Problem Statement

The increasing demand for IPv6 addresses and IPv6-based services is prompting SPs to build an IPv6 network. However, their current network is an IPv4 network with MPLS running on it. The question is, "How best can they continue to offer the existing portfolio of IPv4-based services and layer IPv6 services with it?" Some of the questions providers must ask are:

• Can I build IPv6 edge services without changing the existing IPv4 network core?

• Can I build IPv6 VPNs without changing the IPv4 network core?

• Do I need MPLS? Hence, do I need Label Distribution Protocol (LDP) and Resource Reservation Protocol (RSVP) to be IPv6-capable?

• Can I build an entire network just with IPv6 and layer MPLS on it?

This chapter explores the answers to these questions in some depth. It is not the aim of this chapter to explain exactly why an SP needs to deploy IPv6 or to describe the benefits of IPv6. The Assumption is that SPs need IPv6, and this chapter aims to discuss how an MPLS-based network can carry IPv6 traffic or help provide IPv6 services.