University of California/Berkeley

Internet and IPv6

Reviews for EE290TMinghua Chen

minghua@eecs.berkeley.edu

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.

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

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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)

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Internet = Mail System

Berkeley Oakland Los Angeles

USA

Int.

New York

…

…

A mail system

Bottleneck

University of California/Berkeley

Internet = Mail System

Berkeley Oakland

Los Angeles

South CANorth CA

USA

Int.

… …

…

…

…A better mail

system

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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!!

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Address Run Out• 232 = 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 107 times

of the # of computers in DARPA time.

0

100000

200000

300000

400000

500000

600000

700000

800000

900000

1000000

1989

1991

1993

1995

1997

1999

2001

2003

2005

hosts

460 Million users

Source: Cerf, based on www.nw.com, Jan 2000Source: Cerf, based on www.nw.com, Jan 2000

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# Of Items In A BGP Routing Table

Moore’s Law and CIDRmade it work for a while

Projected routing table growth withoutCIDR

Deployment Period of CIDR

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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

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What Do IPv6 Do?

• Address– 128 bits. How large it is?

• ~ 3×1038

• Suppose earth as a smooth sphere, then there are one mol (6.02×1023) IPs/m2

– 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

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Difference In Header

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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

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

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 IPv6 node

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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?

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