Which of the following logically combines ports from multiple switches into a single bundle?
a VRF instance
A virtual port channel (vPC) logically combines ports from multiple switches into a single port channel bundle. Conventional port channel, which are typically used to create high-bandwidth trunk links between two switches, require that all members of the bundle exist on the same switch. vPCs enable virtual domains that are comprised of multiple physical switches to connect as single entity to a fabric extender, server, or other device.
A virtual device context (VDC) does not logically combine ports from multiple switches into a single bundle. A VDC logically virtualizes a Cisco Nexus 7000 Series switch. A VDC is a single virtual instance of physical switch hardware. By default, the control plane of the Cisco Nexus 7000 Series switch is configured to run a single VDC. It is possible to configure multiple VDCs on the same hardware. A single VDC can contain multiple virtual local area networks (VLANs) and virtual routing and forwarding (VRF) instances.
A VRF instance does not logically combine ports from multiple switches into a single bundle. VRFs enable a router to maintain multiple, simultaneous routing table. Therefore, VRFs can be configured on a single router to serve multiple Layer 3 domain instead of implementing multiple hardware routers.
A virtual interface card (VIC) does not logically combine ports from multiple switches into a single bundle. A VIC is a Cisco device that can be used to create multiple logical network interface cards (NICs) and host bus adapters (HBAs). VICs such as Cisco M81KR send Fibre Channel over Ethernet (FCoE) traffic and normal Ethernet traffic over the same physical medium.