Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) v1.2VirtualizationHard
A network engineer is designing a highly available data center network using Cisco Nexus switches. The design requires multiple physical links between two Nexus switches to be aggregated into a single logical channel, providing increased bandwidth and redundancy. Which device virtualization technology allows for this aggregation while ensuring full active-active forwarding and loop prevention?
- AVLAN Trunking Protocol (VTP)
- BFabricPath
- CVirtual PortChannel (vPC)
- DSpanning Tree Protocol (STP)
Show answer & explanationAnswer & explanation
Correct answer: C. Virtual PortChannel (vPC)
Virtual PortChannel (vPC) is a Cisco Nexus feature that allows two Nexus switches to appear as a single logical switch to a third device (e.g., a server or another switch). This enables the aggregation of physical links from the downstream device to both Nexus switches, forming a single PortChannel. vPC provides active-active forwarding, bandwidth aggregation, and eliminates Layer 2 loops without blocking ports, significantly enhancing redundancy and performance in data center designs.
Why the other options are wrong
- A. VTP is used for VLAN management, not link aggregation or high availability.
- B. FabricPath is a Layer 2 multipathing technology but is distinct from vPC, which focuses on dual-homing a device to a pair of switches.
- D. STP prevents loops by blocking redundant links, which is not active-active forwarding.
Virtual PortChannel (vPC)
A Cisco Nexus technology that allows two Nexus switches to form a single logical PortChannel from the perspective of a downstream device.
- Enables active-active forwarding and bandwidth aggregation across two physical switches.
- Eliminates Layer 2 loops without blocking links.
- Provides redundancy for dual-homed servers or network devices.
Memory trick: vPC: Virtual PortChannels Create Redundancy.