Multichassis EtherChannel Topology Design
Question
An engineer is designing a Multichassis EtherChannel topology in which two switches must appear as a single device to a third downstream switch? Which two technologies meet this requirement? (Choose two.)
Answers
Explanations
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A. B. C. D. E.BC.
https://www.cisco.com/c/dam/en/us/products/collateral/switches/nexus-7000-series-switches/C07-572835-00_NX-OS_vPC_DG.pdfThe correct answers for the given question are B. VSS and C. vPC.
Explanation:
Multichassis EtherChannel (MEC) is a technology that allows a single logical EtherChannel to be created using multiple physical links from separate switches. It provides high availability and bandwidth aggregation across switches. In some cases, it is necessary for two switches to appear as a single device to a downstream switch. This is known as a single logical switch (SLS) and can be achieved using the following two technologies:
Virtual Switching System (VSS) VSS is a Cisco proprietary technology that enables two physical switches to be combined into a single logical switch. The two switches act as a single switch with a single control plane and a single management IP address. The downstream switch sees the VSS as a single switch, and all traffic is load-balanced across both switches.
Virtual PortChannel (vPC) vPC is a Cisco technology that allows two separate switches to be configured in a way that they appear as a single switch to downstream devices. vPC is a layer-2 technology that enables a downstream device to form an EtherChannel with two separate switches. The downstream device sees the vPC as a single switch, and all traffic is load-balanced across both switches.
HSRP (Hot Standby Router Protocol) is a Cisco proprietary protocol that provides redundancy for IP networks. HSRP allows multiple routers to participate in a virtual router group to present the appearance of a single virtual router to the hosts on a LAN. However, HSRP does not provide a way to combine two switches into a single logical switch.
802.1q is a standard for VLAN tagging. It does not provide a way to combine two switches into a single logical switch.
FEX (Fabric Extender) is a technology that allows a remote line card to be connected to a parent switch using a proprietary protocol called FabricPath. FEX extends the parent switch's capabilities and provides a way to scale the number of ports in a switch. However, FEX does not provide a way to combine two switches into a single logical switch.
Therefore, the correct answers are B. VSS and C. vPC.
