CPE 426 Computer Networks

1
CPE 426 Computer Networks

• Week 6
• Chapter 24 IPv6

2
TOPICS

• Chapter 24 IPv6
• Motivation
• Features
• Header Format
• Addressing

3
Chapter 2424.3 IPv6 Motivation

• IP Protocol ?????????????????????
  ???????????????????????????????? Hardware ???
  Software ?????????????? IP Address ???? 32 ???
  ?????
• ??????????????????????????? ????????? CIDR ????
  NAT ???????????????????????????
• ????????????? ???????????????? Best Effort
  ???????????????? Application ????????????????
  ??????? Real-Time Service
• ??????????????????? IP ???????????????????
  ?????????????????? Routing ??? Addressing
  ???????????????????????????????? Replicate
  Service ???? Collaboration Group

4
Chapter 24 24.4 Difficulties

• IP version ???????????????? 1993
  ??????????????????????????????????????????????
  ??? Version ????????????????????????????
• ????????? IP ??????????????????????????????
  ??????? ??? Router
• ??????????? ???????????????? Version ????
  ?????????????? Network
• ????????????????????????? Application ????????

5
Chapter 24 24.5 Name and Version Number

• IP Version ???? ???????????????? IP The Next
  Generation
• ?????????? IPng
• ?????? Version ??? Version 6 ?????????????
  Version 5 ???????????????????(???? Experiment
  Protocol)
• ??????? IP ???????????????????????????? IPv6

6
Chapter 24 24.6 IPv6 Features

• IPv6 ?????????????????????? IPv4
  ??????????????????????????????????????
• ????????? Datagram(Connectionless)
• ?????? Datagram ??????? Route ????????????????
• ????????????????????????? Hop ??????
• ????????????????? IPv4 ?????????????
  ??????????????????????????????
• Header ????????????? ?????????????????????????????
  ?? Header ?????(Extension) ????????????
• ?????? IPv4 ?????????????? Header ?????????
  Header ????(Option) ???????????? Header ?????????

7
Chapter 24 24.6 IPv6 Features

• ?????????????????? IPv6 ?????????????
• Address Size
• ???????? 32 ??? ???? 128 ???
• Header Format
• ?????????????????????? ??? Field ???????????????
  (?????????????????)
• Extension Header
• ?????????????? IPv6 ?????????? Header
  ???????????? ?????? Datagram ???????????? Base
  Header ??????? Extension Header (?????)
  ?????????????
• Support for Real-Time Traffic
• ??????????????????????????????????????????????????
  ??? (????? QoS)
• Extensible Protocol
• IPv6 ???????????????????????????? Datagram
  ???????????? ??????????????????????????????

8
Ch. 24 24.7 IPv6 Datagram Format

• IPv6 Datagram ?????????? Header ??????????????
  ???????? Base Header ??????? ???????????????????
  Extension Header
• Base Header ?????????????
• Extension Header ?????????????????? Extension

9
Ch. 24 24.8 IPv6 Base Header Format

• ?????? 40 Octet(10 32-Bit Words)
• ?????????? IPv4
• ????? Field ????????
• Vers 4 bit ??????? 0x0110
• Traffic Class ???????????? Traffic ??????
  ?????????????? Differentiated Service
• ????????????????????????????????? Network
  ???????????????????????????? ???? Interactive
  Traffic, Real-Time Traffic ???????
  ???????????????????????
• Payload Length ??????????????? Payload ?????????
  IPv4 ?????????????????????????????? ?????????????
• Time-to-Live ????? Hop Limit
• Flow Label ????????????????????????????? Network
  ????? Virtual Circuit ????????????????
• IP Address ???????????????????? 128 ???
• Next Header ???????? Extension Header
  ????????????? ??????????????????????
  Data(Payload) ???????????? (???????????)

10
Ch. 24 24.8 IPv6 Base Header Format
11
Ch. 24 24.9 Implicit and Explicit Header Size

• ??????? Extension Header ?????????????????????
  ??????????????????? ????????????????????????????
  Extension Header ?????????????? Payload
  ?????????????????? Header
• ???? Implicit Header Size
• ??? Extension Header ?????????????????????????
  ??????? Header ???????????????????????????????????
  ?????????????
• ????? Explicit Header Size

12
Ch. 24 24.10 Fragmentation, Reassembly and Path
MTU

• ????? Fragmentation ??? IPv6 ?????????? IPv4
  ???????? Copy ???? Header ????????
  ?????????????????????????? Payload ???????
  Fragment
• ??? Base Header ????? Field ??? Fragment Offset
  ??? Flag ???????????????? Fragment ???????
  Fragment ???????????? Extension Header
  ??????????????
• ?????????? IPv4 ???????? Fragment ?????????????
  Router ??? Host ????????????? Fragment
• ??? Fragment ?????????????? MTU ??? Network ???
  Router ?????? Fragment ???? ?????? ICMP
  ???????????????
• ???????????????? Fragment ??

13
Ch. 24 24.10 Fragmentation, Reassembly and Path
MTU
14
Ch. 24 24.10 Fragmentation, Reassembly and Path
MTU

• ??? Fragment ?????????????? MTU ??? Network ???
  Router ?????? Fragment ???? ?????? ICMP
  ???????????????
• ???????????????? Fragment ?? ????? Router ???????
• Host ???????????????????????????????? Fragment
  ??????????
• Host ??????????????????????? MTU ???????? Network
  ??? Datagram ???????? ???????????? Fragment
  ????????????? MTU ??????
• ??????????? Path MTU
• ???????????? Iterative Process ???? Path MTU
  Discovery
• ???????????????? Fragment ????????????????
  ????????????? Error

15
Ch. 24 24.11 ????????????? Multiple Header

• ?????????????????
• Economy
• ??? Partition ????????? Header ???????????????????
  ?????????????? ????????????????????????????
  ????????? Fragmentation ?? IPv4 ?????? Datagram
  ???????????? Fragmentation ?????????????????
  Field ????????????????????????????? ?????? IPv6
  ????????????? Fragment ?????????????? Fragment
  Extension Header
• Extensibility
• ?????????????? Feature ??? IPv6 ????????????
  ???????????? Feature ?????????????????????
  Extension Header ???????? Extension Header
  ?????????????? ???????? Protocol ??????????????
  ?????????????
• ???????????????????????????????????????????
  Protocol ???????????????????????????????????
  Network ????????? Extension Header
  ???????????????????? Routing Header

16
Ch. 24 24.12 IPv6 Addressing

• ???????? IPv4 ?????????????????? Address ???????
  Network Connection
• ????????????? Address ???? Prefix ??? Suffix
  ???????
• ???????????????????????? Address ????????? IPv4
• ??? CIDR ??? Prefix ???????????????????
• ?????????? Prefix ?????????????????????????????
  (Hierarchy)
• IPv6 ????? Special Address ?????????? IPv4
• ????? Special Address ??????????? Broadcasting
  ??????? Network (?????????? Multicast ???)
• ?????????? Anycast Address ??????
• ????????????????????? Cluster Addressing
• ????????????????????? Copy ????????????????
  Anycast Group
• ??????? Multicast ???????????????????????? Group
• ????????????? Replicate Service

17
Ch. 24 24.12 IPv6 Addressing
18
Ch. 24 24.13 IPv6 Colon Hexadecimal Notation

• ?????? Dotted Decimal Notation ?????? 128 ???
  ???????????
• 105.220.136.100.255.255.255.255.0.0.18.128.140.10.
  255.255
• ??????????????? IPv6 Address ??????????? 16
  ??????? 16 ??? ???????? Colon
• Colon Hexadecimal Notation
• 69DC 8864 FFFF FFFF 0 1280 8C0A FFFF

19
Ch. 24 24.13 IPv6 Colon Hexadecimal Notation

• ???????? IPv6 Address ??????????? 16 ??????? 16
  ??? ???????? Colon
• Colon Hexadecimal Notation
• ???????????????????????????????????????
  ????????????????
• 69DC 8864 FFFF FFFF 0 1280 8C0A
  FFFF
• ??????????????????????????????? ???????? Zero
  Compression ???
• ???????????????? ?????????? Colon(?????????????)
• ???? FF0C000000B1 ? FF0C B1
• Zero Compression ????????????????????
• IPv6 Address ????????????????? 96 ??? ???Address
  ??? Transition ??? IPv4 Protocol
• ??? Transition ??? IPv4 ? IPv6 ???????????
  ???????????????? Protocol ???????????????????????
  ?????????? Transition ?????????
• ????????????????????????

20
Unicast Address Type

• Global Unicast Address
• Static Address, Stateless Autoconfiguration, DHCP
  Assigned
• Tunneled Address
• Others
• Link Local Address (FE80/10)
• Unique Local Address(FC00/7)
• Loopback (1)
• Unspecified ()

21
Link Local Address

• ??? IPv6 Network Interface ???? Link Local
  Address
• ???? Address ???????????????????????? Local
  Subnet
• ???????? Auto-configuration ????? FE80/64
  (?????? Address ??????????? FE80,FE90,FEA0 ???
  FEB0, ???????? FE80/10)???????? Mac Address
  ??????????????? EUI-64 (????????????)
• ????????????????????????????????? Interface
  ???????????????? Scope-ID

22
Global IPv6 Address

• Prefix 2000/3 ?????????????? 001
• ???????? 45 ?????????? Global Routing Prefix
  (IANA?RIR?ISP)
• ???????? 16 ???????? Subnet ID
• 64 ????????????? Interface ID ?????????? Host ??
  Subnet (Host ID ????? 64 ???)
• Global Routing Information ?????????? 64 ???
  Prefix ?????????????? (???????????????????????
  /127)

23
Global Address

• ICANN ????????? IP Address ?????? Regional
  Internet Registry(RIR) ???? Prefix /12 (2000/12
  ??? 200FFFFFFFFFFFFF/64)
• ????? ISP ???????? /32 ????????????? /48
  ??????????? Site
• ????? Site ????????? /64 ??????????? LAN
• ????? LAN ??????? 264 Interface

24
(No Transcript)
25
Multicast Address

• ??? Prefix FF00/8
• ???????? Scope ???????? Multicast ?????????????
  ??????????????? Bit ?? Multicast Group
• Link Local, Site, Global Scope
• ??? MLD (Multicast Listener Discovery) ?????????
  IGMP ?? IPv4

26
IPv6 ?? LAN

• ???????? Automatic Configuration
• ??? ICMPv6 ?? Message ????????????? Multicast
• ???????? Stateless Address Autoconfiguration
  ?????? DHCP
• Host ??????????? Address ???????????
• ??? Stateful ??? DHCP6

27
Stateless Address Auto-configuration

• ?????? Router Advertisement ????????????? Prefix
  / 64 ??? Subnet ????????
• ????????? Prefix ?????? ?????? Interface Address
  ?????? MAC Address ????? EUI-64

28
(No Transcript)
29
Example
30
Transition Mechanism

• Dual Stack Implementation
• Run ???? IPv4 ??? IPv6 ?? Network ????????
  ??????? Network ??????? Support ??????? Protocol
• ?????????????? ????????????????????? Support IPv6
  ??????????????????????????????????? Update
  Software/Firmware
• Tunneling
• ???????????????????????? Network IPv6 ??? IPv4
• ??? IPv4 Network ??????? IPv6 Packet ???????????
  IPv6 Packet ???? IPv4 Packet (IP Protocol 41)
• ???????????? Automatic Tunneling
  ????????????????? Tunnel ????????????????
  Tunneling End Point (???????????????????)
• ????? IPv4 ???? IPv6 ??????????????? Relay Router
  ????????? IPv6 Network

31
Automatic Tunneling

• ???????????????? ????????????? Transition ???
  IPv4 ???? IPv6
• ?????????????????? IPv6 Host ??????????????????
  IPv6 Host ???? IPv6 Network ???? IPv4
• Host ?????????????? IPv4
• ????????? Run Dual Stack ??? Host
• Dual Stack ?????????????????? Window XP ??????
• ????4in6 6in4 6over4 DS-Lite 6rd 6to4
  ISATAP NAT64 / DNS64 Teredo SIIT
• ????????? 2 ??? 6to4 ??? Teredo ??????? Enable
  ??? Default ?? Window 7/Vista

32
IPv6 over IPv4 Tunneling
33
Dual Stack Host
34
Window Implementation
Dual Stack Architecture (Window XP, 2003)
Dual IP Layer Architecture (Window Vista/2008)
35
Automatic Tunneling

• 4in6 6in4 6over4 DS-Lite 6rd 6to4
  ISATAP NAT64 / DNS64 Teredo SIIT
• ????????? 2 ??? 6to4 ??? Teredo ??????? Enable
  ??? Default ?? Window 7/Vista
• 6to4 (RFC3056)
• ???????????? ?????? Protocol 41 ????? Encapsulate
  IPv6 ???? IPv4
• 6to4 Host ??? Network ????? 2002/16 Prefix
  ??????? 6to4 Router, Host ????????????????????????
  ??? 6to4 Router ???
• 6to4 Relay Router ??????????????? IPv4 Network
  ???????????? IPv6 Network
• Relay Router ???????? 6to4 Anycast Address
• 192.88.99.1 ??? 2002C0586301
• Site ??????? /48 IPv6 Prefix ????? IPv4 Address
  ??? 6to4 Router ???????? 2002/16 ??????????????
  Tunnel ??? 6to4 Router ????? 6to4 Relay

36
6to4 Tunneling
37
6to4 Tunneling

• Example of a single computer acting as a 6to4
  router.
• IPv4 address 203.0.113.5 (in hex cb 00 71 05)
• 6to4 network prefix is 2002cb007105/48
  (2002/16 32-bit IPv4)
• Configure my IPv6 address as (subnet 1,
  interface-id 1)
• My IPv6 address 2002cb00710511
• 6to4 relay anycast IPv4 address 192.88.99.1
• 6to4 relay anycast IPv6 address 2002c0586301
• To send a packet to 2001db8abcd3, the
  computer encapsulates the IPv6 packet inside an
  IPv4 packet that is sent to the 6to4 relay IPv4
  address
• IPv4 src 203.0.113.5 IPv4 dst 192.88.99.1
• IPv6 src 2002cb00710511 IPv6 dst
  2001db8abcd3

38
Teredo Tunneling

• ???????? Microsoft ?????? Support ?? Unix/Linux
  ???????? (RFC4380)
• ????????????? IPv6 Packet ??????? UDP
  ??????????????????? IPv4 Packet
• ????????????????????? NAT ???
• ??? Special IPv6 Prefix 2001/32
• ????????????? Teredo Relays ?????????? Teredo
  Server

39
Toredo Diagram
40
6to4 vs Teredo

• 6to4 ??? Prefix 2002/16 ???? Teredo ???
  2001/32
• ????????????????? Encapsulating IPv6 ???
• 6to4 Encapsulate IPv6 ???? Payload IPv4 ??????
• Teredo ?? Encapsulate IPv6 ?? UDP ????? IPv4
• 6to4 ??? Well-Known anycast relay router
  (192.88.99.0/24) ???? Teredo ???????????

41
ISATAP

• ????????? Tunnel ?????????????? IPv6
• ????????????-??? ????????????? IPv6 Host ????
  IPv4 Network
• ????? IPv4 ??????????????? Non-broadcast ????
  NBMA (???????? ICMP6) ???????Neighbor Discovery
  ????????????????
• Router ???????? PRL Potential Router List ?????
  Unicast-Only Autoconfiguration
• Intra-Site Automatic Tunnel Addressing Protocol
• ????? IPv6 ???? IPv4 Packet ??????
• RFC 4214
• ??????????? Link-Local IPv6 Address ??? IPv4
  Address
• FE800002005efe IPv4 Address
• EX Host 192.0.2.143 ???? Link-Local IPv6 Address
  ????
• fe800002005efe192.0.2.143 ????
• fe800002005efec00028f

42
ISATAP
43
End of Chapter 24

• Homework 4 (Week 6) Download
• ?????????? 4 ??????????????? 24 ??????? ????
  12.00 ?. ??????????????????????
  ???????????????????????????

44
END OF WEEK 6

• Week 7
• No Class ?????????????????
• ???? MT ??????????(Week10) ?????????????
• ?????????????? ???? MT ??? Week 11 Monday 9
  August 2013
• MT Exam 35
• 2 August 2013 9.00 11.30, 2-1/2 hr. ????????
  Makeup Exam
• 6 ??? ????? 10 ????? ??? 60 ????? ???? 35
• ????????????????????

45
MT Exam Preparation

• 6 ??? 60 ????? ????????????????? ??????
• 1. LAN/LAN Technology ?????? Slide Week 2-3
• 2-3. IP Concept, IP Address/Subneting ??????
  Slide Week 3-4
• 4. IP Forwarding ??? IP Datagram ?????? Slide Wk
  4
• 5. Supporting Protocols ?????? Slide Week 5
• 6. IPv6 ?????? Slide Week 6
• ??????????? ??????????????????????? ??????????
• ????????????? ?????????????????????????????
  ?????????????????????? ???????????????????????????
  
• ???????????????? 15-20 ??? 35
  ?????????????????? ???????????????????? Final ????