300-420 Question 158
Single answerA large enterprise is planning to interconnect multiple branch offices over a Layer 2 VPN to maintain seamless connectivity for their VLANs. The design requirements include extended VLAN support, MAC address learning, and the ability to connect to third-party service provider networks. Which Layer 2 VPN technology would best meet these requirements?
- A
Virtual Private LAN Service (VPLS)
- B
Point-to-Point Protocol over Ethernet (PPPoE)
- C
MPLS-based Ethernet over MPLS (EoMPLS)
- D
GRE Tunneling
Show answer and explanation
Correct answer: A
Explanation
Virtual Private LAN Service (VPLS) is the most appropriate Layer 2 VPN technology for interconnecting multiple branches over a service provider network while maintaining VLAN continuity and MAC address learning. It supports multipoint-to-multipoint connectivity, making it ideal for enterprise scenarios requiring seamless Layer 2 connectivity across multiple sites.
- A. Correct.
VPLS is a Layer 2 VPN technology that supports extended VLANs, MAC address learning, and interoperability with third-party service provider networks, making it suitable for the described requirements.
- B. Incorrect.
PPPoE is primarily used for encapsulating PPP frames within Ethernet frames and is not a Layer 2 VPN technology designed for interconnecting branch offices or supporting VLANs.
- C. Incorrect.
EoMPLS is a good option for point-to-point Layer 2 VPNs but does not scale well for multi-branch connectivity and lacks some VPLS capabilities like MAC address learning in a multipoint fashion.
- D. Incorrect.
GRE Tunneling is a Layer 3 tunneling protocol and does not meet the requirements for Layer 2 VPN connectivity or VLAN extension.