Have a cisco 3750 running BGP across two circuits. Primary is a 100meg Ethernet from the main ISP, and the secondary is an Ethernet service provided by the data center we use. The secondary is billed for utilization only, and we never had a utilization bill, until last month. Seems we are using traffic across the backup circuit, even though the bgp log on the router doesn't show the primary being down. The last event shows: Last reset 3d22h, due to Interface flap - and usage on the secondary even today.
Unfortunately I'm no expert on BGP and was hoping for some suggestions on what to look for.