I have a working set up (using the original firmware) where my wrt3200 ACM is connected to the internet through its WAN port, plugged into an Xfinity router, which has been configured into bridged mode.
I successfully installed OperWRT latest version, but was not able to connect the router to the internet through the WAN port (all the rest was working fine), and did not have the switch menu available to try hacking... So luckily I was able to revert by booting the original partition from ssh.
Can someone kindly advise what I may be missing, to have my setup working with OpenWRT as well?
Yep... I too was expecting it to work out of the box, just like with the original firmware.
The WAN Mac is exactly the same in openwrt as in the original firmware.
No double NATing, just the connection to the bridged router to Xfinity cable on one side and my internal 192.168.1.1 network on the private side.
Also, I did not changed anything in the setup, in fact reverting to the original partition just restored everything working like as if I didn't even flash openwrt.
Moreover, I also did not do any fancy changes in openwrt: I just installed it, configured the administrative password and set up the Wi-Fi connections (letting them disabled).
In the interfaces I can see are the LAN, WAN and Wan6 interfaces (btw, no switch menu!!). The WAN has the same Mac address but does not have any IP address assigned to it.
All the LAN/WI-FI interfaces work okay in the private Network... Just the WAN does not connect to the internet...
Thanks, yesterday night I did that like at least 10 times, with different intervals up to 20 minutes, because I thought there was something cashed in the bridge router... But no luck.
The very strange thing was that as soon as I reverted the partition with the original firmware everything worked perfectly without the need of any restart.. . And even stranger we're talking about the same physical hardware connected... And the rotor itself is showing that it is connected to the internet through its LED.
maybe try disabling wan6 and ipv6 on the wan interface.
i think that even though the WAN ipv4 mac may be the same, the cable modem might be looking for a persistent ipv6 adress downstream, which might be different in openwrt than the oem firmware. and did you power down your cable modem for long enough that it might 'forget' the downstream hardware?
I finally got this solved: I turned off the xfinity modem and just left Costco-ing, when I came back, I turned it on and... voila'!!
It was indeed some ipv6 caching of some sort as @psherman and @ghoffman suggested.