Nexus - vPC

vPC is a technology offered by the Nexus platform to allow virtual port channels between Nexus switches without having to use stack-wise technology.

vPC peer switches: Switches Nexus7K-1 and Nexus7K-2 need to run Cisco NX-OS and have the "feature vPC" enabled to run the vPC protocol.

vPC peer link: Must run a portchannel using 10G links using 802.3ad. This link runs a modified Spanning Tree Protocol weight and tags packets as having originated on the local peer using the peer link.

vPC peer keepalive link: The peer keepalive link is a logical link that often runs over an out-of-band management network. It provides a Layer 3 communications path that is used as a secondary test to determine whether the remote peer is operating properly. No data or synchronization traffic is sent over the vPC peer keepalive link, just a frame that indicates that the originating switch is operating and running vPC.

vPC member port: A vPC member port is a physical port on one of the vPC peer switches that is a member in a vPC. To have a running vPC instance, at least one PortChannel is needed with a member port on each peer switch.

Cisco Fabric Services: The Cisco Fabric Services protocol is a reliable messaging protocol designed to support rapid stateful configuration message passing and synchronization. vPC services use Cisco Fabric Services to transfer a copy of the system configuration for a comparison process and to synchronize MAC and Internet Group Management Protocol (IGMP) state information between the two vPC peer switches.