The Future of TCP/IP

1. The Future of TCP/IP • Always evolving: • New computer and communication technologies • More powerful PCs, portables, PDAs • ATM, packet-radio, fiber optic, satellite, cable • New applications • WWW, electronic commerce, internet broadcasting, chat • Increased size and load • New policies • New industries, new countries • Move away from centralized core architecture

2. The Future of IP • IP version 4 (IPv4) has been in use since the 1970’s • IPv4 is being replaced: • Address space exhaustion • Running out of 32-bit IP addresses • Support new applications • Electronic commerce - authentication • Audio/video - Quality of Service (QoS) guarantees • Decentralization

3. The Next Version of IP • Work on an open standard has been underway for years • Add functionality to IPv4 • Modify OSI CLNS • Simple IP Plus (SIPP) - simple extensions to IPv4 • IP - The Next Generation (Ipng) • IPv6

4. IPv6 • Details available at: http://playground.sun.com/pub/ipng/html/ipng-main.html • Major similarities with IPv4: • Connectionless datagram delivery • TTL, IP options, fragmentation • Major differences from IPv4: • Larger address space • 128-bit IPv6 IP addresses • New datagram format

5. VERS (4) HLEN SERVICE TYPE TOTAL LENGTH IDENTIFICATION FLAGS FRAGMENT OFFSET TIME TO LIVE PROTOCOLHEADER CHECKSUM SOURCE IP ADDRESS DESTINATION IP ADDRESS IP OPTIONS (IF ANY) PADDING DATA VERS (6) TRAFFIC CLASS FLOW LABEL PAYLOAD LENGTH NEXT HEADER HOP LIMIT SOURCE IP ADDRESS DESTINATION IP ADDRESS IPv6 (cont) • IPv4 - fixed-size header, variable-length options field, variable length data field: • IPv6 - a set of variable-length (optional) headers:

6. BASE EXTENSION …. EXTENSION DATA HEADER HEADER 1 HEADER N IPv6 Extension Headers • IPv6 datagram format: • Fixed-size base header • Zero or more variable-length extension headers • Variable-length data (or payload)segment

7. IPv6 Extension Headers (cont) • Zero extension headers • One Extension header • Two extension headers Base Header Next=TCP TCP Segment Base Header Next=Route Route Header Next=TCP TCP Segment Base Header Next=Route Route Header Next=Auth Auth Header Next=TCP TCP Segment

8. Security in IPv6 • Based on two mechanisms: • Authentication Header (AH) • Proof of the sender’s identity • Protection of the integrity of the data • Encapsulating Security Payload (ESP) • Protection of the confidentiality of the data

9. Base Header Next=Auth Auth Header Next=TCP TCP Segment Authentication Header - Example

10. Authentication Header • Security parameters index field – specifies which specific authentication scheme is being used • Authentication data field – contains data that can be used to establish the datagrams: • Authenticity • Integrity

11. Encapsulating Security Payload • Encryption of the datagram or part of the datagram • 2 modes: • Transport mode – encryption of datagram payload • Tunneling mode • Encryption of entire datagram • Encapsulation of datagram

12. ESP Trailer Security Parameter Index Sequence Number Padding Pad Len Next Header ESP Auth Data (Var) ESP Transport Mode • Encryption of payload for privacy: Base Header Next=ESP ESP Header Next=TCP Encrypted TCP Segment

13. Base Header Next=ESP ESP Header Next=IP Encrypted Datagram ESP Tunnel Mode • Encryption of entire datagram for privacy

14. AH and ESP • Protect authenticity, integrity, and privacy:

15. IPv6 (cont) • Major differences from IPv4: • Improved Options • More flexibility and new options • Support for resource allocation • Packets labeled as belonging to particular traffic flow • Sender requests special handling (e.g. Qos, real-time, etc.) • Authentication, data integrity, and data confidentiality supported • Provision for protocol extension

16. IPv6 Fragmentation • IPv4 • Intermediate router fragments datagram when necessary • Ultimate destination reassembles • IPv6 - end-to-end fragmentation • Before sending a datagram, source must determine the path’s MTU • Source fragments the datagram • Ultimate destination reassembles

17. IPv6 Fragmentation (cont) • End-to-end fragmentation • Advantages • Disadvantages

18. Representing IPv6 Addresses • 128-bits • Binary: 00000000 00000001 10000010 00000011 11111111 11000101 00001110 00000000 00001000 01111111 00110000 10000011 00000000 00000000 00000000 00000000 • Dotted decimal: 0.1.130.3.255.197.14.0.8.127.48.131.0.0.0.0 • Hex-colon: 1:8203:FFC5:E00:807F:3083:0:0

19. Representing IPv6 Addresses (cont) • 128-bits • Compressed hex-colon format • Zero compression • A string of repeated zeroes is replaced by a pair of colons • Performed at most once per address (unambiguous) • Examples: • FF05:0:0:0:0:0:0:B3 = FF05::B3 • 0:0:0:0:0:0:E00:807F = ::E00:807F • 0:0:0:F6AD:0:0:0:0 = 0:0:0:F6AD::

20. 0 8 16 24 31 0 8 16 24 31 0 8 16 24 31 IPv4 Addresses Assignment • Class A • Class B • Class C 0 netid hostid 1 0 netid hostid 1 1 0 netid hostid

21. IPv6 Address Assignment Binary Prefix Type of Address Part of Address Space 0000 0000 Reserved (IPv4 compatible) 1/256 0000 0001 Reserved 1/256 0000 001 NSAP Addresses 1/128 0000 010 IPX Addresses 1/128 0000 011 Reserved 1/128 …. 0000 111 Reserved 1/128 0001 Reserved 1/16 001 Reserved 1/8 010 Provider-assigned unicast 1/8 011 Reserved 1/8 100 Reserved for geographic 1/8 101 Reserved 1/8 110 Reserved 1/8 1110 Reserved 1/16 1111 0 Reserved 1/32 1111 10 Reserved 1/64 1111 110 Reserved 1/128 1111 1110 Available for local use 1/256 1111 1111 Multicast 1/256

22. IPv6 Address Types • Unicast • Specifies a single computer • Cluster/Anycast • Specifies a set of computers that share an address prefix (possibly at multiple locations) • Multicast • Specifies a set of computers (possibly at multiple locations)

23. 010 Provider ID Subscriber ID Subnet ID Node ID IPv6 Address Hierarchy Address type prefix Provider prefix Subscriber prefix Subnet prefix IPv6 address