Connect MacBook Air to Cisco 2811 Console (RS-232 serial) I'm trying to console connect into my business's Cisco 2811 console with my MacBook Air with a Thunderbolt to Gigabit adapter. I've googled around for a day and haven't found any information.

How can I connect to my router with my MacBook Air using the Thunderbolt adapter?

EDIT:
I've purchased the proprietary Cisco console cable which is an RJ-45 to DB9 rollover 
cable.
Then I purchased a DB9 to usb adapter to plug into the MBA but when I try to follow 

http://www.cisco.com/en/US/docs/routers/connectedgrid/cgr1000/hardware/cgr1240/app.console.html#wp1049053

I don't get anything under usb.
Serial is not Ethernet, these are two different protocols, so connecting it to your thunderbolt adapter won't work. You can use a USB-serial cable for this, I've had good experiences with cables with a PL2303 chipset on OSX.