1、2022/7/15TCP/IP Protocol Suite1Chapter 14 IPv6 and ICMPv6IPv6IPv6 addressesIPv6 packet formatICMPv6Transition from IPv4 to IPv62022/7/15TCP/IP Protocol Suite2Introduction：Deficiencies of IPv4編址The use of IPv4 address space is inefficientSize: 32bitStructure: Net id + Subnet id + Host idClass: A、B、C、

2、D、E子網和超網技術使得路由選擇復雜QoSIPv4 Best-effort而對于實時傳輸的音頻和視頻業務，需要IP傳輸提供最小時延策略和預留資源機制SecurityIPv4：No encryption or authentication2022/7/15TCP/IP Protocol Suite3IPv6Intention: to succeed to IPv4（RFC 791）ImprovementsAddressing and routingIncreases the IP address size to 128 bitsMore levels of addressing and rout

3、ing hierarchyPacket formatBase header and optional extension headersNetwork management technologiesAuto-discovery technologies: MTU, neighbor, router, etc.Auto-configuration technologies: IPv6 address, etc.( cont. )2022/7/15TCP/IP Protocol Suite4Improvements ( cont. )Security supportAuthentication:

4、IPsec AH Encryption: IPSec ESPQoS suppoutFlow labelingMobility supportSome options: destination option, routing option Auto-configurationSecurity and QoS technologiesAnycast addresses2022/7/15TCP/IP Protocol Suite5Chapter 14 IPv6 and ICMPv6IPv6IPv6 addressesIPv6 packet formatICMPv6Transition from IP

5、v4 to IPv62022/7/15TCP/IP Protocol Suite6IPv6 AddressesFDECBA9876543210AEBFBBFF2922FFFF:1111110111101100 1111111111111111128 bits = 16 bytes = 32 hex digitsHexadecimal colon notationRFC 35132022/7/15TCP/IP Protocol Suite7Hexadecimal colon notationAbbreviationThe leading zeros of a section can be omi

6、ttedFDEC : BA98 : 0074 : 3210 : 000F : BBFF : 0000 : FFFFFDEC : BA98 : 74 : 3210 : F : BBFF : 0 : FFFFA double colon can be used to replace consecutive sections consisting of zerosFDEC : 0 : 0 : 0 : F : 0 : 0 : FFFFFDEC : : F : 0 : 0 : FFFFHybrid of IPv4 and IPv6x : x : x : x : x : x : d . d . d . d

7、Only once per address x: hexadecimal, 16bit d: decimal, 8bit2022/7/15TCP/IP Protocol Suite8CIDR NotationIPv6-address / prefix-lengthExample: the 60-bit prefix 12AB00000000CD3Legal representations12AB : 0 : 0 : CD30 : 0 : 0 : 0 : 0 / 6012AB : : CD30 : 0 : 0 : 0 : 0 / 6012AB : 0 : 0 : CD30 : : / 60Ill

8、egal representations12AB : 0 : 0 : CD30 / 6012AB : : CD30 / 6012AB : : CD3 / 60 12AB : 0 : 0 : 0 : 0 : 0 : 0 : CD30 / 60 12AB : 0 : 0 : 0 : 0 : 0 : 0 : 0CD3 / 60 Represent 64-bit, not 128-bit2022/7/15TCP/IP Protocol Suite9Categories of AddressesUnicast: an identifier for a single interfaceLike IPv4

9、host addressMulticast: an identifier for a set of interfacesMay or may not be connected to the same networkA packet sent to a multicast address is delivered to all interfaces identified by that addressLike IPv4 multicast or broadcast addressAnycast（任播）: an identifier for a set of interfacesA packet

10、sent to an anycast address is delivered to one the interface identified by that address the nearest one, according to the routing protocols measure of distance例如利用anycast功能用戶可以訪問到離他最近的DNS服務器和文件服務器2022/7/15TCP/IP Protocol Suite10Address Space Assignment128 bitsType PrefixRest of addressVariableVariab

11、lePrefixAddress type: : /128Unspecified: : 1 /128LoopbackFF00 : : /8MulticastFE80 : : /10Link-local unicastFEC0 : : /10Site-local unicastOthersGlobal unicastAnycast addresses are taken from the unicast spaces2022/7/15TCP/IP Protocol Suite11Unicast AddressesInterface identifiersIdentify interfaces on

12、 a linkBe derived directly from the interfaces link-layer address64 bits long, Modified EUI-64 formatUnspecified address : : / 128like 0.0.0.0 in IPv4 address spaceLoopback address : : 1 / 128like 127.0.0.0 127.255.255.255 in IPv4 address spaceGlobal unicast addressesIPv6 addresses with embedded IPv

13、4 addressesLocal-use IPv6 unicast addresses2022/7/15TCP/IP Protocol Suite12Global Unicast AddressesGeneral formatGlobal routing prefixn bitsSubnet IDInterface IDm bits128-n-m bitsAssign to a site（a cluster or subnets/links）An ID of a link within the siteAll global unicast addresses other than those

14、start with binary 000 have a 64-bit interface ID2022/7/15TCP/IP Protocol Suite13IPv6 Addresses with Embedded IPv4 AddressesIPv4-compatible IPv6 addressThe hosts and routers dynamically tunnel IPv6 packets over IPv4 routing infrastructure: : d . d . d . d兩臺IPv6計算機通信，要穿越IPv4的網絡IPv4-mapped IPv6 address

15、Represent the addresses of IPv4 nodes as IPv6 addresses: : FFFF : d . d . d . dIPv6主機與IPv4主機通信2022/7/15TCP/IP Protocol Suite14Local-Use IPv6 Unicast AddressesLink-Local addressUse on a single linkUsage: auto-configuration, neighbor discovery, or when no routers are present Site-Local addressUse in a

16、 single siteUsage: no need for a global prefix111111101010 bits0Interface ID54 bits64 bits111111101110 bitsSubnet IDInterface ID54 bits64 bitsLike IPv4 private addressesRouter must not forward any packet with link-local source or destination addresses to other links2022/7/15TCP/IP Protocol Suite15Mu

17、lticast AddressesFormat111111118 bits112 bitsFlag4 bitsScope4 bitsGroup ID0000permanent0001transient0001interface-local0010link-local0100admin-local0101site-local1000organization-local1110global2022/7/15TCP/IP Protocol Suite16Anycast AddressesFormatUsing any of the defined unicast address formatsWhe

18、n a unicast address is assigned to more than one interface, thus turning it into an anycast addressUsageIdentify the set of routers belonging to an organization providing internet serviceIdentify the set of routers attached to a particular subnet，or the set of routers providing entry into a particul

19、ar routing domainRestrictionMust not be used as the source address of an IPv6 packetMust not be assigned to an IPv6 host2022/7/15TCP/IP Protocol Suite17A Nodes Required AddressesHostLink-Local address for each interfaceAny additional Unicast and Anycast addresses that have been configured for its in

20、terfacesLoopback addressMulticast address: All-Nodes, all groups it belongs toRouterA hosts required addressesAnycast addresses it has been configuredAll-Routers Multicast addresses2022/7/15TCP/IP Protocol Suite18Chapter 14 IPv6 and ICMPv6IPv6IPv6 addressesIPv6 packet formatICMPv6Transition from IPv

21、4 to IPv62022/7/15TCP/IP Protocol Suite19IPv6 Packet FormatRFC 24602022/7/15TCP/IP Protocol Suite20Base Header Format2022/7/15TCP/IP Protocol Suite21Extension Header Format2022/7/15TCP/IP Protocol Suite22Extension HeaderHop-by-Hop OptionsRoutingFragmentDestination OptionsAuthenticationEncapsulating

22、Security Payload2022/7/15TCP/IP Protocol Suite23Comparison between IPv4 and IPv6 HeadersEliminatedHLEN、ChecksumReplacedToS priority and flow labelTotal length payload lengthProtocol next headerTTL hop limitImplemented as extension headersFragment: identification / flag / offsetOptions2022/7/15TCP/IP

23、 Protocol Suite24Chapter 14 IPv6 and ICMPv6IPv6IPv6 addressesIPv6 packet formatICMPv6Transition from IPv4 to IPv62022/7/15TCP/IP Protocol Suite25ICMPv6Network layer in IPv6Delete RARPICMP, ARP and IGMP ICMPv6ICMPv6Error and informational messages（RFC 2463）Neighbor Discovery Protocol for IPv6, RFC 24

24、61 & 3122Multicast Listener Discovery for IPv6, RFC 27102022/7/15TCP/IP Protocol Suite26ICMPv6 Error MessagesTypes of MessageVersion 4Version 6Destination UnreachableTime ExceededParameter ProblemSource QuenchRedirect（NDP）Packet Too Big2022/7/15TCP/IP Protocol Suite27ICMPv6 Information MessagesTypes

25、 of messagesVersion 4Version 6Echo RequestEcho ReplyTimestamp RequestTimestamp ReplyInformation RequestInformation Reply2022/7/15TCP/IP Protocol Suite28Neighbor Discovery Protocolfor IPv6FunctionMessageRouter and prefix discoveryRouter solicitationRouter advertisementAddress resolution and neighbor unreachability detectionNeighbor solicitationNeighbor advertisementRedirectRedirect2022/7/15TCP/IP Protocol Suite29Chapter 14 IPv6 and ICMPv6IPv6IPv6 addressesIPv6 packet formatICMPv6Transition from IPv4 to IPv62022/7/15TCP/IP Protocol Suite30Transition fr