DNS/DHCP issue from the LAN

September 30, 2009 at 15:24:15
Specs: Windows Server 2008
I am having an issue with DHCP/DNS on a server (domain controller) I am currently configuring. The scenario is:

Router connected to the Internet is on
Domain Controller is on

The domain controller has its default gateway set to (the router) and DNS pointing to itself (DNS is installed with Active Directory and forwarders have been setup with web based DNS servers when local resolve fails). The domain controller has no issues with connecting to the Internet.

The domain controller is also running a DHCP server which is leasing IP addresses to clients in the LAN within the range to, the default gateway for the DHCP is set to the domain controller's IP address (

The problem: Although clients on the LAN can obtain a valid IP configuration from the server and ping the domain controller and other computers in the LAN, they can not reach the Internet. Interestingly (or not) nslookup does resolve the domain name i.e. google.com [] but pinging by DNS name or IP address does not work (host unreachable).

I have already switched off DHCP on the router and disabled the firewall on the router, LAN computer and the domain controller to no avail.

Any suggestions? If I am going about this the wrong way please let me know (or point me in the right direction, I'm happy to read/research further). Thanks.

See More: DNS/DHCP issue from the LAN

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September 30, 2009 at 15:43:22
Is the service Routing and RAS enabled and started on the server?

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September 30, 2009 at 16:48:07
"DNS is installed with Active Directory and forwarders have been setup with web based DNS servers when local resolve fails"

I take it you mean you set the ISP dns server ips in the forwarders tab? Can you ping those ips from the server? From the workstations?

The workstations dns entry is that of correct?

Do a tracert from a workstation to google.com and post where it fails.

BTW it isn't a matter of local name resolution failing or web based dns. There is a reason for the design as it is. MS wants a local dns server to resolve all names that are on the intranet. Any names on the internet to be resolved are passed by ms dns to the isp's dns servers for name resolution. You can think of it as a dns gateway just like tcp/ip has a gateway. This way the correct answer is given to the question and from the correct source.

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October 2, 2009 at 12:17:05
Hi, sorry for the very late follow up on this; had some other critical issues to resolve over the last couple of days.

It turns out that paulsep was correct. Although I had installed the Routing and Remote access service it had not started at bootup due to not being configured. I configured the service for Network Address Translation and everything is now fine, the LAN stations can reach the Internet via the settings assigned through DHCP.

Thanks as well to wanderer for your diagnostic suggestions which I attempted first (I assumed RAS would start on its own!).

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October 2, 2009 at 14:49:52
Great !!!

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October 2, 2009 at 15:32:39
What is the pc client default gateway set at ? It should be the router interface .254 .

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