matches the IP of the interface receiving the broadcast.

If the machines are in the same IP segment, this fails. There is no way
that the DHCP server can know which scope to use.

"Nuno Silva" <(E-Mail Removed)> wrote in message
news:9A01E83C-C6FB-41B5-8592-(E-Mail Removed)...
> Hi,
>
> I have two ISP Connections and I want to have one group of PCs connecting
> through gateway1 and other group through gateway2 and both groups get ip
> trough DHCP.
>
> I though create two scopes which one with one gateway configured, but how
> can i say that groups of pcs use one scope and the other use the second
> scope.
>
> Thanks in advance.

And if i make a scope from 192.168.1.1-50 and another from 192.168.1.51-100
whisch one will have a difrent gateway. How will be the beahvior? It will
use the first scope and then after computer 50 goes to the second scope?


"Bill Grant" <not.available@online> wrote in message
news:(E-Mail Removed)...
> You can really only get that to work if the machines are in different
> Ethernet segments. Machines contact DHCP by using broadcasts. If the
> machines are in different segments, they will get an IP from a scope which
> matches the IP of the interface receiving the broadcast.
>
> If the machines are in the same IP segment, this fails. There is no way
> that the DHCP server can know which scope to use.
>
> "Nuno Silva" <(E-Mail Removed)> wrote in message
> news:9A01E83C-C6FB-41B5-8592-(E-Mail Removed)...
>> Hi,
>>
>> I have two ISP Connections and I want to have one group of PCs connecting
>> through gateway1 and other group through gateway2 and both groups get ip
>> trough DHCP.
>>
>> I though create two scopes which one with one gateway configured, but how
>> can i say that groups of pcs use one scope and the other use the second
>> scope.
>>
>> Thanks in advance.
>
>

If the machines were on different segments you would not use IP addresses
in the same IP subnet. You would set up a scope for each segment with its
own IP subnet. Which scope the DHCP server used would depend on where the
request came from. Always remember that DHCP is a very simple system and it
relies on LAN broadcasts.

For example, if you want one segment to have IP addresses of 192.168.1.1
to 192.168.1.50 and a default gateway of 192.168.1.21 you set up your scope
to allow that. Any machine on that segment will get an IP of 192.168.1.x and
dg of 192.168.1.21 . If the DHCP server is on this segment and has an IP
address of 192.168.1.x everything works.

If you set up another scope of 192.168.2.1 and dg of 192.168.2.21 these
machines will not use that scope. That scope will only be used if a DHCP
request is received by a device with an IP address of 192.168.2.x . This
would only happen if the DHCP server had an interface with a 192.168.2.x
address (not a good idea) or if some device in the second segment could
receive the broadcast and send it through the network to the DHCP server.
This is called DHCP relay and is the way that a DHCP server knows which
scope to use. It uses a scope to match the IP address of the interface which
recieves the original broadcast request.


"Nuno Silva" <(E-Mail Removed)> wrote in message
news27EFA94-7838-4C62-90A2-(E-Mail Removed)...
> And if i make a scope from 192.168.1.1-50 and another from
> 192.168.1.51-100 whisch one will have a difrent gateway. How will be the
> beahvior? It will use the first scope and then after computer 50 goes to
> the second scope?
>
>
> "Bill Grant" <not.available@online> wrote in message
> news:(E-Mail Removed)...
>> You can really only get that to work if the machines are in different
>> Ethernet segments. Machines contact DHCP by using broadcasts. If the
>> machines are in different segments, they will get an IP from a scope
>> which matches the IP of the interface receiving the broadcast.
>>
>> If the machines are in the same IP segment, this fails. There is no
>> way that the DHCP server can know which scope to use.
>>
>> "Nuno Silva" <(E-Mail Removed)> wrote in message
>> news:9A01E83C-C6FB-41B5-8592-(E-Mail Removed)...
>>> Hi,
>>>
>>> I have two ISP Connections and I want to have one group of PCs
>>> connecting through gateway1 and other group through gateway2 and both
>>> groups get ip trough DHCP.
>>>
>>> I though create two scopes which one with one gateway configured, but
>>> how can i say that groups of pcs use one scope and the other use the
>>> second scope.
>>>
>>> Thanks in advance.
>>
>>

Thanks Bill once again

"Bill Grant" <not.available@online> wrote in message
news:(E-Mail Removed)...
> If the machines were on different segments you would not use IP
> addresses in the same IP subnet. You would set up a scope for each segment
> with its own IP subnet. Which scope the DHCP server used would depend on
> where the request came from. Always remember that DHCP is a very simple
> system and it relies on LAN broadcasts.
>
> For example, if you want one segment to have IP addresses of
> 192.168.1.1 to 192.168.1.50 and a default gateway of 192.168.1.21 you set
> up your scope to allow that. Any machine on that segment will get an IP of
> 192.168.1.x and dg of 192.168.1.21 . If the DHCP server is on this
> segment and has an IP address of 192.168.1.x everything works.
>
> If you set up another scope of 192.168.2.1 and dg of 192.168.2.21
> these machines will not use that scope. That scope will only be used if a
> DHCP request is received by a device with an IP address of 192.168.2.x .
> This would only happen if the DHCP server had an interface with a
> 192.168.2.x address (not a good idea) or if some device in the second
> segment could receive the broadcast and send it through the network to the
> DHCP server. This is called DHCP relay and is the way that a DHCP server
> knows which scope to use. It uses a scope to match the IP address of the
> interface which recieves the original broadcast request.
>
>
> "Nuno Silva" <(E-Mail Removed)> wrote in message
> news27EFA94-7838-4C62-90A2-(E-Mail Removed)...
>> And if i make a scope from 192.168.1.1-50 and another from
>> 192.168.1.51-100 whisch one will have a difrent gateway. How will be the
>> beahvior? It will use the first scope and then after computer 50 goes to
>> the second scope?
>>
>>
>> "Bill Grant" <not.available@online> wrote in message
>> news:(E-Mail Removed)...
>>> You can really only get that to work if the machines are in different
>>> Ethernet segments. Machines contact DHCP by using broadcasts. If the
>>> machines are in different segments, they will get an IP from a scope
>>> which matches the IP of the interface receiving the broadcast.
>>>
>>> If the machines are in the same IP segment, this fails. There is no
>>> way that the DHCP server can know which scope to use.
>>>
>>> "Nuno Silva" <(E-Mail Removed)> wrote in message
>>> news:9A01E83C-C6FB-41B5-8592-(E-Mail Removed)...
>>>> Hi,
>>>>
>>>> I have two ISP Connections and I want to have one group of PCs
>>>> connecting through gateway1 and other group through gateway2 and both
>>>> groups get ip trough DHCP.
>>>>
>>>> I though create two scopes which one with one gateway configured, but
>>>> how can i say that groups of pcs use one scope and the other use the
>>>> second scope.
>>>>
>>>> Thanks in advance.
>>>
>>>
>
>