multiple DHCP in one network

Hi all,
I have mutiple DHCP servers in one network, each has a scope with a
different NetID. I want to ensure that computers with specific
physical location receive an IP from the required DHCP, how can I do
it??
E.g.:
computers in the second floor should have all an IP with NetID
192.168.2.0 (from DHCP2)
computers from the third floor should all have an IP with the NetID
192.168.3.0 (from DHCP3)
etc....

Thanx,
sony

On 14 Aug 2004 03:24:24 -0700, sony wrote:

> Hi all,
> I have mutiple DHCP servers in one network, each has a scope with a
> different NetID. I want to ensure that computers with specific
> physical location receive an IP from the required DHCP, how can I do
> it??
> E.g.:
> computers in the second floor should have all an IP with NetID
> 192.168.2.0 (from DHCP2)
> computers from the third floor should all have an IP with the NetID
> 192.168.3.0 (from DHCP3)
> etc....
>
> Thanx,
> sony

Unfortunately it is not so simple to do.
One solution is to use DHCP classes to arrange your clients in to different
subnets, but you will end up setting a DHCP class on each client manually,
so it is not a real solution.

In theory, there is no way to tell which DHCP server will assign an IP
address to any of your clients, because there is no rule -- clients chose
the DHCP server that answers to their request the first.

Best regards,

--
Zoltan Fekete <(E-Mail Removed)>
Microsoft Certified Professional

YU Spin d.o.o. Novi Sad - http://www.yuspin.co.yu
NetSee Network Utility - http://yuspin.metrohive.net/netsee

Zoltan Fekete wrote:


>
> Unfortunately it is not so simple to do.
> One solution is to use DHCP classes to arrange your clients in to
> different subnets, but you will end up setting a DHCP class on each
> client manually, so it is not a real solution.
>
> In theory, there is no way to tell which DHCP server will assign an IP
> address to any of your clients, because there is no rule -- clients
> chose the DHCP server that answers to their request the first.

Split each floor up with routers, don't forward the DHCP/bootp requests
across routers, and have a DHCP server on each floor.

Not very elegant, but it should work, and its slightly better than visiting
each client to set DHCP class.

The question the original poster should be asking themselves is whether or
not the thing they are trying to achieve here is worth all the hassle that
either of our ideas is going to cause them. Unless their setup already takes
them close to one of our answers for an unrelated reason already, then I
would have to say its not worth it.

Rob.
MS MVP

Agree is not simple to do, and probably not worth the hassle. Possible to
do this with VLANs and subnetting by floors. The OP can setup DHCP such
that the same floors of each building receive IP address configuration from
the same DHCP server. For example, floors 1-4 of every building receive IP
address configuration from DHCP01, floors 5-8 of every building receive IP
address configuration from DHCP02, floors 9-12 of every building receive IP
address configuration from DHCP03. In this situation, he would need to make
every floor a subnet, and configure a router on every floor/subnet to
forward BOOTP messages (The router must be RFC 1542 compliant to do this and
almost all new routers are) AND the routers MUST be further configured to
pass IP info only from a specific DHCP server to the requesting IP address
depending on it's floor (subnet). Then, at the DHCP servers themselves, he
would configure each with 33% of the available IP's (with 3 DHCP servers).
If he had four DHCP servers, he would configure each with 25% of the
available IPs, etc.... DHCP scope options for every floor/subnet such that
it's default gateway will only point to a VLAN that their respective DHCP
server is on. All DHCP options should be set at the scope level in this
design. Each scope (IP pool) can have up to about ~ 250 dynamic IP
addresses, leaving 4 available for the router and any other static hosts on
the subnet. He can use the default lease time and of course ensure no
devices are hard-coded with IPs in the dynamic range. Again, this DHCP
design takes an enormous amount of administrative work up front. And it is
not the classically recommended 80/20 DHCP server design. But once
everything is configured, the OP will achieve his design goals.

--
Todd J Heron, MCSE
Windows 2003/2000/NT


"Robert Moir" <(E-Mail Removed)> wrote in message
news:#(E-Mail Removed)...
> Zoltan Fekete wrote:
>
>
> >
> > Unfortunately it is not so simple to do.
> > One solution is to use DHCP classes to arrange your clients in to
> > different subnets, but you will end up setting a DHCP class on each
> > client manually, so it is not a real solution.
> >
> > In theory, there is no way to tell which DHCP server will assign an IP
> > address to any of your clients, because there is no rule -- clients
> > chose the DHCP server that answers to their request the first.
>
> Split each floor up with routers, don't forward the DHCP/bootp requests
> across routers, and have a DHCP server on each floor.
>
> Not very elegant, but it should work, and its slightly better than
visiting
> each client to set DHCP class.
>
> The question the original poster should be asking themselves is whether or
> not the thing they are trying to achieve here is worth all the hassle that
> either of our ideas is going to cause them. Unless their setup already
takes
> them close to one of our answers for an unrelated reason already, then I
> would have to say its not worth it.
>
> Rob.
> MS MVP
>
>

In last post, (around the middle) meant to say the DHCP scope options are
configured for every floor/subnet and the IP device points it's default
gateway to the floor router.

--
Todd J Heron, MCSE
Windows 2003/2000/NT


"Todd J Heron" <(E-Mail Removed)> wrote in message
news:eUPq#(E-Mail Removed)...
> Agree is not simple to do, and probably not worth the hassle. Possible to
> do this with VLANs and subnetting by floors. The OP can setup DHCP such
> that the same floors of each building receive IP address configuration
from
> the same DHCP server. For example, floors 1-4 of every building receive
IP
> address configuration from DHCP01, floors 5-8 of every building receive IP
> address configuration from DHCP02, floors 9-12 of every building receive
IP
> address configuration from DHCP03. In this situation, he would need to
make
> every floor a subnet, and configure a router on every floor/subnet to
> forward BOOTP messages (The router must be RFC 1542 compliant to do this
and
> almost all new routers are) AND the routers MUST be further configured to
> pass IP info only from a specific DHCP server to the requesting IP address
> depending on it's floor (subnet). Then, at the DHCP servers themselves,
he
> would configure each with 33% of the available IP's (with 3 DHCP servers).
> If he had four DHCP servers, he would configure each with 25% of the
> available IPs, etc.... DHCP scope options for every floor/subnet such
that
> it's default gateway will only point to a VLAN that their respective DHCP
> server is on. All DHCP options should be set at the scope level in this
> design. Each scope (IP pool) can have up to about ~ 250 dynamic IP
> addresses, leaving 4 available for the router and any other static hosts
on
> the subnet. He can use the default lease time and of course ensure no
> devices are hard-coded with IPs in the dynamic range. Again, this DHCP
> design takes an enormous amount of administrative work up front. And it
is
> not the classically recommended 80/20 DHCP server design. But once
> everything is configured, the OP will achieve his design goals.
>
> --
> Todd J Heron, MCSE
> Windows 2003/2000/NT
>
>
> "Robert Moir" <(E-Mail Removed)> wrote in message
> news:#(E-Mail Removed)...
> > Zoltan Fekete wrote:
> >
> >
> > >
> > > Unfortunately it is not so simple to do.
> > > One solution is to use DHCP classes to arrange your clients in to
> > > different subnets, but you will end up setting a DHCP class on each
> > > client manually, so it is not a real solution.
> > >
> > > In theory, there is no way to tell which DHCP server will assign an IP
> > > address to any of your clients, because there is no rule -- clients
> > > chose the DHCP server that answers to their request the first.
> >
> > Split each floor up with routers, don't forward the DHCP/bootp requests
> > across routers, and have a DHCP server on each floor.
> >
> > Not very elegant, but it should work, and its slightly better than
> visiting
> > each client to set DHCP class.
> >
> > The question the original poster should be asking themselves is whether
or
> > not the thing they are trying to achieve here is worth all the hassle
that
> > either of our ideas is going to cause them. Unless their setup already
> takes
> > them close to one of our answers for an unrelated reason already, then I
> > would have to say its not worth it.
> >
> > Rob.
> > MS MVP
> >
> >
>
>

Hi all,
I would like to thank all people who posted a reply. I already thought
of the "classes" solution, but I thought there may be another method
of achieving this. The method of using multiple routers is too much
for our network. Assigning a class to each client is ok in our
organization because it has only 30 clients, so it is managable to set
on each and assign a class to each one of them.

May be somebody else has another idea

Regards

You need to tell us more about your infrastructure and what you hope to
achieve by assigning different scopes to each floor. If all floors are
connected through a single switched network, then using different subnets
without VLans or routing will result in computers on different floors being
unable to communicate with eachother. Perhaps this is your goal? If each
floor is a separte physical network, then you can use your DHCP servers as
routers by installing an extra NIC and running an ethernet cable to the
appropriate floor.

Doug Sherman
MCSE Win2k/NT4.0, MCSA, MCP+I, MVP

"sony" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Hi all,
> I have mutiple DHCP servers in one network, each has a scope with a
> different NetID. I want to ensure that computers with specific
> physical location receive an IP from the required DHCP, how can I do
> it??
> E.g.:
> computers in the second floor should have all an IP with NetID
> 192.168.2.0 (from DHCP2)
> computers from the third floor should all have an IP with the NetID
> 192.168.3.0 (from DHCP3)
> etc....
>
> Thanx,
> sony

You already said that the Scope from each DHCP was a different Net ID,
....that means that you already have subnets,..that means you already have at
least one router. Therefore you just simply run *one* nic in each DHCP
Server and locate it in the subnet that is belongs in. All done,..no
problem.

With a small 30 client network, it shouldn't be any more complicated than
that. Now if you really only have one subnet, then leave it that way,...30
clients doesn't amount to squat and will run fine on a single subnet. You
would only need one DHCP, but could run two for dedundency by configuring
them identically with identical Scopes and the simply use Exclusions in the
scopes so that each server gives out 1/2 of the available addresses each.

--

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


"sony" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Hi all,
> I would like to thank all people who posted a reply. I already thought
> of the "classes" solution, but I thought there may be another method
> of achieving this. The method of using multiple routers is too much
> for our network. Assigning a class to each client is ok in our
> organization because it has only 30 clients, so it is managable to set
> on each and assign a class to each one of them.
>
> May be somebody else has another idea
>
> Regards

Does "ZZZT" ring a bell? (If I spelled it right)

--

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



"Todd J Heron" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...

Yep! Surprised to see ya in here, surprised even more so to still see you
still posting in microsoft.public.proxy (I just went in there to check)!

--
Todd J Heron, MCSE
Windows 2003/2000/NT


"Phillip Windell" <@.> wrote in message
news:#(E-Mail Removed)...
> Does "ZZZT" ring a bell? (If I spelled it right)
>
> --
>
> Phillip Windell [MCP, MVP, CCNA]
> www.wandtv.com
>
>
>
> "Todd J Heron" <(E-Mail Removed)> wrote in message
> news:%(E-Mail Removed)...
>
>