IPV6.

1. IPV6. .

2. Web, ftp, telnet, etc. application presentation session transport TCP, UDP network IPv4 link Ethernet physical What is IPv4? • Version 4 of the Internet Protocol • 30+ Years Old • Incredibly successful • Today’s Internet runs over IPv4 • IPv4 address : 32 bits • Many add-ons

3. IPv4: A Victim of Its Own Success • 1990 - IPv4 address • Class B address space exhausted by 1994 • All IPv4 address space exhausted between 2005 - 2011 • Internet routing tables suffering explosive growth • Internet routing today is inefficient • Running out of Internet addresses • Stops Internet growth for existing users • Prevents use of the Internet for new users

4. … a longer term solution IP next generation (IPng) • 1991: Work starts on next generation Internet protocols • More than 6 different proposals were developed • 1993: IETF forms IPng Directorate • To select the new protocol by consensus • 1995: IPv6 selected • Evolutionary (not revolutionary) step from IPv4 • 1998: IPv6 standardized • Today: Initial products and deployments

5. Web, ftp, telnet, etc. application presentation session transport TCP, UDP network IPv6 link Ethernet physical What is IPv6? • Version 6 of the Internet Protocol • Version 5 was allocated to the experimental Internet Stream Protocol (RFC 1190) • 5+ years old • IPv6 address : 128 bits

6. Major goals of IPV6 • Providing improved security. • This was made possible by introducing • Authentication Header and Encrypted Security Payload Header. • Reduction in the size of Routing Tables. • Providing for a single, unique address assignment to mobile hosts. • Providing support for new as well as older versions of the IP.

7. IPv6 Immediate Benefits • Increased Address Space • 128 bits • 2^128 is a really big number • Efficient addressing and routing topology • NAT is not required • Restores end-to-end IP addressing • And while we’re at it, we might as well make a few other improvements…

8. IPv4 Header (20 bytes) 0 31 16 Version Hd len Tot len ToS identification DF MF Fragment offset protocol TTL Hd chksum Source Address 20 bytes 32 bits Destination Address 32 bits Options (if any)

9. IP: Datagram format

10. IPv6 Header (40 bytes) Version Prio Flow Label Payload Length Next Header Hop Limit Source Address Destination Address 0 31 16 128 bits 40 bytes 128 bits

11. Note that while the IPV6 address are four times as large as the IPV4 address, the header length is onlytwice as big.

12. Notations of IPv6 Addresses • 128 bit is represented as: • 8 integers (16-bit) separated by colons • each integer is represented by 4 hex digits Example: FEDC:BA98:7654:3210:FEDC:BA98:7664:3210

13. bit 0 bit 0 8 16 24 4 12 16 24 31 Class Flow Label Ver. IHL TOS Total Length Ver. Payload Length Next Header Hop Limit Identifier Flags Fragment Offset TTL Protocol Header Checksum 32 bit Source Address 128 bit Source Address 32 bit Destination Address Options and Padding 128 bit Destination Address Removed Changed IPv6 Header – Comparison with IPv4 31 IPv4 Header 20 octets, 12 fields, including 3 flag bits + fixed max number of options IPv6 Header 40 octets, 8 fields + Unlimited Chained Extension (options) Header

14. IPv6 Header TCP Header Application Data Next = TCP IPv6 Header Fragment Hdr Security Hdr TCP Header Data Frag Next = Frag Next = Security Next = TCP IPv6 Extension Headers • IP options have been moved to a set of optional Extension Headers • Extension Headers are chained together

15. IPv6 Header Performance Wins Layout • Fixed Size IPv6 Header • Unlike IPv4 - Options not limited at 40 bytes • Fewer fields in basic header • faster processing of basic packets • Efficient option processing • Option fields processed only when present • Processing of most options limited .performed only at destination

16. IPv6 Header Performance Wins Processing • Remove checksum from Network Layer • Datalinks are more reliable these days • Upper Layer checksums are now mandatory (for example, TCP, UDP, ICMPv6) • No fragmentation in the network • Reduce load on routers • Easier to implement in hardware • Easy for Layer 3 switching of IP

17. The power of IPv6 Addressing Management Security and QoS

18. Simplifications • Skip leading zeros • Example:1080:0000:0000:0000:0008:0800:200C:417A • is reduced to: 1080:0:0:0:8:800:200C:417A • A set of consecutive nulls is replaced by :: (at most one :: inside an address) • the above address is reduced to: • 1080::8:800:200C:417A

19. Simplifications • Fixed format headers • no options -> no need for header length • options expressed as Extension headers • No header checksum • reduce cost of header processing, no checksum updates at each router • minimal risk as encapsulation of media access protocols (e.g..., Ethernet, PPP) have checksum

20. Renaming • Total Length Payload Length • not include header length • max length 64Kbytes with provision for larger packets using “jumbo gram” option • Protocol Type Next header, can be set to: • Protocol type (UDP,TCP, etc..) • Type of first extension header • TTL Hop limit • number of hops NOT number of seconds

21. New Fields • Flow label & Priority • to facilitate the handling of real time traffic

22. Options Extension Headers Routers treats packets with options as “second class citizens” because it is slow to process, thus programmers tend not use them and options almost became obsolete.

23. Daisy Chain of Headers TCP Header + Data IPv6 Header Next Header= TCP IPv6 Header Next Header= Routing Routing Header Next Header= TCP TCP Header + Data

24. IPv6 extension headers • Hop-by-hop options • Routing • Fragment • Destination options • Authentication • Encryption Security Payload

25. IPV6 overview and comparison with IPV4 .

26. IPv6 • IP v4 - current version • IP v5 - streams protocol • IP v6 - replacement for IP v4 • During development it was called IPng • Next Generation • 128 bits in length • Why Change IP? • Address space exhaustion • 232 different addresses gives over 4 billion addresses is not enough! • Due to growth of wireless, PDA, and Internet. • IP v 1-3 defined and replaced • Other enhancements

27. IPv6 • IP v 1-3 defined and replaced • IP v4 - current version • IP v6 - replacement for IP v4 • During development it was called IPng • Next Generation • 128 bits in length • Why Change IP? • Address space exhaustion • 232 different addresses gives over 4 billion addresses is not enough! • Due to growth of wireless, PDA, and Internet. • Other enhancements

28. IPv6 vs. IPv4 • The changes from IPv4 to IPv6 are primarily in: • expanded addressing capabilities; • header format simplification; The fixed size with a length of 40 octets. • flow labeling capability; • Support for resource allocation • improved support for extensions, options, and QoS; • Support for more authentication and security. • Supports unicast, anycast and multicast [First eight bits are all 1s]. • Embedded IPv4 address [First 80 bits of all 0s and next 16 are all 1s and then IPv4 address] OR [96 bits of 0s]. • Source node can assign priority which is used in priority routing. • Address autoconfiguration • Local scope model: No routers; simply MAC address is used. • Stateless server model: Request is send to well-known multicast address with MAC address and you get IPv6 address based on the knowledge of the network in reply. • Stateful server model: Mapping of MAC and IPv6 address is used.

29. IPv6 Format

30. Extension Headers

31. Extension Headers

33. Fragment Header • Routers do not fragment oversized packets • Sender is to fragment & Receiver is to reassemble Reserved Fragment offset Res M Next Header Identification

34. Hdr Ext Len Next Header Options Option Type Opt Data Len Option Data Destination Option Header Will only be examined by the station specified in the destination address.

35. Opt Len = 4 194 Jumbo Payload Length Hop-by-Hop Option Header Will be examined by each router. Has same form as destination options hdr. To satisfy networking requirement of supercomputers, the Jumbo payload option is used to send very large packets (the IPv6 length field is set to zero):

36. Headers • Authentication header Guarantee that the source address is authentic & the packet hasnot been altered during transmission. • Encryption header Guarantee that only legitimate receivers will be able to read the content of the packet

37. Points of Controversy • Do we need more than 255 Hops? • allowing hop count to be very large, looping packets will be relayed many times before being discarded • Should packets be larger than 64K? • allowing very large packets increase the size of queues and the variability of queuing delays • Can we live without checksum? • Some IPv4 routers started to cut corners by not verifying checksums to gain advantage over competition. By removing checksum altogether offers all routers the same advantage.

38. Real-time Support & Flows • A proper handling offlows is required for high-quality multimedia communications in the new Internet • A flowis a sequence of packets sent from a particular source to a particular (unicast or multicast) destination for which the source desires special handling by the intervening routers.

39. Security • If security is provided at the IP level it becomes standard service that all applications can use • It is absolutely necessary to implement if we want to develop of commercial usethe Internet, e.g...., to deter sniffing attacks on passwords and credit card numbers.

40. Quality of Service potential • Support for diffserv (Differentiated Service) • Class field enables a source to identify desired class of service / delivery priority of its packets • Correspond to Type-Of-Service in IPv4 • Support for Intserv (Integrated Service) • Enable a source to identify flows needing special QoS • Flow • a sequence of packets which need special handling • Not fully defined yet

41. Ipv6 address categories • Unicast: (One station sends a packet to another single station / interface.) • Multicast: (One station sends a packet to every member station / interface belonging to a designated group.) • Anycast: (A form of packet transfer in which the packet is delivered to the nearest member of a designated group instead of sending to each group member individually.) Often used for clusters.

42. . • Unlike IPv4 address notation, in which a 4- • part IP address was expressed in Decimal • Number System with a ‘.’ used as a separator • between every two parts; an IPv6 address is • expressed as an 8-part IP address expressed in • Hexadecimal Number System with a ‘:’ used • as a separator. • Example: • ABCD:CA74:120A:4567:BDEA:FA3B:BB4C:1963

43. . • IPv6 permits Address Abbreviation / Shorthand • Notation. • Examples: • ABCD:0000:120A:0000:0000:0000:BB4C:1963 can • be denoted as: ABCD:0:120A:0:0:0:BB4C:1963 • -- a case of replacing leading zeros by a single zero • Similarly, this address can be further abbreviated as: • ABCD:0:120A::BB4C:1963 • -- a case of eliminating an all-zero part of the address

44. Think IPv4/IPv6 Interoperability not Migration • Facts: • Millions of nodes are running IPv4 today • Some nodes will never upgrade to IPv6 • Large investment in IPv4 applications • Consequences: • IPv4 and IPv6 will coexist for an extended period • Hosts and routers can be upgraded to IPv6 independently • Transition must prevent isolation of IPv4 nodes

45. Mobile ipv6 • The purpose of Mobile IP is to enable a terminal to conduct uninterrupted communication with a single IP address wherever it goes or however it moves. • Such situation would arise if we use IP-based mobile phone (or have a voice conversation with PDA using Voice over IP) while driving a car. • If a node continue to move while connecting to IP network service, the node would have to change its IP address sooner or later. • That is because the node will have to connect to different network segment eventually. In IPv4, IP address is dynamically assigned by DHCP services normally. • In IPv6, change in network segment means a change in network prefix, the first half of the IPv6 address. • In either case, communication (voice conversation in the above example) must be terminated when IP address of the moving node gets changed. • In IP networking, nodes are identified with IP addresses. If a communicating node changes its IP address abruptly, it simply gets recognized as a different node. • Mobile IP solves this issue, and enables nodes to move from one network segment to another while maintain its communication by keeping the same IP address

46. Components of mobile node • mobile node A node that changes connecting network segments by its moves. A mobile node first acquires a “home address”, a dedicated IP address, at “its home network”. Home address is used as a tool to enable uninterrupted communications. The mobile node acquires new addresses at new locations. Such addresses are called care-of addresses. • home agentHome agent helps mobile nodes to appear to be using only one IP address, when in fact, they acquire new addresses and use them after moves. A home agent is placed on a home network. It receives communication packets from outside nodes to mobile nodes, and transfers these packets to their new addresses.

47. Components of mobile node • How does Mobile IPv6 work? A mobile node, as pointed out in the above, has its home address, but gets a new address, or care-of address, at a new location. Then the mobile node sends these two addresses to its home agent. This information is called “binding update”.Home agent maintains such binding update information for all mobile nodes under its control. When an outside node attempts to connect to one of the mobile nodes (with the home address of the mobile node as destination address of the packet), the home agent receives the packets in the place of the mobile node. Then, based on the home address/care-of address table, the home agent finds the current care-of address of the mobile node. The home agent encapsulates the packets from outside nodes and sends them to the mobile nodes

48. . • When the mobile node wants to send packets to an outside node ,it encapsulates packets with its home address as source address and outside node address as destination address in packets destined to the home agent • The home agent receives these packets ,encapsulates them and sends the original packets to the outside node • The above procedures enable continuous communication in both directions • Thus all communications need to go through the home agent

49. Mobile IPv6 • Route Optimization is built as a fundamental part of Mobile IPv6 unlike Mobile IPv4 where it is an optional set of extensions that may not be supported by all nodes. • Foreign Agents are not needed in Mobile IPv6. The enhanced features of IPv6 like Neighbor Discovery and Address Autoconfiguration enable mobile nodes to function in any location without the services of any special router in that location.