CCIE RS Workbook | CCIE Security Workbook | CCIE SP Workbook| CCIE Voice Workbook
This chapter covers IPv6 unicast connectivity within an enterprise or service provider network, and discusses available options, implementation scenarios, and deployment recommendations. The intent is to present this information as it applies to different parts of the network:
The concepts that are relevant in making a host operational in an IPv6 network are presented first. This section of the chapter reviews the mechanisms for providing hosts and CE routers with an IPv6 address, and introduces new concept such as prefix delegation, for providing name-resolution support and for some AAA (authentication, authorization and accounting) management.
Subsequent sections discuss the delivery of IPv6 unicast connectivity from a network perspective. The service deployment will most likely interact at some point with or over some segments with existing IPv4 infrastructures. In this interaction, there are three deployment approaches:
These three approaches define a framework for the service deployment strategy. The technological means to implement them are presented in the context of the two relevant layers of the network: access and backbone.
Table 3-1 summarizes the deployment mechanisms presented in this chapter. Along with the scope and significant features, the table lists the areas of the network where the mechanism would fit best.
Simplest method in terms of setup.
Support on all network elements in the path.
Bridged (IPv6 RBE)
IPv6 RBE routes the IPv6 traffic out of a bridged ATM encapsulation.
IPv6 over MPLS
It is a native method where a physical or virtual link interconnects two sites.
MPLS infrastructure. IPv4 Label Switch Path setup. IPv6 transport over MPLS.
Applicable to MPLS infrastructure only. IPv4 and IPv6 traffic follow the same paths.
MPLS infrastructure. Native IPv6 Label Switch Path setup. IPv6 transport over MPLS
MPLS only. LDP and RSVP IPv6 implementation not available.
Static, supported by most IPv6 implementations.
Tunnel endpoints can be secured with IPv4 IPsec.
Tunnel broker and tunnel server
Provides the means to automatically set up configured tunnels upon request. A dedicated device or a router performs this function.
Potential security implications.
Works through multiple NATs.
Static. It supports the transport of layer 2 multicast, which is important for the control plane of some protocols (IS-IS).
Performance. No solution for multicast.
6 to 4
Automatic tunnel. Reserved address space 2002::/16.
Return path selection not optimized.
Security issue if not secured through IPsec.
These mechanisms are presented in this chapter along with more in-depth discussions on deployment recommendations. The recommendations are made only from the perspective of providing IPv6 unicast connectivity. Other selection criteria are presented in the chapters dedicated to other services, such as multicast, virtual private networking (VPN), quality of service (QoS), and security.
Overall, a deployment strategy choice depends on technical considerations (best way to leverage existent IPv4 infrastructure and to circumvent constraints such as Network Address Translation [NAT], for example) as well as cost-effectiveness considerations (for instance, return on the investment of upgrading existent resources or adding new ones). Nevertheless, when possible, it is recommended to begin with native IPv6no IPv6 tunnelsbecause this represents the ultimate goal of the IPv6 integration.
As cisco instructors we provide this free offer to help any one who is interested in being a cisco certificate engineer . All the below tips are FREE!!!.