Ethernet problem (may be caused by Parallels)

Question

Everything on my iMac was working fine, and I was using Parallels for Outlook and all of my usual Mac apps, including Safari. Then, internet access for the Mac apps stopped working, although internet access through Parallels continued to work. I rebooted several times, tried network diagnostics, and renewed my DHCP lease.
But here is where I am now:
- My DSL works fine, because I can access the internet through other computers
- The Ethernet connection itself works when I plug it into other Macs
- When using Parallels on my iMac, I can access the internet
- When using Mac applications on my iMac through my usual Ethernet connection, I can't access the internet. However, it works on this computer wirelessly.
Does anyone have any ideas how I can get my iMac to access the internet through this Ethernet connection again, as it did before?

Answer 1

I had this problem once while I was travelling. I found I could use ethernet through Parallels or Mac OS, but not both. At the time, I blamed Comcast, and just kept rebooting until the ethernet worked in the OS in which I wanted it to work...
But, while I still blame Comcast I have since realized what I should have tried, so perhaps you can be the guinea pig. Parallels has various ways of contacting the internet. The default method is that it creates its own socket or something for accessing the internet, which has its own IP address. I wouldn't be surprised if this is creating the exclusivity you are observing--one ethernet cable equals one IP address so either Parallels has an IP address with internet or Mac OS does, but not both. So instead tell Parallels to use the Mac OS ethernet connection (Shared Networking). To configure this, I think you have to shut down Windows, and then, with the Virtual Machine window up, select Edit > Configure > Networking. See p. 157-8 of the Parallels User Guide.