iMac & MacBook no Internet over LAN but WiFi works.

[Glumpfner]

Hi there,

I have a PC that is connected to the router via LAN cable. I have a MacBook Pro, which is connected via WiFi to the router. Both work.

Today I bought an iMac to replace my old Windows PC. Because I want the fastest internet speed possible, I prefer to use the LAN cable. Now comes the strange part.
My Mac gets a proper IP address assigned (192.168.1.40), but I can't connect to the internet. No website loads, nor can I ping anything.
I checked on the router (Zyxel NBG420N), no filters for LAN are set and in the client list of the router, the iMac is listed correctly. The only thing I have set are MAC filters for the WiFI, but that should not affect the LAN.
So I turn on the WiFi on the iMac and it works perfect. But as I said I want to use the LAN cable.

I now noticed same thing on my MacBook Pro. When I use WiFi, all works. When I plugin the LAN cable, I get an IP address assigned, but no websites load and I can't ping anything, as if there is a problem with the DNS.
I also tried setting 8.8.8.8,8.8.4.4 as DNS servers, but didn't help.

Even stranger, on my old Windows XP machine, the LAN cable works without a problem. Plug and Play. I also checked the LAN settings on my Windows PC, its all set on DHCP/Automatic, no extra settings.

So it seems since the Windows PC works but neither the MacBook Pro (10.6) nor the iMac (10.7) that it's a MacOS X related problem.

 

[Glumpfner]

Maybe I should rephrase it.

Does anyone know why when I connect my MacBook Pro/iMac via LAN cable to my router, I get an IP address assigned, but cannot actually get into the internet? As if the DNS server is not responding. WiFi works perfectly.