2

The question is essentially in the title - I'm very new to servers and AD (studying for my first exam as of now and messing with VM's). My query is really, with DHCP installed in your domain, will it only dish out IP's and DNS details to domain joined computers? Would that mean in order to connect a machine to a domain you would need to configure static IP's since routers would naturally have DHCP switched off? And if this isn't the case, whats the benefit of using DHCP with AD if you can just control DHCP through your router (that is if DHCP isn't restricted to domain members only).

Thanks!

EDIT: For example - even if a non-domain joined computer connected up to the network on say a wireless AP (with DHCP fed to it from the DC itself with DHCP installed), it would still use the DC as the DNS server (ofc if it's setup this way) ?

PnP
  • 1,684
  • 8
  • 37
  • 65

2 Answers2

6

It will dish out an IP address and DNS server addresses to any computer on the same broadcast domain (ie. any contiguous network infrastructure not separated by a router). You would not need to configure a static IP before you joined a computer to the domain. See also: How does a computer obtain an IP address via DHCP?

The advantage of running DHCP on a domain controller is that AD, DNS, and DHCP integrate very well together. DHCP will update the computer's name and IP in DNS, and it will replicate to all of the other DC/DNS servers in your organization. However, it would also make sense to run DHCP on a network device (to me, this would make the most sense since receiving an IP address is network-related), but I don't know if this would have any shortcomings versus running it in an AD/DNS environment.

Community
  • 1
Bigbio2002
  • 2,763
  • 11
  • 34
  • 51
  • So for example - even if a non-domain joined computer connected up to the network on say a wireless AP, it would still use the DC as the DNS server (ofc if it's setup this way) ? – PnP Jun 07 '12 at 19:05
  • 1
    @user1048116 yup. DHCP has no concept of (AD) "domain" - It just knows "I hear broadcast request for IP. I reply with broadcast offer of lease". [RFC 2131](http://www.ietf.org/rfc/rfc2131.txt) has all the gory details. – voretaq7 Jun 07 '12 at 19:08
  • 1
    Correct. DHCP works at the network layer, and the client computer will use whatever DNS server is given to it by DHCP. Domain authentication is a higher-level construct. – Bigbio2002 Jun 07 '12 at 19:10
  • I much appreciate all the replies here, thanks a lot! – PnP Jun 07 '12 at 19:45
1

DHCP is what I would call "Windows Agnostic" in that it will serve basic network configurations to any client that can speak DHCP. There are some OS specific tricks you can do with DHCP (like PXE/RIS) however it doesn't affect basic connectivity for the vast majority of clients.

AD integrated DHCP allows AD to be aware of any new network devices. That is where the benefit comes in as AD is DNS reliant and the ability to automatically add network devices to DNS makes life easier for the administrator.

jfalcon aka Don Fanning
  • 346
  • 1
  • 8