110 likes | 251 Views
Prefix Delegation Protocol Selection. T.J. Kniveton MEXT Working Group IETF 70 - December ’07 - Vancouver. Presentation Outline. Problem Statement and Overview NEMO Drafts Other Reference Documents Working Group Discussion and Conclusions MEXT Charter Items Questions.
E N D
Prefix DelegationProtocol Selection T.J. Kniveton MEXT Working Group IETF 70 - December ’07 - Vancouver
Presentation Outline • Problem Statement and Overview • NEMO Drafts • Other Reference Documents • Working Group Discussion and Conclusions • MEXT Charter Items • Questions
Problem Statement and Overview • If your Mobile Router is not statically pre-configured, how can you request and receive a prefix for your mobile network? • Lifetime could be long-term, or for the session • We could be dealing with the consumer case, or the fully-enabled router case • Consider the implications of a host auto-configuration environment, and of a managed, stateful address configuration environment • Note: Autoconf is now considering a similar issue for prefix delegation in connected/standalone MANETs
NEMO Drafts:DHCPv6-based Prefix Del. (1) • Submitted 6/2003 • Uses existing DHCPv6 infrastructure, and Prefix Delegation option as defined in RFC 3633 • HA acts as Delegating Router or DHCPv6 Relay Agent and MR acts as Requesting Router • HA must act as DR for MR but can be RA for • AR can also act as DR
NEMO Drafts:DHCPv6-based Prefix Del. (2) • The HA and MR exchange DHCPv6PD protocol messages through the tunnel, using link-local multicast and unicast addresses • The tunnel acts as the link labeled “DSL to subscriber premises” from DHCPv6PD specification • Provides a starting point for designing a DHCPv6-based solution.. but does it provide enough details for an implementation?
NEMO Drafts:NEMO-based Prefix Del. (1) • Submitted 10/2004 • Proposes new BU bit, BAck bit, and three BU options • The HA is required to be involved in authenticating and authorizing MNPs as it is for HAddrs--but more important here due to properties of routing prefixes • Idea: IPv6 networks are designed for autonomy and mobility. A “chunk” of v6 prefix space can be delegated to the HA one time, or managed by a routing protocol, and the HA will manage the prefixes along with mobility for consumer devices • Consistent with routing protocols and address auto-configuration. Simple MRs can be implemented that are not required to be Requesting Routers and connect to DHCPv6 infrastructure to operate. Idea: HA handles complexity and flows are optimized to provide complete prefix info • There is not necessarily a need to run a pool of servers that actively manage the address space. It can be a function of the HA
NEMO Drafts:NEMO-based Prefix Del. (2) • Allows delegation of prefixes from HA to MR on a temporary or permanent basis • Allows a MR to request a full list of prefixes. Bootstrapping, expired prefixes, newly allocated prefixes, newly allocated prefixes, prefix life association with the binding lifetime are supported by this approach • Prefix Delegation messages are included in normal NEMO protocol flow, with additional flags defined • Message flow is optimized to improve mobility aspects of the protocol • No need to deploy DHCPv6-based infrastructure • Authentication is included as part of MIP/NEMO protocol flow • Back-end can be supported by HA and provided with a common NEMO interface • Assumes that HA is tied into back-end infra, or has been assigned a super-prefix, just as it has already obtained prefix(es) for HAddr’s • Routing protocols, AAA backend, DHCPv6 can be used. • Bottom line is that HA is considered part of the routing infrastructure and is able to request/communicate prefix routing info for the MRs. This is the basic assumption. • Why not a DHCPv6-based solution? • Please see the draft, section 4.4
Other Reference Documents • RFC 3633 – DHCPv6 Prefix Delegation Option • RFC 3769 – Requirements for IPv6 Prefix Delegation • draft-sarikaya-16ng-prefix-delegation-02 • DHCPv6 prefix delegation in 802.16 networks • draft-sarikaya-netlmm-prefix-delegation-01 • DHCPv6 prefix delegation in PMIPv6 • draft-sarikaya-dime-prefix-delegation-ps-00 • Using AAA (diameter) to manage prefix mgmt for backend • A couple of expired drafts on ICMPv6-based prefix delegation
Working Group Discussion and Conclusions • NEMO-based PDel and DHCPv6-based PDel were accepted as working group items. • Neither document proceeded to RFC • Solicitation for implementor feedback did not yield much input • Pushback on bringing two documents to the IESG • Because of lack of feedback between the solutions, we did not advance one draft or the other • Recent discussion on MEXT ML on this topic
MEXT Charter Items • Deliverable: • (B.3) Finish working group documents that are currently in process, andsubmit for RFC. This includes prefix delegation protocol mechanism for network mobility, and a MIB for NEMO Basic Support. • Milestone: • Mar 2008 Submit the final doc on Prefix Delegation for NEMO to the IESG, for Proposed Standard
Questions • How does MEXT want to reconcile the two NEMO working group drafts? • Do we want to assume that DHCPv6 will be present whenever prefixes are delegated? Is this the only way to scale HAs? • How far do you want to go with describing the system in these drafts? • If NEMO Prefix Del draft is a starting point, do you want to consider the back-end mechanism further? How far up the food chain? • If DHCPv6 is assumed, do you want to extend DHCPv6 to allow for additional NEMO-specific features, or do you want to drop some of the features in NEMO Prefix Del? • What should be said about AAA managing address space, if anything?