1. University of California/Berkeley Internet and IPv6 Reviews for EE290T Minghua Chen minghua@eecs.berkeley.edu

2. University of California/Berkeley Outline Internet – “The Internet: a tutorial”, by J. Crowcroft IPv6 – “The next generation of the Internet: aspects of the Internet protocol version 6”, by C. Lee et al.

3. University of California/Berkeley Internet – A Success Underlying technique –IP – addressing and routing –TCP/UDP – data transmission control (e.g., error recovery, flow control) Application –WWW (killer application) –E-mail –Telnet –Chat

4. University of California/Berkeley Internet – A Success Underlying design –Connectionless datagram switching –Stateless end-to-end principle –Best effort –Client server model Less assumptions  more scalable & robust  easy to develop –Cost: some performance loss (e.g. transmit data over a network whose MTU >> 576 bytes – maximum packet size in IPv4)

5. University of California/Berkeley Internet = Mail System BerkeleyOaklandLos Angeles USA Int. New York … … A mail system Bottleneck

6. University of California/Berkeley Internet = Mail System BerkeleyOakland Los Angeles South CANorth CA USA Int. … … … … … A better mail system

7. University of California/Berkeley Problems in IPv4 Scalability –Address run out –Explosive routing tables (router is the bottle neck of Internet, instead of network speed) QoS –Best effort is not enough –Commercialized Internet Security The most urgent thing!!

8. University of California/Berkeley Address Run Out 2 32 = 4,294,967,296, will run out before 2005 “32 bits should be enough address space for Internet” – Vint Cerf, 1977 –32 bit address space is approximately 10 7 times of the # of computers in DARPA time. 460 Million users Source: Cerf, based on www.nw.com, Jan 2000

9. University of California/Berkeley # Of Items In A BGP Routing Table Moore’s Law and CIDR made it work for a while Projected routing table growth without CIDR Deployment Period of CIDR

10. University of California/Berkeley Effort On Saving IPv4 VLSM(Variable Length Subnet Mask) –Try to figure out “problem of triple bears” CIDR(Classless Inter-Domain Routing) NAT(Net Address Translation) L3 Switching ， MPLS RSVP 、 RTP/RTCP 、 DirectRoute 、 SSL However, due to scalability reason, a new IP protocol has to be developed

11. University of California/Berkeley What Do IPv6 Do? Address –128 bits. How large it is? ~ 3×10 38 Suppose earth as a smooth sphere, then there are one mol (6.02×10 23 ) IPs/m 2 –Why 128 bits? –Unicast, multicast, anycast –For one interface, it can have multiple IPv6 addresses Routing –Prefix routing and aggregation (based on CIDR) –Address space is strictly aggregated –Fixed size based header

12. University of California/Berkeley Difference In Header

13. University of California/Berkeley What Do IPv6 Do? MTU: 576 bytes  1280 bytes Type of Class (8 bits) and Flow label (20 bits) fields in header Mobile IP –Redirect the route to the mobile node if needed Security architecture –Protection for key header

14. University of California/Berkeley What Do IPv6 Do? Network management –Neighbor discovery MTU Address resolution Network prefix Address lifetimes –Address autoconfiguration Use 64-bit IEEE EUI-64 address of the hardware Network prefix + 64-bit hardware address

15. University of California/Berkeley IPv4  IPv6 Won’t happen in one day Dual protocol stacks Currently, 6bone uses IPv6 over IPv4 tunnel to connect IPv6 nodes IPv4 world IPv6 node

16. University of California/Berkeley Discussions IPv6 changes the underlying technique of Internet, then what will be the change in application? What will be the killer application in future? In past, we have IPv4, then apps comes out; how about today’s situation?

17. University of California/Berkeley Summary Internet is a success IPv4 has problems, especially in address space, routing, QoS and security IPv6 want to address those problems It may be a long time for IPv4 migrating to IPv6