Configure 2nd DHCP in the Network .. HOW ?

[Guest_imported]

Hi,
I'm just trying my hands as a prospective Windows2K administrator.. We've a network of 350+ computers that are served IP addresses by a corporate DHCP server. All 350+ computers on the same subnet (255.255.240.0). All the 350+ computers have a primary DNS suffix of say, abc.com that is provided by the DHCP.

I'm trying to setup a mini network of 3 computers out of those 350+ computers.

I've installed a new Win2K adv. server on one of the computers (lets call this DC as MYDC1). I've made this win2k adv. server computer as a DC of a new domain say, xyz.com... so the dc becomes MYDC1.xyz.com (right ?)
This MYDC1 gets its IP info from the same corporate DHCP server.The primary DNS suffix shows xyz.com and the suffix search order has (xyz.com and abc.com)

I've added two computers into this domain.
COMP1 -> Windows NT 4.0 Workstation
COMP2 -> Windows 2000 Adv. Server (member server)

Things are working fine.. till now.

Now, I want to enable DHCP on MYDC1 and I want COMP1 and COMP2 to get its IP info from MYDC1 and not from the corporate DHCP.. Is it possible ?

I don't want to disturb the network of the 350+ computers..

Can anybody give me a hand with this.. ?

The first thing I've to do is.. give a static IP to MYDC1.. right ? If I put this MYDC1 in a new subnet.. say 255.255.255.0 .. would it be of any help .. ?

I'm a bit confused.. PLEASE .. SOMEBODY.. ANYBODY.. HELP ME !!

Anticipating a reply,

Regards,
Praveen.

 

[stuttle]

You have a class B subnet that allows 4094 hosts. Any subnet mask you assign will not help you if the entire 255.255.240.0 subnet is assigned as a scope in the corporate DHCP server. If you choose another network (this mask allows 14 within an entire class B), you will have to go through a router to get to the corporate network. This cannot be done arbitrarily, because the subnet may belong to another company. Get with your Network Admin and see if he has a range that has been excluded. If so, you can set this as your address pool and exclude the range provided by corporate. Authorize the server and the scope in Active Directory (your test domain), then your domain computers will pick up addresses from this server.

Mearly assigning another mask (e.g. 255.255.255.0) will cause ip conflicts and may disrupt corporate network operations. Make sure you really understand ip addressing before you do anything!

If you dual-home your member server and use a private addressing scheme for your test network, the server can be set up to route between the two networks (you must configure the routing and remote access service on that server and assign it as the gateway for clients).

Hope that helps!

Steve ----------------------------
Steven R. Tuttle
CBE, MCSE, BNCS, DCT, A+
stuttle@yahoo.com
----------------------------

 

[Guest_imported]

Hi.. Thanx Steven..

But.. I think I should clarify the network out here..

These 350+ computers are not part of any domain.. they are put in small-small workgroups.. My domain (xyz.com) is the only win2k domain in the whole network..

Also, I don't want the DHCP on MYDC1 to provide leases to any of the 350+ computers.. I want MYDC1 to provide leases to only COMP1 and COMP2 ..

But.. since COMP1 and COMP2 are part of xyz.com domain.. is it something like.. COMP1 & COMP2 will ask for IP addr only from MYDC1 and not from the corporate DHCP ?

Also, after COMP1 and COMP2 get their IP addresses from MYDC1, my test network should be able to talk to the remaining corporate network of 350+ computers.. Is that possible.. ?

And.. more over.. I'm trying these R&D activities during after-office hours.. so.. I cannot talk to the Network admin.. (in fact, I want to avoid talking to the Network Admin out here.. ;-P )

With all thse requirements and constraints.. can you provide me with step-by-step approach on how to go about this.. ?

Hope I'm making my requirements clear.. ?

anyways.. thanx for your help.. and expecting more clarifications..

thanx and regards,
Praveen.

 

[justcurious]

Windows machines broadcast their first DHCP request for an IP adddress. The first DHCP server to respond will provide the address. Half way through the lease life, each machine will then direct their next request to that DHCP server. If the lease expires, each Windows machine will then broadcast a new request. There is no way I know of that you can tell a machine to query a specific server.

Steve's routing suggestion is your best bet.

 

[brontosaurus]

Domain or not, it doesn't matter, listen to Steve...
DHCP is broadcast based, so the determination of who will provide the IP address and what that address will be is made BEFORE any domain related issues rise. That's why you can take your laptop from one location to another, plug it into a DHCP based network, and you're off and running. However, since it's broadcast based, it will not cross subnets unless you have a DHCP helper on your routers or a trunked VLAN setup. It's likely that your company is already reserving all of the available subnets, but maybe not. If you could get your machines onto a subnet that's not being used/reserved, then your clients would look to your server first for DHCP assignment. However, you don't want to talk with any admins, and understandably so, since you're trying to put a rogue DHCP server onto their network...

 

[CharlieJax]

You can do it, but you have to have a router sepearting you from the rest of the physcial network. What you can do is setup the server as a router and put it between your PCs and the rest of the network and allow it to route out to the rest of the company; but this will require two network cards, one for your PCs' side and one to talk to the rest of the company.

Then you can setup your DHCP to be bound to the network card that talks to your PCs.

Without a router or some sort of division between your DHCP server and any others in the company you cannot force PCs to get addresses from your machine.

You can, however stop other machines from getting addresses from your DHCP server by using reservations or other restrictions.

So here is what you need:

Your server with 2 network cards
One network port to the rest of the companies' network
One hub or switch connecting your 3 machines (the server and your other two PCs)
Once you setup the server to be a router and configure all of the traffic to go through it to reach the rest of the network you will be good to go. CJ
- Jr. Rocket Man