vPC Data Plane Operation
vPC technology is designed to always forward traffic locally when possible. In a normal network condition, vPC peer link is not used for the regular vPC traffic and is considered to be an extension of the control plane between the vPC peer switches. The vPC peer link carries the following type of traffic:
vPC control traffic, such as Cisco FSoE, BPDUs, and LACP messages
Flooding traffic, such as broadcast, multicast, and ...