Domain network - DC cannot access Internet (nor can clients when wired-only)

Question

I am not well versed in networking in general but went ahead and attempted to convert my home workgroup in a domain. The domain controller (Win Server 2008) shows no errors in dcdiag, and machines can join to domain successfully. The DC has no wireless capability and is connected my WRT54G router.

My problem is that the DC has no access to the internet - for example, it cannot ping 8.8.8.8). I believe this is not an issue with the DC itself, as any client machine, when are wire-connected only, do not have internet access. However, when client machines connect to the network wirelessly internet works ok. It's like when wired the network is isolated and the wireless is some sort of DMZ... I may be saying something stupid, I don't know.

Anyway, what could cause this behaviour?

Answer 1

The WRT54G has a feature called AP Isolation located on the Wireless -> Advanced Settings page. It is also known as client isolation as it will prevent client to client connections. If this is the case, Disable this feature.

• Check whether default gateway : 192.168.1.1 is reachable in wired-only scenario.

• Check whether wireless IP : 192.168.1.x ping wired-only IP : 192.168.1.120 and vice versa.

• Check whether Wireless & Wired IP Configuration are AUTO or
  MANUAL. If you set Default Gateway for both adapter, it wont able to work with Wireless Wired together.

• Try Setting both Wireless and Wired AUTO (DHCP) and check what
  response you get.

• Take backup of WRT54G's settings, and Factory Restore it.

Do some trial and error accordingly, this should work!