Other Benefits of IPv6 工Pv6 server-less plug-and-play possible end-to-end, IP-layer authentication& encryptio Background elimination of "triangle routing" for mobile IP other minor improvements NON-benefits: Deployment Strategies Current status except customer multihoming is defeating hierarch IPv6 Header compared to He eader Summary of Header Changes Ver rs Revised PayloadLength HEatr mit Addresses increased 32 bits- 128 bits Protocol-, Next Header estination Address elds moved out of base header shier ye risios have no equialent in cludes IPv6 header Alignment changed from 32 to 64 bits Extended Flow Label field added Text Representation of Text Representation of Addresses Addresses(cont preferred"form address prefix: 2002: 43c: 476b: /48 10800:FF:08:800:200C:417A (note: no masks in IPv6!) compressed form: FF01: 0: 0: 0: 0: 0: 0: 43 zone qualifiers: FE80: 800: 200C: 417A73 becomes FF01: 43 in URLs: http∥[3FFE:1:800:200C:417A:8000 0:FFFF:131683 racket convention also used else theres a conf lict with address syntax) :FFFF:13168.315 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 85 Other Benefits of IPv6 „ server-less plug-and-play possible „ end-to-end, IP-layer authentication & encryption possible „ elimination of “triangle routing” for mobile IP „ other minor improvements NON-benefits: „ quality of service (same QoS capabilities as IPv4) „ flow label field in IPv6 header may enable more efficient flow classification by routers, but does not add any new capability „ routing (same routing protocols as IPv4) „ except larger address allows more levels of hierarchy „ except customer multihoming is defeating hierarchy 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 86 IPv6 „ Background „ Technology Overview „ Deployment Strategies „ Current Status 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 87 IPv6 Header compared to IPv4 Header Ver. Time to Live Source Address Total Length Type of Service Hdr Len Identification Fragment Offset Flg Protocol Header Checksum Destination Address Options... Ver. Traffic Class Source Address Payload Length Next Header Hop Limit Destination Address Hdr Len Identification Fragment Offset Flg Header Checksum Options... shaded fields have no equivalent in the other version IPv6 header is twice as long (40 bytes) as IPv4 header without options (20 bytes) Flow Label 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 88 Summary of Header Changes „ Revised „ Addresses increased 32 bits -> 128 bits „ Time to Live -> Hop Limit „ Protocol -> Next Header „ Type of Service -> Traffic Class „ Streamlined „ Fragmentation fields moved out of base header „ IP options moved out of base header „ Header Checksum eliminated „ Header Length field eliminated „ Length field excludes IPv6 header „ Alignment changed from 32 to 64 bits „ Extended „ Flow Label field added 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 89 Text Representation of Addresses “preferred” form: 1080:0:FF:0:8:800:200C:417A compressed form: FF01:0:0:0:0:0:0:43 becomes FF01::43 IPv4-embedded: 0:0:0:0:0:FFFF:13.1.68.3 or ::FFFF:13.1.68.3 哈工大计算机学院 李全龙 Network Application Development 1: Introduction 90 Text Representation of Addresses (cont.) address prefix: 2002:43c:476b::/48 (note: no masks in IPv6!) zone qualifiers: FE80::800:200C:417A%3 in URLs: http://[3FFE::1:800:200C:417A]:8000 (square-bracket convention also used anywhere else there’s a conflict with address syntax)