Which statement about the overlay VPN model is true?
Click on the arrows to vote for the correct answer
A. B. C. D.C.
The overlay VPN model is a virtual private network ( VPN) model that is used by service providers to provide VPN services to their customers. In this model, the service provider overlays a VPN network on top of its existing infrastructure to provide secure and isolated connectivity between the customer sites. The overlay VPN model uses techniques such as tunneling, encryption, and encapsulation to provide this secure connectivity.
Now, let's look at each answer option:
A. The statement is true. The overlay model demands a lot from provisioning because when adding one customer site, it demands many configuration changes at many other routers on the provider side. This is because the overlay VPN model requires the service provider to configure a large number of tunnels and security policies to ensure secure and isolated connectivity between the customer sites.
B. The statement is false. The overlay model can scale to the same size as the MPLS VPN model, but it may require more configuration and management overhead.
C. The statement is true. The overlay model provides the ability to reduce the amount of routing state that core routers need to hold to meet the scalability requirements compared to the MPLS VPN model. This is because the overlay model uses tunneling to encapsulate the customer traffic, reducing the amount of routing information that needs to be exchanged between the service provider and the customer sites.
D. The statement is false. The overlay model provides privacy and isolation between the different customers by using virtual routing and forwarding (VRF) instances, not packet filters. VRF instances enable the service provider to create separate routing tables for each customer, ensuring that their traffic is isolated and secure.
In summary, the overlay VPN model is a popular VPN model used by service providers to provide secure and isolated connectivity between customer sites. While it may require more configuration and management overhead compared to other VPN models, it provides the ability to reduce the amount of routing state that core routers need to hold and ensures that customer traffic is isolated and secure using VRF instances.