Current State of IPv6
For most organizations, IPv6 has not been much more than a new set of letters and numbers to toss around when talking about networking. Now, however, more of the specifications are becoming finalized, many are IETF draft standards, and many more are proposed draft standards. IANA allocated address space to the regional Internet registries (RIR), and the RIRs have begun allocating address space to Internet providers. Network and end-station equipment vendors have begun releasing software that supports IPv6, or have announcednear-term plans to offer support. A large test network, the 6bone, exists to allow organizations to try out their IPv6 implementations, to learn how to transition their networks, and to get used to managing them. A public production network, 6REN, also exists for research and education institutions ready to deploy production IPv6 networks. Network planners may begin to think more about IPv6 as it becomes more readily available and easier to implement. CCIE candidates should be ready to tackle IPv6 as well.
IPv6 Specification (RFCs)
The IPv6 specification is now an approved draft standard. Companies have released (or prereleased) products based on the specifications. Current draft standards include the following:
RFC 2373: IP Version 6 Addressing Architecture RFC 2374: An IPv6 Aggregatable Global Unicast Address Format RFC 2460: Internet Protocol, Version 6 (IPv6) Specification RFC 2461: Neighbor Discovery for IP Version 6 (IPv6) RFC 2462: IPv6 Stateless Address Autoconfiguration RFC 2463: Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification
Many components of IPv6 are currently proposed draft standards that are awaiting approval, including the following:
RFC 1886: DNS Extensions to Support IP Version 6 RFC 1887: An Architecture for IPv6 Unicast Address Allocation RFC 1981: Path MTU Discovery for IP Version 6 RFC 2080: RIPng for IPv6 RFC 2473: Generic Packet Tunneling in IPv6 Specification RFC 2526: Reserved IPv6 Subnet Anycast Addresses RFC 2529: Transmission of IPv6 over IPv4 Domains Without Explicit Tunnels RFC 2545: Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing RFC 2710: Multicast Listener Discovery (MLD) for IPv6 RFC 2740: OSPF for IPv6
There are many other proposed draft standards and related draft documents, and many more are expected in the near future, making it impractical to list them all here. You can find the RFCs at www.isi.edu or at many other RFC repositories.
Vendor Support
The protocol development of IPv6 and related components is far enough along in the standards process that vendors have committed to many development and testing projects. Cisco routers currently support IPv6 in a beta version of IOS based on version 12.1. They have announced IOS support in a later 12.1 release. Microsoft and Sun have IPv6 stacks available for end stations. Not all vendors support all IPv6 components. Some are waiting for the standards to mature; others are waiting for more customer pressure before committing the development resources to it. Upcoming large-scale applications, such as handheld wireless computers, may require IPv6, and vendors should at least have a plan for quickly implementing it. Cisco's IPv6 implementation currently supports the following features:
RIPv6 BGP-4+ for IPv6 IPv6 static routes Traffic filtering Automatic and static tunnels EUI-64 addressing Neighbor discovery IPv6 over Ethernet, FDDI, Cisco HDLC, and ATM PVCs Dual-stack support for Telnet, DNS, and TFTP ICMPv6 and Ping traceroute and debug commands
Implementations
There are two IPv6 implementations for public use. One, the 6bone, is used as a testbed for IPv6 issues. Protocol implementations, IPv4 to IPv6 transitions, and operational procedures have all been tested using the 6bone network. The other network, IPv6 Research and Education Networks (6REN), provides organizations with operational IPv6 networks to transit to other IPv6 networks. Both implementations have been instrumental in the IPv6 development process, giving vendors and network architects large-scale platforms on which to test software, network configurations, and designs, and on which to gain understanding and familiarity with the protocol.
6bone
The 6bone is a worldwide IPv6 network used for testing and preproduction deployment of IPv6 products and networks. It currently supports 260 organizations in 39 countries. The 6bone is designed to look like a global, hierarchical, IPv6 network. It contains pseudo top-level (Tier I) transit providers, pseudo next-level (Tier II) transit providers, and pseudo site-level organizations. The pseudo top-level providers are interconnected organizations around the world. Top-level providers communicate with each other using IPv6 extensions to BGP-4. Next-level providers connect to a regional top-level provider, also using BGP-4, and site-level organizations connect to the next-level providers. Site-level organizations can default route to their providers or use BGP-4. Connections were originally made by tunneling packets in IPv4 and transporting them over the Internet. Gradually, native IPv6 connections are now being made. The 6bone has proven to be a very instrumental testbed for IPv6 standards and products. Now it also is being used to test transitions and operational procedures. Figure 8-1 shows the 6bone backbone.
6REN
The 6REN voluntary coordination initiative is a production IPv6 network designed to provide transit IPv6 services. As stated at the www.6ren.net/overview.htm Web site, the 6REN goal is as follows:
…provide production IPv6 transit service to facilitate high quality, high performance, and operationally robust IPv6 networks.
The transit services are available to research and educational institutions and for-profit and not-for-profit organizations. Networks are interconnected with native IPv6 over ATM. 6REN provides connectivity to the 6bone participants as well.
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