On December 28, 2004, in SBS Installation, by


As it’s stated here on a web site:

  1. What is DHCP?

    DHCP stands for “Dynamic Host Configuration Protocol”.

  2. What is DHCP’s purpose?

    DHCP’s purpose is to enable individual computers on an IP network to extract their configurations from a server (the ‘DHCP server’) or servers, in particular, servers that have no exact information about the individual computers until they request the information. The overall purpose of this is to reduce the work necessary to administer a large IP network. The most significant piece of information distributed in this manner is the IP address.

I have found that things just work “better” if you let the SBS server be the DHCP “hander-outer”, that is, it NOT your Linksys/firewall/router is the one handing out the IP addresses.  Again, if you are migrating from peer to peer this is a bit unusual as you’ve been used to having a router that does this function.  But IMHO [in my humble opinion] the SBS network works the best [connectcomputer works better, wizards run nicer] if the SBS box is in charge of DHCP and DNS.  If you ensure that the router has it’s DHCP function disabled BEFORE you begin to set up the system, the SBS box will automagically set up the DHCP/DNS functions.  Go into the webbased interface and adjust the router to have DHCP disabled and then set up your SBS box.  It will no longer see another DHCP server and shut it’s own down. 

If the SBS box sees any other DHCP server [like your router] on it’s same subnet it will shut it’s own DHCP server down.  Don’t forget to run the VPN wizard as I’ve seen my server want to turn RRAS into a DHCP server without running that wizard.


5 Responses to Who’s YOUR DHCP

  1. Tony Su says:

    Hello Susan,

    Good points, but I don’t think you go deep enough in describing the relationship between Microsoft DHCP, DNS and AD. It would be nice to describe <why> "things just work ‘better" so it’s not just a subjective observation.

    Karen has been kind enough to repost on her website a digest of my presentation/discussion at one of the local SBS meetings on the relationship between these three Microsoft networking services which I dubbed "The Troika."


  2. Hi all,

    Just remember that if you use the SBS DHCP, you *must* make sure that the primary DNS it allocates is the SBS server, otherwise workstations in the domain take forever to log in. I always make it a practice to throw my DHCP options into the "server" properties, not the "scope", just in case I have to fiddle with ranges. Reserving IPs for printers is also a great idea, as this helps do a quick swap on the failure of IP cards in printers, say…Lexmark (not naming names of course).

    My standard DHCP options…

    Router (SBS if you’re using ISA, else DSL/Cable IP)

    DNS server (SBS first, then externals)

    Domain Name (xxx.local or xxx.lan)

    WINS server (SBS)

    WINS type (0x8)



  3. thatsright23 says:

    i am trying to get my ps2 online and it asks for my dhcp wut do i put in?

  4. Ryan says:

    Any one got a good way of telling that my SBS box is not my DHCP. The reason why I ask is if I disable the DHCP on my wireless router. Then add the clients the computers just make up there own IP’s. Which makes me think that the DHCP is off on the router.

    Then if I leave the DHCP on the router. The server gives it’s self & the router does the same. Which I believe screws up domain resolution, the http://companyweb/“>http://companyweb/ (i think this because if I type in http://companyweb/“>http://companyweb/ it takes me to my router page).

    I have run the CEICW like six times and it never asks me about my server not being DHCP. Which I was told it would! (The router is WGU624).


    Internet -> Modem -> SBS NIC 1

    SBSNIC 2 -> ROUTER -> Client(s)

    Please let me know if I need to be more specific.

  5. Eddie says:


    Judging from you diagram the router’s in the wrong place.

    The router goes between the modem and Nic1.