Overlapping VPNs are generally used to connect parts of two separate VPNs. A third VPN is created within the MPLS VPN network that contains sites from both VPNs. A new RT extended community is used for networks that originate in the sites that are also in the new VPN. This action might require a new VRF instance, resulting in a new RD. Networks that originate in these sites are exported with two RT extended communities: one for the original VPN, and one for the overlapping VPN. In this course, you will learn about the requirements, usage, and solutions that are associated with overlapping VPNs. You need to understand customer needs and how to best meet those needs. In this course, you will look at an area that helps to clarify some solutions regarding multiple separate VPNs. A central services VPN is used when multiple VPNs need to share a common set of servers. These servers reside in the central services VPN, and all other VPNs have access to this VPN. The other VPNs, however, are not able to see one another. The central services VPN is implemented using two RT extended communities, where one imports networks into the VPN and the other exports networks. The client sites do the opposite. Two RT extended communities are needed to prevent client sites from exchanging routing information. In this course, you will look at central services VPN solution topologies and how routing updates within that topology would flow. You will also learn about the implications of combining a central services VPN with an overlapping customer VPN. It is important to fully understand the topologies that make the most sense for the customer and to be able to configure or recommend other options. Some VRF features allow you to be more selective with routes, by specifying which routes will or will not be added. You can also limit the number of routes that a customer can insert into the VRF instance. You will learn about the command syntax that is used to limit each type of route. It is important to understand how to fine-tune the MPLS VPN parameters that will enhance the operation of the network. Customer SLAs should be adhered to so that they provide the best possible solutions for each specific customer. You will learn about some important areas regarding the use of VRF import and export features. A service provider can use a separate network management VPN to manage the CE routers of all the VPNs. A pair of RT extended communities is used to accomplish this goal. One RT exports CE router loopback addresses and is imported into the VRF of the network management VPN. The other RT exports the networks from the VRF that is associated with the network management VPN and imports them into all other VRFs. In this lesson, you will learn about some of the requirements and the implementation solution for the managed CE routers service. It is important to be able to recognize the requirements of the network and to match them with customer requests. You will take a look at one such requirement and explain how to handle it.

In this course, you will learn about common customer Internet connectivity scenarios and about two design models for combining Internet access with MPLS VPN services. You will also learn about the benefits and drawbacks of these models, and the implications of their use. This course is crucial for students who plan to enhance their use of network resources by using MPLS VPNs. You will learn about Internet access services in the MPLS VPN environment. Understanding why you might choose to use global routing to separate Internet access from VPN services is important. You will identify the PE-CE requirements for separating Internet access from VPN services and identify how to implement the solution in an MPLS VPN network. You will also learn about the characteristics of Internet access solutions in which the Internet access is provided as a separate VPN. This course is crucial for students who plan to improve their use of network resources by using MPLS VPNs.