Why is it that if my service provider has an outage (e.g. a fiber cut) due to damaged or faulty equipment outside my building (beyond my carrier's demarc switch, which my router plugs into), I do not see my CE router's interface status change, my FE/GE WAN interface remains up/up (I can tell that my service is down, because BGP goes down and I'm no longer receiving my ISP's PE MAC address), however, on other CE routers of ours, which have a TenGig WAN interface, if there is an outage outside of our building, I do see our interface go down/down?
It's as though the TenGig Ethernet interface behaves more like a Serial interface, where if there is a break anywhere along the path we will see our WAN interface go down/down.
