TDC /202, Winter Unit 1: Introduction. From IPv4 to IPv6 Introduction: –Internet Evolution –The need for high-speed, high-capacity networks with quality-of- service (QoS) guarantees –Protocol and implementation: a simple example IPv6 –Goals –Main Features –Main Header –Address Formats and Notation –Extension Header –Transition from IPv4 to IPv6 Dual stack Header translation Tunneling –Configured –Automatic

TDC /202, Winter Introduction: Internet Evolution YearEvent 1966APRA packet-switching experimentation 1969First ARPANET nodes operational 1972Distributed invented 1973First non-U.S. computer linked to ARPANET 1975ARPAET transitioned to Defense Communications Agency 1980TCP/IP experimentation begins 1981New host added every 20 days 1983TCP/IP switchover complete 1986NSFnet backbone created 1990ARPANET retired 1991Gopher introduced 1991WWW invented 1991PGP (Pretty Good Privacy) released 1992Mosaic introduced 1995Internet backbone privatized 1996OC-3 (155 Mbps) backbone built 1998Number of registered domain names exceeds 2 million 2000Number of indexable web pages exceeds 1 billion

TDC /202, Winter

TDC /202, Winter The need for high-speed, high-capacity networks with quality-of-service (QoS) guarantees Availability of Web-based applications that are palatable to the end user Increase in traffic volume generated by users Increased speed and efficiency of networks and the Internet Emergence of High-Speed LANs Corporate Wide Area Networking needs: from centralized to network-centric Digital electronics: DVD, digital cameras etc.

TDC /202, Winter QoS on the Internet

TDC /202, Winter To provide QoS Two emerging changes to the internet architecture ISA (Integrated Services Architecture) Differentiating Services (DS) Involve upgrading router hardware and involve a number of new protocols IPv6: it provides features that are useful to ISA and DS RSVP: The Resource ReServation Protocol – Key element of ISA RTP: The Real-Time Transport Protocol Multicast routing protocols

TDC /202, Winter Network Protocols = agreed-upon ways in which computers exchange information  Syntax: structure or format of the data  Semantics: meanings  Timing: when data should be sent and how fast it can be sent. A simple example protocol and its implementation: SLIP

TDC /202, Winter SLIP (Serial Line IP): RFC 1055  Character-oriented  END IP-packet END …  Character stuffing The following C language function sends SLIP packets. They depend on two functions, send_char() and recv_char(), which send and receive a single character over the serial line. /* SLIP special character codes */ #define END 0300 /* indicates end of packet */ #define ESC 0333 /* indicates byte stuffing */ #define ESC_END 0334 /* ESC ESC_END means END data byte */ #define ESC_ESC 0335 /* ESC ESC_ESC means ESC data byte */

TDC /202, Winter /* for each byte in the packet, send the appropriate character * sequence */ while(len--) { switch(*p) { /* if it's the same code as an END character, we send a * special two character code so as not to make the * receiver think we sent an END */ case END: send_char(ESC); send_char(ESC_END); break; /* if it's the same code as an ESC character, * we send a special two character code so as not * to make the receiver think we sent an ESC */ case ESC: send_char(ESC); send_char(ESC_ESC); break; /* otherwise, we just send the character */ default: send_char(*p); } p++; } /* tell the receiver that we're done sending the packet */ send_char(END); }

TDC /202, Winter IPv6 (IPng) (1990: IETF starts to work on a new protocol. RFC call for proposals for discussion. Listed goals) Goals: 1. Support billions of hosts, even with inefficient address space allocation. 2. Reduce the size of the routing tables. 3. Simplify the protocol, to allow routers to process packets faster. 4. Provide better security than current IP. 5. Pay more attention to type of service, particularly for real-time data. 6. Aid multicasting by allowing scopes to be specified. 7. Make it possible for a host to roam without changing its address. 8. Allow the protocol to evolve in the future. 9. Permit the old and the new protocols to coexist for years. Main Features:  128-bit address.  Simplification of header: 7 fields vs 13 in IPv4.  Better support for options.  Big advance in security: authentication and privacy.  More attention to type of service.

TDC /202, Winter Figure 25-1 IPv6 address Figure 25-2 Abbreviated address

TDC /202, Winter Figure 25-3 Abbreviated address with consecutive zeros Figure 25-4 Partial address FDEF::BBFF/96 actually expands into FDEF:0:0:0:0:0:0:BBFF/96 = FDEF:0:0:0:0:0 FDEC:0:0:0:0:BBFF::/96 or FDEC::BBFF:0:0/96

TDC /202, Winter Figure 25-5 Address Structure

TDC /202, Winter Figure 25-6 Provider-based address Figure 25-7 Address hierarchy

TDC /202, Winter Figure 25-8 Unspecified address: as a source address only when a host does not know its own address Figure 25-9 Loopback address

TDC /202, Winter Figure Mapped address: Migrated to IPv6 but still want to use IPv4 Figure Compatible address: IPv4 only

TDC /202, Winter Figure Link Local Address – like private address not to be used on the Internet Local Addresses Figure Site local address: private addresses for a network with several subnetworks not connected to the Internet Figure Multicast address

TDC /202, Winter Figure IPv6 Datagram Figure IPv6 datagram format

TDC /202, Winter Figure Extension Header format

TDC /202, Winter Figure Hop-by-hop option header format

TDC /202, Winter The format of options in a hop-by-hop option header Jumbo payload

TDC /202, Winter Extension header for routing

TDC /202, Winter Extension header for routing (source routing)

TDC /202, Winter In IPv6 minimum MTU = 576 bytes only source can fragment. Use Path MTU Discovery technique to find the smallest MTU or use 576. Fragmentation Header Authentication Header Validate the message sender Ensures integrity of data (data not altered. Security parameter index  what algorithm to use Encrypted Security Payload (ESP)

TDC /202, Winter Transport-Mode Encryption Tunnel-Mode Encryption e.g.TCP segment or UDP datagram

TDC /202, Winter Transport mode vs tunnel mode (Usually host to host) (Usually between security devices such as firewalls and gateways)

TDC /202, Winter Transition from IPv4 to IPv6: Strategies Dual-stack operation An IPv6 nodes run both IPv6 and IPv4 and use the Version field to decide which stack should process an arriving packet. Initially all hosts should have a dual stack before migrating completely.

TDC /202, Winter Header Translation When a majority of the Internet has migrated to IPv6

TDC /202, Winter Tunneling: when IPv6 packets must travel through an IPv4 region Tunneling (Configured)

TDC /202, Winter Tunneling (Automatic)

TDC /202, Winter Key to abbreviations Sending rules for an IPv6/IPv4 node