IP Next Generation (IPv6)Slide 2IP AddressesIP Address FormatHow Many Addresses?Address SizeIPv6 AddressesColon-Hex NotationInitial IPv6 Prefix AllocationLocal-Use AddressesMulticast AddressesMulticast Addresses (Cont)HeaderProtocol and Header TypesIPv6 vs IPv4Slide 18Extension HeadersExtension Header (Cont)Routing HeaderProvider SelectionSummaryHomeworkRaj JainThe Ohio State University1IP Next Generation IP Next Generation (IPv6)(IPv6)Raj Jain The Ohio State UniversityColumbus, OH [email protected]://www.cse.ohio-state.edu/~jain/cis677-98/Raj JainThe Ohio State University2Limitations of current Internet Protocol (IP)How many addresses do we need?IPv6 AddressingIPv6 header formatOverviewRaj JainThe Ohio State University3IP 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 lessRaj JainThe Ohio State University4IP 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.Raj JainThe Ohio State University7How 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IPng Requirements  1012 end systems and 109 networks. Desirable 1012 to 1015 networksRaj JainThe Ohio State University8Address SizeAddress SizeH Ratio = log10(number of objects)/available bits2n objects with n bits: H-Ratio = log102 = 0.30103French telephone moved from 8 to 9 digits at 107 households  H = 0.26 (assuming 3.3 bits/digit)US telephone expanded area codes with 108 subscribers  H = 0.24SITA expanded 7-character address at 64k nodes  H = 0.14 (assuming 5 bits/char)Physics/space science net stopped at 15000 nodes using 16-bit addresses  H = 0.263 Million Internet hosts currently using 32-bit addresses  H = 0.20  A few more years to goRaj JainThe Ohio State University9IPv6 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-localRaj JainThe Ohio State University10Colon-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:BA23:7::/40Raj JainThe Ohio State University11Initial IPv6 Prefix AllocationInitial IPv6 Prefix AllocationPrefixUnassigned0000 0000Allocation Allocation PrefixReserved 101Unassigned 0000 0001 Unassigned 110NSAP 0000 001 Unassigned 1110IPX 0000 010 Unassigned 1111 0Unassigned 0000 011 Unassigned 1111 10Unassigned 0000 1 Unassigned 1111 110Unassigned 0001 Unassigned 1111 1110Unassigned 001 Unassigned 1111 1110 0Provider-based 010 Link-Local 1111 1110 10Unassigned 011 Site-Local 1111 1110 11Geographic 100 Multicast 1111 1111Raj JainThe Ohio State University12Local-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 bitsRaj JainThe Ohio State University13Multicast 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 TRaj JainThe Ohio State University14Multicast 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FF0F::43  All NTP servers in the InternetRaj JainThe Ohio State University15HeaderHeaderVersion Priority 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:Raj JainThe Ohio State University16Protocol 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 FirstRaj JainThe Ohio State University17IPv6 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.Raj JainThe Ohio State University18No optional fields. Replaced by extension headers.8-bit hop limit = 255 hops max (Limits