Service-edge routers must support both layer 2 traffic (which requires interoperability with frame relay and ATM devices) with the same level of service guarantees as layer 2 devices, as well as new, ...
I've got AT&T fiber and am using an ERX SFP in IP passthrough mode. I had IPV6 working fine with my previous cable service, and it was working with AT&T but I just noticed my LAN interfaces aren't ...