1. 1IETF57 MANET WG Ad Hoc IP Address Autoconfiguration Jaehoon Paul Jeong ETRI paul@etri.re.kr http://www.adhoc.6ants.net/~paul/ 16 th July 2003 57th IETF – Vienna, Austria draft-jeong-adhoc-ip-addr-autoconf-00.txt

2. 2IETF57 MANET WG Motivation of the Draft 4 basic MANET unicast routing protocols will be published as experimental RFC soon. –AODV, DSR, OLSR and TBRPF Next step? –Addressing is as essential as Routing Automatic IP address configuration is necessary in MANET, which has dynamic topology. –Various approaches have been suggested in research domain Stateless vs. Stateful approaches Strong DAD vs. Weak DAD Active DAD vs. Passive DAD Therefore, it is time to develop MANET IP Address Autoconfiguration in engineering mode.

3. 3IETF57 MANET WG Framework of the Draft 1.IP Address Generation 2.Duplicate Address Detection -Hybid scheme considering MANET partition Strong DAD Weak DAD 3. Maintenance of Upper-layer Sessions

4. 4IETF57 MANET WG IP Address Generation Selection of Random IP Address –IPv4 IPV4_MANET_PREFIX + 16-bit Random Number –169.254/16 is used as IPV4_MANET_PREFIX. –IPv6 IPV6_MANET_PREFIX + 64-bit Random Number –fec0:0:0:ffff::/64 is used as IPV6_MANET_PREFIX. »Because of the deprecation of IPv6 site-local address, a new local prefix for local networks separated from the Internet is necessary.

5. 5IETF57 MANET WG Duplicate Address Detection Phase 1 : Strong DAD –Time-based DAD For detecting IP address duplication in a connected MANET partition within a finite bounded time interval –Strong DAD is performed during the initiation of nodes network interface. Phase 2 : Weak DAD –Routing-based DAD For detecting IP address duplication during ad hoc routing It can handle the address duplication by MANET partition and mergence. Key is used for the purpose of detecting duplicate IP addresses. –Virtual IP Address = IP Address + Key

6. 6IETF57 MANET WG Process of Duplicate Address during Weak DAD Each node investigates the virtual IP address contained in ad hoc routing control packet –to see if there is the same address with different key in routing table or cache. If there is the duplicate IP address, –The node sends an AERR (Address Error) message to another node using duplicate address that is associated with a different key. The node, receiving the AERR message, auto- configures a new IP address –through Strong DAD

7. 7IETF57 MANET WG Maintenance of Upper-layer Sessions Consequence of Address Replacement –When address duplication happens and the duplicate address is replaced with another, the sessions above network layer can be broken. There should be a mechanism to guarantee the survivability of upper-layer sessions –Announcement of address change to peer-nodes is needed. It is performed through AERR message.

8. 8IETF57 MANET WG Data Delivery after resolving Address Duplication Data Delivery through IP Tunneling –After receiving the AERR message, the peer node sends its data packets to the node, having announced address change, through IP tunneling. Peer Node Address : IP pn Announced Node New Address : IP new Old Address : IP old Data Packet SRC Addr : IP pn DEST Addr : IP new SRC Addr : IP pn DEST Addr : IP old Payload Outer IP Header Inner IP Header

9. 9IETF57 MANET WG Discussion This draft can include Passive DAD (PDAD). –PDAD does not need key unlike Weak DAD It is the work of Kilian Weniger. How about MANET wg draft? –In order to develop a MANET IP Address Autoconfiguration Any questions or comments?