CCNP SP MPLS FAQ: Virtual Private LAN Services
Q1. As which kind of port type can the customer-facing Ethernet interface on the PE router be configured?
Answer: The customer-facing Ethernet interface on the PE router can be configured as any of the following:
- An access port
- An 802.1Q trunk port
- A dot1qtunnel port
Q2. How many labels are used to forward VPLS traffic, and what is the use of each of those labels?
Q3. What does VFI stand for?
Q4. Which Layer 2 control protocols can be tunneled across the VPLS network?
Q5. Why do the PE routers need to be in a full mesh of pseudowires in VPLS?
Q6. Name the six functions that VPLS performs in emulating an Ethernet switch.
Answer: VPLS performs the following six functions in emulating an Ethernet switch:
- Forwarding of Ethernet frames
- Forwarding of unicast frames with an unknown destination MAC address
- Replication of broadcast and multicast frames to more than one port
- Loop prevention
- Dynamic learning of MAC addresses
- MAC address aging
Q7. In which two ways can H-VPLS be implemented?
Q8. Name the two major implementation models that describe Virtual Private Network (VPN) connectivity.
Q9. Name two possible business problems that can be solved by using a VPN.
Q10. In the peer-to-peer model, describe the difference between a C network and P network.
Q11. Describe two advantages that the peer-to-peer model provides that the Overlay model does not.
Q12. Using the Overlay model, what is the formula to calculate the number of VCs required between a set of client sites if a full-mesh topology is deployed?
Q13. List three technologies that provide IP-based Overlay VPN connectivity.
Q14. Why is the hub-and-spoke topology most often used when the Overlay model is deployed?