# Server 2012 Essentials with Router handling DHCP



## chewie1012 (Dec 27, 2001)

I am considering using a router for DHCP with a Server 2012 Essentials server. I am curious if this is acceptable and if so how would I configure DNS. I want the server to handle DNS but also would like to be able to get out on the internet. I should say that the router is a Comcast SMC Router and is not UPnP. Also the router has many ports forwarded for a camera system. It would be much simpler to leave the router as is. But if this is going to cause issues I would definately be willing to change things.


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## zx10guy (Mar 30, 2008)

What's your goal with running a local DNS server?


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## chewie1012 (Dec 27, 2001)

The server will be a domain controller. I think everything will function better with the server handling dns.


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## srhoades (May 15, 2003)

You do not have to change port forwarding at all regardless of whether the server or the router is handling DHCP. My advice is to let the server handle DHCP and create the necessary exemptions in the scope so your current devices that have a static IP are not affected.


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## chewie1012 (Dec 27, 2001)

Thank you both for responding. 
srhoades,
Will it matter if the router is not UPnP? Also as a side note I should say there are only 5 computers / users in the network and anywhere access will not be necessary.


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## zx10guy (Mar 30, 2008)

There are two schools of thought for where the DHCP server resides: on a network device or on a server. I've done deployments on both scenarios. The last system I built had a migration away from the AD server doing the DHCP duties and the core network switch picking it up. The setup was a building with 8 floors, about 500 ish workstations, and multiple network subnets. If I did the server route, I would have a number of challenges. One is the need to configure DHCP relays on the network to forward the DHCP requests from the various devices to the DHCP server. The other was the ability to do more with the network configuration I did. The Cisco 6509 switch I used for the DHCP server allowed me to have DHCP redundancy which was not possible with Windows server. The other feature the 6509 has was the ability to pre-ping an IP address it is about to assign to ensure there is no device on the network already responding to that IP. If there is, the switch just moves to the next IP in the scope and checks that for assignment.

You don't need to worry about UPnP. UPnP is a feature only found in the home market. You don't really ever see this in a business application. On my home network, I have a Cisco ASA5505 doing DHCP assignments without having to worry about UPnP nor have any of my large scale business network designs. I have about 15 to 20 different subnets which of them about 5 or so have DHCP scopes. I also have quite a few port forward rules setup on my SonicWall TZ215 and there are absolutely no problems.


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## chewie1012 (Dec 27, 2001)

Good Morning Zx10guy,
I will be installing these Server 2012 Essentials servers in smaller networks. What is your opininon on where to put dhcp and if it is to be left up to the router (one is a comcast business networks SMC Router and the other is a netgear Firewall Router) how would you configure dns? Would you let the server handle it or the router?


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## zx10guy (Mar 30, 2008)

Where to have the DHCP server run is personal preference. But I have to say with the routers you've mentioned, you will have limited configuration capabilities compared to what you can do with Windows Server. You may or may not need to set these additional options. Some of the additional options are if you need to configure parameters for a TFTP server as an example to be pushed to the DHCP client. This would be for devices like network devices which are configured to pull down their configurations from a central TFTP server or if you're using VoIP phones. From your description of the network environment, you probably won't need these additional parameters so it just comes down to which one you're more comfortable with.

As far as DNS goes, since you've set up a domain with a domain controller, you need to have all workstations which are part of the domain to have their DNS setting point to the domain controller/AD server. DNS is extremely important with AD. To help with the issue of resolving Internet domains, you need to configure the forwarder option in the DNS properties. In that window, you'll enter the IP address of either the router acting as a DNS proxy or the actual IP addresses of your ISP's DNS servers. I'd probably just put in the ISP's DNS servers there. I have this configured on my home network with no issues with AD and Internet name resolution.


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## chewie1012 (Dec 27, 2001)

Thank You! In the past I have let the routers handle dhcp and pointed to the server for dns. S12E supposedly is designed to go both ways. They mention having a UPnP router. This clears things up. Will I have to do anything with the ports on the server in regards to the camera system or is having them forwarded on the router with dhcp turned off going to work?


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## zx10guy (Mar 30, 2008)

No. You don't have to do anything further with the server. The only time you would have to do some configuration on the server in regards to the cameras is if the server was going to be set up as a web proxy or a router to replace the router you all ready have in place. The only function the server should be doing is just be the domain controller/active directory and DNS server for the network.


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## chewie1012 (Dec 27, 2001)

And DHCP per your suggestion correct?


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## zx10guy (Mar 30, 2008)

Again, if you want to move the DHCP function to the server. You don't have to. I'm a pretty firm believer of...."If it ain't broke....."


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