SDI Seminar

Speaker: Dave Johnson,CMU

Mobility Support in IPv6

Date: February 6, 1997


IP version 6 (IPv6) is being designed within the Internet Engineering Task Force (IETF) as a replacement for the current version of IP used in the Internet today (IPv4). Without specific support for mobility in IPv6, packets destined to a mobile node would not be able to reach it while the mobile node is away from its home IP subnet, since as in IPv4, routing is based on the network prefix in a packet's destination IP address. In order to continue communication in spite of its movement, a mobile node could change its IP address each time it moves to a new IP subnet, but the mobile node would then not be able to maintain transport and higher-layer connections when it changes location. Efficient mobility support in IPv6 is particularly important, since mobile computers are likely to account for a majority or at least a substantial fraction of the population of the Internet during the lifetime of IPv6.

IPv6 is derived from IPv4 and is in many ways similar to it. As such, the current IETF Mobile IP protocol for IPv4 could be adapted for use in IPv6, with only the straightforward changes needed to accommodate the differences between IPv4 and IPv6 such as the size of addresses. However, the development of IPv6 presents a rare opportunity, in that there is no existing installed base of IPv6 hosts or routers with which we must be compatible, and the design of IPv6 may still be modified to account for the few special needs of mobile nodes. In this talk, I will describe the protocol we have designed for Mobile IP for IPv6, and will give a status report on its current progress toward approval as an Internet standard.