Airport Extreme with Comcast Arris TM502G.  Cannot connect to internet

Hope someone can help.
I'm trying to set up an Airport Extreme with my iMac and am apparently having issues with the Comcast Arris TM502G.
Symptoms are:
1. When iMac is connected directly to Arris TM502 modem via an Ethernet cable, I have an internet connection.
2. When iMac is connected to the Airport Extreme via an Ethernet cable, which is then in-turn connected to the Arris Modem, I have no internet connection even though the Ethernet  port lights for both the connections are green.
3. The link light on the Arris modem blinks the same whether I have it connected to the iMac directly or through the Airport Extreme.

After searching Google, I've discovered there are quite few threads from people having the same issue, however, nobody seems to have a solution.  So here I am.

Heres the summary of the Airport Base Station:

Airport Tab:
Base Station Status: Internet Connection (Amber)
Version: 7.2.1
Serial Number: 6F70537TVZC
Airport ID: 00:19:E3:33:12:98
Ethernet ID: 00:16:CB:C1:87:54

Wireless Mode:  Create a wireless network

Connect Using: Ethernet
IP Address: 196.254.255.1

Internet Tab:
Connect Using: Ethernet
Configure IPv4: Using DHCP
IP Address: 196.254.255.1
Subnet Mask: 255.255.0.0
Router Address:  This field is blank
Ethernet WAN Port: Automatic
Connection Sharing: share a public IP address

Hoping someone has a solution.  So far, Ive tried resetting the modem, re-powering the modem, resetting the Airport Extreme.

It appears the modem and Airport can see each other, they just arent communicating in a way that will allow me to connect to the internet.