Auto Configuration and Mobility Options in IPv6 By: Hitu Malhotra and Sue Scheckermann

Why change from IPv4 to IPv6? w Need more addresses: 128-bit address space (4 times wider in bits than IPv4's 32-bit address space). w Consideration to Realtimeness: Flowlabel mechanism w Security w User friendly - “Plug and Play”

User Friendliness w “PLUG AND PLAY” literally to plug a node into an IPv6 network and have it configure to the network without human interference w Autoconfiguration implementation of the “plug and play”

Autoconfiguration w STATEFUL: A server must maintain status information about each node and administer that stored data w STATELESS: Mechanism allowing individual nodes to figure out what their IP configuration should be without a query to a server that has information about each node

Dynamic Host Configuration Protocol w DHCP Example of stateful autoconfiguration. A client/server protocol where the client queries servers for configuration parameters. w Problems administration of the list of IP’s a server to keep track of addresses in use

DHCPv6 w Combination of stateful and stateless autoconfiguration. w Solves the two problems in DCHP using two IPv6 capabilities: Hosts may build a “link local address”. Availability of a multicast.

IPv6 Stateless Autoconfiguration w Steps taken by nodes: Figures out own Link-Local Address Verify Link-Local address to be unique Determine what information is necessary for configuration IP address and/or other configuration info Determine where to get that information Uses stateless or stateful to get information

Router Advertisements w Next phase of autoconfiguration. w Routers advertise their availablity, various link and Internet parameters for configuration. w Two Flags indicate the type of autoconfiguration a node should use.

Mobile Networking w Goals: To allow IPv6 nodes to move from one IP subnet to another Packets destined to a mobile node will reach when away from home subnet

Micro to Macro Mobility w Micro-mobility communicating from cell to cell (wireless phones) w Macro-mobility movements of nodes from one network to another

Home Network w A permanent address is assigned to mobile node uses this home address like a permanent node when connected to home network w Home Agent a router that maintains a record of current “binding” of mobile node and “tunnels” packets to “care-of address”

Home Agent w Binding record of mobile node’s care-of address and remaining lifetime of that association w Tunneling path of packet while encapsulated (from home agent to care-of address) w Care-of Address assigned by foreign network or agent

Foreign Network w Mobile node listens for availability agent advertisement w Mobile node attaches itself to Foreign Network Assigns a care-of address to mobile node may use DHCP to get one OR specifies a Foreign Agent Uses the same inbound address for all foreign nodes and distributes the packets w Sends a message to Home Agent

Routing to a mobile node HOST Home Agent Foreign Agent Mobile Node Tunnel

How is this different from IPv4? w Security all packets must be authenticated w Routing IPv4 routing based on network prefix IPv6 Routing Header - loose source route

Resources w RFC’s request for comments 2462, 2002 w IPv6 Clearly Explained by Pete Loshin