IETF #57 in Viena1 IPv6 Address Assignment and Route Selection for End-to-End Multihoming Kenji Ohira Kyoto University draft-ohira-assign-select-e2e-multihome-01.txt

IETF #57 in Viena2 Overview of our draft Goal: –Not an end host but each end application can decide a route. (End-to-end multihoming) Our proposal: –A multi-level hierarchical network model and address assignment. –A route is determined by selecting a pair of a source address and a destination address. –Selection is done on layer 4 or above, not on layer 3.

IETF #57 in Viena3 Hierarchical address assignment (assumption) Each ISP assign an address prefix to a site hierarchically. Our draft shows that this model can be extended to 3 or more level model. 2-level hierarchical model

IETF #57 in Viena4 Source address based path selection Selection of a pair of src/dst address immediately gives a path. –The number of candidate paths is the same as the number of src/dst pairs. An end application can select a path without full-route information. This enables: –Redundancy Speedy path alternation initiated by end host/applications. Independent of L3 routing protocols. –Load sharing Each end-to-end flow can use multipaths. src: M:A:s, dst: M:B:t src: L:A:s, dst: M:B:t

IETF #57 in Viena5 Implementation of site-exit router selection (1/2) Source address based routing is employed in a site Site-exit router selection is done by selecting a source address (see draft-huitema-multi6-hosts) Such a selection is done on L4 or above –Host/application based policy decision (see draft-ohta-e2e-multihoming) site A to ISP L to ISP M L:A:hostM:A:host site exit router

IETF #57 in Viena6 Implementation of site-exit router selection (2/2) To reduce the impacts on routing mechanisms, we propose: Announce default routes to site-exit routers and intra-site routes only. –Full route is not needed Apply source address based routing only for default route entries. –Routing loop never occurs. –Modification to hosts, routers and routing protocol is needed but is minimum. site A to ISP L to ISP M L:A:hostM:A:host site exit router

IETF #57 in Viena7 Concluding Remarks Site-exit router selection using source address based routing –for end-to-end redundancy/load sharing with multiple paths Impacts on hosts, routers and routing protocols –Intra-site source address based routing is needed, but special treatment only for default routes is enough. Impacts on L4 or above –Some mechanism is needed for proper source address selection –Transport layer survivability would be supported by Socket API extension with LIN6 (draft-arifumi-lin6-multihome-api) Some extension of SCTP multihoming support (RFC3257)

IETF #57 in Viena8 Routing Model src: M:A:s, dst: M:B:tsrc: L:A:s, dst: N:B:t src: L:A:s, dst: M:B:t src: M:A:s, dst: N:B:t