Something seems to be wrong in your configuration, as in both cases the IP address of the ETH01 is the same, which doesn’t make sense. On the first case you should have a public IP assigned by your cable internet provider. On the second case this public IP is assigned on your border router. Can you verify that your cable provider is indeed sending DHCP?
tcpdump -i ETH01 -w /Database/test.pcap
Use this command to capture the traffic of ETH01. It quits with Ctrl-c. Make sure you use it when you power up the cable modem so that the DHCP packets are captured.Transfer it with ftp to your pc and upload it here.