Internet Protocol Version 6 (IPv6)Slide 2IP AddressesIP Address FormatHow Many Addresses?IPv6 EnhancementsIPv6 AddressesColon-Hex NotationLocal-Use AddressesMulticast AddressesMulticast Addresses (Cont)HeaderIP v6 HeaderProtocol and Header TypesIPv6 vs IPv4IPv6 vs IPv4 (Cont)Extension HeadersExtension Header (Cont)Hop-by-hop Options HeaderFragmentation HeaderRouting HeaderDestination OptionsSummaryReading Assignment14-1©2005 Raj JainCSE473sWashington University in St. LouisInternet Protocol Internet Protocol Version 6 (IPv6)Version 6 (IPv6)Raj Jain Washington UniversitySaint Louis, MO [email protected] slides are available on-line at:http://www.cse.wustl.edu/~jain/cse473-05/14-2©2005 Raj JainCSE473sWashington University in St. LouisLimitations of IPv4 AddressingIPv6 EnhancementsIPv6 AddressesIP v6 HeaderIPv6 Extension HeadersOverview14-3©2005 Raj JainCSE473sWashington University in St. LouisIP AddressesIP AddressesExample: 164.107.134.5 = 1010 0100 : 0110 1011 : 1000 0110 : 0000 0101= A4:6B:86:05 (32 bits)Maximum number of address = 232 = 4 BillionClass A Networks: 15 Million nodesClass B Networks: 64,000 nodes or lessClass C Networks: 254 nodes or less14-4©2005 Raj JainCSE473sWashington University in St. LouisIP Address FormatIP Address FormatThree all-zero network numbers are reserved127 Class A + 16,381 Class B + 2,097,151 Class C networks = 2,113,659 networks totalClass B is most popular.20% of Class B were assigned by 7/90 and doubling every 14 months  Will exhaust by 3/94Question: Estimate how big will you become?Answer: More than 256!Class C is too small. Class B is just right.14-7©2005 Raj JainCSE473sWashington University in St. LouisHow Many Addresses?How Many Addresses?10 Billion people by 2020Each person will be served by more than one computerAssuming 100 computers per person  1012 computersMore addresses may be required sinceMultiple interfaces per nodeMultiple addresses per interfaceSome believe 26 to 28 addresses per hostSafety margin  1015 addressesIPv6 Requirements  1012 end systems and 109 networks. Desirable 1012 to 1015 networks1-8©2005 Raj JainCSE473sWashington University in St. LouisIPv6 EnhancementsIPv6 Enhancements1. Expanded address space: 128 bit2. Address auto-configuration: Dynamic assignment 3. Increased addressing flexibility: Anycast + Multicast4. Improved option mechanism: Extension HeadersImproved speed and simplified router processing 5. Support for resource allocationReplaces type of serviceLabeling of packets to particular traffic flow14-9©2005 Raj JainCSE473sWashington University in St. LouisIPv6 AddressesIPv6 Addresses128-bit long. Fixed size2128 = 3.4×1038 addresses  665×1021 addresses per sq. m of earth surfaceIf assigned at the rate of 106/ s, it would take 20 yearsExpected to support 8×1017 to 2×1033 addresses8×1017  1,564 address per sq. mAllows multiple interfaces per host.Allows multiple addresses per interface Allows unicast, multicast, anycastAllows provider based, site-local, link-local14-10©2005 Raj JainCSE473sWashington University in St. LouisColon-Hex NotationColon-Hex NotationDot-Decimal: 127.23.45.88Colon-Hex: FEDC:0000:0000:0000:3243:0000:0000:ABCDCan skip leading zeros of each wordCan skip one sequence of zero words, e.g., FEDC::3243:0000:0000:ABCD::3243:0000:0000:ABCDCan leave the last 32 bits in dot-decimal, e.g., ::127.23.45.88Can specify a prefix by /length, e.g., 2345:BA23:0007::/5014-11©2005 Raj JainCSE473sWashington University in St. LouisLocal-Use AddressesLocal-Use AddressesLink Local: Not forwarded outside the link, FE:80::xxx0 Interface ID1111 1110 1010 bits n bits 118-nSite Local: Not forwarded outside the site, FE:C0::xxxProvides plug and play0 Subnet ID1111 1110 1110 bits n bits m bitsInterface ID118-n-m bits14-12©2005 Raj JainCSE473sWashington University in St. LouisMulticast AddressesMulticast AddressesT = 0  Permanent (well-known) multicast address, 1  TransientScope: 1 Node-local, 2 Link-local, 5 Site-local,8 Organization-local, E GlobalPredefined: 1  All nodes, 2  Routers, 1:0  DHCP servers8 bits 4 bits 4 bits 112 bitsFlags Scope1111 1111 Group ID0 0 0 T14-13©2005 Raj JainCSE473sWashington University in St. LouisMulticast Addresses (Cont)Multicast Addresses (Cont)Example: 43  Network Time Protocol ServersFF01::43  All NTP servers on this nodeFF02::43  All NTP servers on this linkFF05::43  All NTP servers in this siteFF08::43  All NTP servers in this organizationFF0E::43  All NTP servers in the Internet14-14©2005 Raj JainCSE473sWashington University in St. LouisHeaderHeaderVer Traffic Class Flow LabelPayload Length Next Header Hop LimitSource AddressDestination AddressVersion IHL Type of Service Total LengthIdentification Flags Fragment OffsetTime to Live Protocol Header ChecksumSource AddressDestination AddressPaddingOptionsIPv6:IPv4:14-15©2005 Raj JainCSE473sWashington University in St. LouisIP v6 HeaderIP v6 HeaderVersion: 6Traffic Class: Classes or priorities of packetFlow Label: Used by hosts requesting special handlingPayload length: Includes all extension headers + dataNext Header: Extension header or next layer upSource AddressDestination address14-16©2005 Raj JainCSE473sWashington University in St. LouisProtocol and Header TypesProtocol and Header TypesDecimal Keyword Header TypeHBH Hop-by-hop (IPv6)1 ICMP Internet Control Message (IPv4)2 IGMP Internet Group Management (IPv4)2 ICMP Internet Control Message (IPv6)3 GGP Gateway-to-Gateway4 IP IP in IP (IPv4 Encaptulation)5 ST Stream6 TCP17 UDP29 ISO-TP443 RH Routing Header (IPv6)44 FS Fragmentation Header (IPv6)45 IDRP Interdomain Routing51 AH Authentication header (IPv6)52 ESP Encrypted Security Payload59 Null No next header60 ISO-IP CLNP88 IGRP89 OSPF Open Shortest Path First14-17©2005 Raj JainCSE473sWashington University in St. LouisIPv6 vs IPv4IPv6 vs IPv41995 vs 1975IPv6 only twice the size of IPv4 headerOnly version number has the same position and meaning as in IPv4Removed: header length, type of service, identification, flags, fragment offset, header checksumDatagram length replaced by payload lengthProtocol type replaced by next headerTime to live replaced by hop limitAdded: Priority and flow labelAll fixed size fields.14-18©2005 Raj