Virtual PortChannel Technology Virtual PortChannels (vPCs) allow links that are physically connected to two different Cisco® switches to appear to a third downstream device to be coming from a single device and as part of a single PortChannel. The third device can be a switch, a server, or any other networking device that supports IEEE 802.3ad PortChannels. Cisco NX-OS Software vPCs and Cisco Catalyst® Virtual Switching Systems (VSS) are similar technologies. For Cisco EtherChannel technology, the term “multichassis EtherChannel” (MCEC) refers to either technology interchangeably. vPC allows the creation of Layer 2 PortChannels that span two switches. At the time of this writing, vPC is implemented on the Cisco Nexus® 7000 and 5000 Series platforms (with or without Cisco Nexus 2000 Series Fabric Extenders).
One of the key differentiators between the two technologies is that port channels support both Layer 2 and Layer 3. vPC on the other hand only supports Layer 2.