• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 863
  • Last Modified:

Possible to run two DHCP scopes?

I was wondering if I could get my win2k DHCP server to have two separate scopes.
One would be for 192.168.1.1-192.168.1.12

The other would be for 192.168.2.1.-192.168.2.12

I have my LAN segmented (2 cisco routers)

Would this work or am I crazy?  
0
dissolved
Asked:
dissolved
  • 9
  • 3
  • 3
  • +1
1 Solution
 
dlwyatt82Commented:
That is a perfectly normal configuration. You just need to make sure that your router is configured to forward BOOTP / DHCP packets to the IP address of your DHCP server.
0
 
dlwyatt82Commented:
For further clarification - DHCP traffic is broadcast, and does not pass beyond the boundary of a physical segment (router) by design. Assuming your DHCP server is on the 192.168.1.0 segment, clients on the 192.168.2.0 segment can't receive addresses unless your router is configured to forward any BOOTP / DHCP packets from that subnet to the IP address of the DHCP server.

The router, before forwarding packets on to the DHCP server, identifies its IP address in a "gateway" field, so the DHCP server knows which IP subnet the request is coming from. It checks to see if you have a scope defined that matches the appropriate IP range, and if you do have a properly activated scope, picks an address from that pool.
0
 
dissolvedAuthor Commented:
Thanks man.
2 more questions.

1. what ports need to be forwarded on my routers?

2. Will the clients on the 192.168.2.0 network, automatically receive a 192.168.2. address from the DNS server?
Thanks
0
Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

 
dgroscostCommented:
Are you going to use a DHCP Relay Agent (Win2003) for your other location?  
0
 
dissolvedAuthor Commented:
I didnt plan to. But after doing some research, it looks like I will need a DHCP relay agent because I have a segmented lan (192.168.1.0 and 192.168.2.0).
Am I correct?
0
 
dlwyatt82Commented:
1. You don't need to know the specific port numbers, there should be an option explicitly named "BOOTP forwarding" or "DHCP forwarding". It is a standard option on current routers. I don't remember the UDP port numbers off the top of my head, but you can find them with a quick google search if you're curious :)

2. As long as you have already configured and activated a scope for the 192.168.2. subnet on your DHCP server, then yes. Any client who has a DHCP request forwarded from the 192.168.2. subnet will receive an IP address from that scope.
0
 
dlwyatt82Commented:
dissolved - if your router supports BOOTP forwarding, then you don't need to use a Windows server with the DHCP Relay Agent. I honestly don't know why Microsoft highlights this option so frequently, which virtually all current routers on the market support forwarding of BOOTP / DHCP packets.
0
 
dlwyatt82Commented:
For more information regarding DHCP and how the relay agents (whether on a router or a Windows machine) work, check out this link: http://www.microsoft.com/resources/documentation/WindowsServ/2003/standard/proddocs/en-us/sag_DHCP_und_RelayAgentNode.asp

This is from the 2003 documentation, but the information is accurate for 2000 as well.
0
 
dissolvedAuthor Commented:
Thanks guys. Now I have to find out how to activate DHCP forwarding on my cisco router (cisco newb here)

Thanks again
0
 
magus123Commented:
if your using windows 2000 server . all answers above are correct .
you should also consider using the superscope feature in dhcp .
0
 
dlwyatt82Commented:
Magus, configuring superscopes in this situation is not really appropriate. They are used to group together multiple scopes into a single logical scope when several logical IP network addresses are being used on the same physical subnet. In dissolved's network, there are two physical subnets, each with a single logical IP subnet.

If he were to create 2 superscopes, one each containing only one scope, nothing interesting would happen. It wouldn't break anything, but nothing would be gained, either.
If he created a single superscope containing both scopes, the system would begin handing out the wrong addresses to random clients on one or both subnets.
0
 
dlwyatt82Commented:
Note - my last comment refers to the way DHCP superscopes work in Windows Server 2003. I don't remember for sure if this was the way it worked in Windows 2000 DHCP.
0
 
dlwyatt82Commented:
Just double checked - the implementation of superscopes is the same for Windows 2000. See http://www.microsoft.com/resources/documentation/windows/2000/server/reskit/en-us/tcpip/part2/tcpch04.mspx
0
 
magus123Commented:
dlwyatt82 ,
i am goin to have to look more into that , my understanding of scopes must be a little off , the basics
are their , but the way they are applied ill hve to see. thanks.
0
 
magus123Commented:
after some resarch your conslusion

1. scope = creation of  1 scope/range  per subnet.
2. superscope = multiple ranges for only 1 subnet.

is this correct  scopes can give you ranges but are only applicable to 1 subnet.
thanks for any info , i appreciate your help , as i studying this stuff right now.
0
 
dlwyatt82Commented:
That's essentialy correct, magus. It helps to specify "physical" or "logical" in the explanation, as the word "subnet" is used to refer to both:

A Scope is a range of DHCP addresses in one Logical subnet.
A superscope is a collection of Scopes (Logical subnets) which all apply to one Physical subnet.

0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

  • 9
  • 3
  • 3
  • +1
Tackle projects and never again get stuck behind a technical roadblock.
Join Now