All of a sudden my iMac in my office connected by ethernet cannot connect to the internet. My network is up and running as I can use my office iMac to access other computers (such as my Macbook) on the wireless network. I have a Time Capsule functioning as my router.

All the computers connected wirelessly (my macbook and my wife's iMac) are connected and can access the internet.

I've rebooted and reconnected the ethernet cable a couple of times already. I have also connected via the Airport on the affected iMac which works fine in connecting to the network, but still I can't get online.

I've tried shutting down and restarting my DSL modem already. I'll try shutting down the TC as soon as it finishes a wireless backup from my wife's iMac.

Any other thoughts?

 

Waiting for Obama to pay your bill?

 

No...I'm waiting for him to fix teh interweb!

 

Did anything change in your network config? If you've rebooted it, that should eliminate most OS X networking gotchas.

Open a terminal (Apps -> Utilities -> Terminal) and see if you can ping the gateway. You can find the address in System Prefs -> Network ->Ethernet, and the IP you want is under "Router".

A successful ping will look like this:

Hit CTRL + C to terminate the ping.

 

Thanks Simba, but I was able to connect after restarting my DSL modem and the TC.

I assume it as some issue with DHCP allocated IP address issue with my DSL provider?

What was weird was that just restarting the DSL modem, rebooting the iMac, connecting via the Airport (with the Ethernet disconnected) all didn't work. The only different was that I connected my Macbook via ethernet to the TC to facilitate downloading the MacOS update. The Macbook ethernet connection worked, but my iMac's internet connection suddenly failed. This hasn't happened before.

Oh well...

 

Could be, if your provider supplies a router that acts like a bridge, and assigns real IPs to your host machines. Most just do a NAT with one real IP.

Sounds like an IP conflict or NAT problem. You'll want to check out the TC config and see if it's assigning private addresses and doing NAT, or trying to bridge and distribute real addresses, or what.

 

It should be doing NAT right?

 

Ideally, yes. Also, if you have another device in the chain, a router or your DSL box for example, that is also doing NAT, that can cause problems.

If you do have another gateway box, the solution may be to give the TC a static IP on the NAT network that is being distributed by said gateway box.