Transcript PPT Version
6lowpan ND Optimization draft Update Samita Chakrabarti [email protected] Erik Nordmark [email protected] IETF 69, 2007 draft-chakrabarti-6lowpan-ipv6-nd-03.txt Document History The draft has been around since 2006 Several modifications based on wg comments Several presentations were made at the IETF working group meetings. Version 03 is the latest 6Lowpan IPv6 ND Background The solution handles prefix assignment and assumes one IPv6 router per 6lowpan network Main Goals for optimization Reduce or avoid DAD in 6lowpan network Minimize multicast messages in RA, RS, NS and reduce unneeded unicast messages (NUD) Captures basic 6lowpan network topologies and components based on interim wg comments Many optimizations in this solution are applicable to non-multicast or non-broadcast network in general Simple Star Topology rfd ffd P AN Coordinator rfd rfd rfd Assume IP link (~subnet) has one PAN coordinator Assume one 6lowpan is one PAN ID Assume the coordinator's unicast address is known from joining the PAN L2 Mesh Topology Support ffd P AN Coordinator ffd ffd ffd rfd rfd rfd ffd Coordina tor rfd Ms gs (RS ) routed by L2 layer Assume one PAN coordinator per 6lowpan link Assume each coordinator has a parent coordinator Allows a unicast-only path to PAN coordinator Can send packets to “allrouters” MC using this Recent Changes Added text on Security section The threat level of a 6lowpan IPv6 router is a bit higher because the end-nodes are battery powered. A need for authenticated RA and NA: IPv6 router is the central point for address resolution. Due to reduced processing power of the end-nodes, it is assumed that SEND protocol may not be directly applicable in 6lowpan ND. For example, RSA keys are too large for such small devices. Perhaps ECC instead of RSA algorithm. Senders of neighbor solicitations should use SEND nonce option to match the response. Limited 6lowpan ND security along with applied 802.15.4 level security may be sufficient in most situations Bootstrapping Information in this draft? Bootstrapping requirements Assignment of IPv6 prefix Finding out IPv6 router, co-ordinator’s L2 addresses Finding out 6lowpan service information? Any mechanism for access key and subsequent key derivation for secure ND and data transfer Anything else? Next Revision To Do: Handle short addresses ? Handling bootstrapping information? More investigation on secure 6lowpan ND ? Next Step Should this draft be published as a working group item ? Should this draft be written as a generic ND solution for non-broadcast and non-multicast network with an addendum for 6lowpan networks?