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现代通信新技术导论 第三章 IPv6 与移动 IP Chapter 3 IPv6 and Mobile IP 电控学院 电子工程学科部 司鹏搏 综合楼 825 室

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Presentation on theme: "现代通信新技术导论 第三章 IPv6 与移动 IP Chapter 3 IPv6 and Mobile IP 电控学院 电子工程学科部 司鹏搏 综合楼 825 室"— Presentation transcript:

1 现代通信新技术导论 第三章 IPv6 与移动 IP Chapter 3 IPv6 and Mobile IP 电控学院 电子工程学科部 司鹏搏 综合楼 825 室

2 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 –3.1.1 Problems of IPv4 –3.1.2 Solve the Problems –3.1.3 IPv6 Address –3.1.4 IPv6 Header –3.1.5 Address Allocation –3.1.6 IPv6 Routing –3.1.7 IPv6 in China 3.2 Mobile IP

3 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 3.2 Mobile IP –3.2.1 Introduction to Mobile IP –3.2.2 Operations of Mobile IP –3.2.3 Problems with Mobile IP –3.2.4 Mobility in IPv6

4 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 –3.1.1 Problems of IPv4 –3.1.2 Solve the Problems –3.1.3 IPv6 Address –3.1.4 IPv6 Header –3.1.5 Address Allocation –3.1.6 IPv6 Routing –3.1.7 IPv6 in China 3.2 Mobile IP

5 现代通信新技术导论 第三章 IPv6 and Mobile IP Problems of IPv4 Toooooooooooooooooooooold Exhaustion of IPv4 addresses –4 bytes = 4.3 billion –Much less than the human population (6.1 billion) –Will be exhausted in around 2008 (previous prediction) –Registries are allocating IPv4 addresses by severe policy –Nobody can obtain enough IPv4 addresses Increment of routing information –Routing information cannot be aggregated effectively –Unaggregatable address assignments –80,000 entries at present –Burden for backbone routers –Unstability, accidents

6 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 –3.1.1 Problems of IPv4 –3.1.2 Solve the Problems –3.1.3 IPv6 Address –3.1.4 IPv6 Header –3.1.5 Address Allocation –3.1.6 IPv6 Routing –3.1.7 IPv6 in China 3.2 Mobile IP

7 现代通信新技术导论 第三章 IPv6 and Mobile IP Two Ways to Ease the Problems NAT (Network Address Translation) –Intranet IP address is introduced –Protect the interior hosts –IP address translation –Visits from exterior hosts are inconvenient CIDR (Classless Inter-Domain Routing) –Subnets could be even smaller than Class C networks –Layered architecture to reduce the size of routing table However, the technologies are not the ways to thoroughly workout the problems

8 现代通信新技术导论 第三章 IPv6 and Mobile IP Two Ways to Ease the Problems Patched Internet by NAT –Unidirectional communication –Enclosed communication Single point of failure Evolution of application are suppressed Accounting from servers is impossible Flat Internet –Bidirectional communication –End-to-end communication True communication infrastructure Much easier to deploy inventive new applications

9 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv Solve the Problems Exhaustion of IP address Increment of routing information IPv6 Significant extension of address space Auto- Config Layered Address QoS Secure IPv4 NAT CIDR Temporary counter measure The thorough solution Finally

10 现代通信新技术导论 第三章 IPv6 and Mobile IP Towards IPv6 Address extension and starting over –16 bytes = 3.4×10 38 v.s. 4 bytes = 4.3×10 9 –Some technologies are mandatory Plug and play End-to-end security (i.e., IPsec) At least subnets –Class A per site Reducing external routing information to 8192 –Aggregatable global address End-to-end and bidirectional communication –A NAT-free world –Paradigm change for applications Cellular phones, automobiles, home networks, game machines, … IPv9?

11 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 –3.1.1 Problems of IPv4 –3.1.2 Solve the Problems –3.1.3 IPv6 Address –3.1.4 IPv6 Header –3.1.5 Address Allocation –3.1.6 IPv6 Routing –3.1.7 IPv6 in China 3.2 Mobile IP

12 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv6 Address Format FP= Format Prefix (= 001 for globally aggregated unicast addresses) TLA-ID= Top-level aggreation identifier RES= Reserved for future use NLA= Next-level aggregation identifier SLA-ID= Site-level aggregation identifier Interface ID= Interface identifier Interface-IDFPTLA-IDResNLA-IDSLA-ID ≥3≥3≤ bit Public Topology Site Topology Interface Identifier Network Portion Node Portion

13 现代通信新技术导论 第三章 IPv6 and Mobile IP Address Notation Separate 4 figures of hexadecimal by “:” –3ffe:0501:0008:1234:0260:97ff:fe40:efab –ff02:0000:0000:0000:1111:0000:0000:0001 Preceding 0 for each piece can be omitted –3ffe:501:8:1234:260:97ff:fe40:efab –ff02:0:0:0:1111:0:0:1 Continuous 0 pieces can be expressed by “::” at most once –ff02::1111:0:0:1 or ff02:0:0:0:1111::1 is OK –ff02::1111::1 is not OK Prefix length is placed after “/” –3ffe:500/25

14 现代通信新技术导论 第三章 IPv6 and Mobile IP 0000 Reserved Unassigned Reserved for NSAP (non-IP addresses used by ISO) Reserved for IPX (non-IP addresses used by IPX) Unassigned Unassigned 0001Unassigned 001Unicast Address Space 010Unassigned 011Unassigned 100Unassigned 101Unassigned 110Unassigned 1110Unassigned Unassigned Unassigned Unassigned Unassigned Link Local Use addresses Site Local Use addresses 1111 Multicast addresses

15 现代通信新技术导论 第三章 IPv6 and Mobile IP Special Addresses All zero –Represents absence of an address ::1 –Analogous to IPv4 loopback fe8/10 –Meaningful only to nodes on a single link within a single site –NOT globally unique, unique only within respective scope –Used for autoconfiguration, neighbor discovery, nodes on routerless links, routing protocols fe9/10 –To be used within a site only –NOT globally unique –NOT to be propagated beyond site boundaries –Edge routers MUST keep site-local traffic within site

16 现代通信新技术导论 第三章 IPv6 and Mobile IP Anycast Address Used to address multiple interfaces on different nodes with SAME IPv6 address Allocated from unicast address space Addresses are taken from Interface-ID field Currently, only specified anycast addresses are for subnet-router and for Mobile IPv6 home-agents –Subnet-router Subnet prefix followed by zeros E.g., fec0:0:0:A:: representing the nearest router in the subnet

17 现代通信新技术导论 第三章 IPv6 and Mobile IP Multicast Address Always begin with ff Two types –Well-known – assigned by an official authority –Transient – locally assigned for non-global use Multicast addresses are scoped Currently 5 scope levels defined: –Local to the node (scope = 1, node-local) –Local to the link (scope = 2, link-local) –Local to the site (scope = 5, site-local) –Local to the organization (scope = 8) –Global (scope = E) –Reserved (scope = 0 and scope = F)

18 现代通信新技术导论 第三章 IPv6 and Mobile IP Multicast Address Format Group-ID flgs bit scope 4 First 3 bits set to 0 Last bit defines address type: 0 = Permanent (or well-known) 1 = Locally assigned (or transient) Defines address scope 0Reserved 1Node-local scope 2Link-local scope 5Site-local scope 8Organization local scope EGlobal scope FReserved

19 现代通信新技术导论 第三章 IPv6 and Mobile IP Well-known Multicast Addresses IPv6 Well-known multicast address IPv4 Well-known multicast address Multicast Group Node-local scope FF01:0:0:0:0:0:0: All-nodes address FF01:0:0:0:0:0:0: All-routers address Link-local scope FF02:0:0:0:0:0:0: All-nodes address FF02:0:0:0:0:0:0: All-routers address FF02:0:0:0:0:0:0: OSPFIGP FF02:0:0:0:0:0:0: OSPFIGP-DR‘s FF02:0:0:0:0:0:0: RIP routers FF02:0:0:0:0:0:0:D All PIM routers Site-local scope FF05:0:0:0:0:0:0: All-routers address Any valid scope FF0X:0:0:0:0:0:0: Network time protocol NTP

20 现代通信新技术导论 第三章 IPv6 and Mobile IP Unicast Address Assignment in v6 Unicast address assignment is similar to CIDR –Unicast addresses start with 001 –Host interfaces belong to subnets –Addresses are composed of a subnet prefix and a host identifier –Subnet prefix structure provides for aggregation into larger networks Provider-based plan –Idea is that the Internet is global hierarchy of network –Three levels of hierarchy – region, provider, subscriber –Goal is to provide route aggregation to reduce BGP overhead A provider can advertise a single prefix for all of its subscribers –Region = 13 bits, Provider = 24 bits, Subscriber = 16 bits, Host = 80 bits Eg. 001,regionID,providerID,subscriberID,subnetID,intefaceID –What about multi-homed subscribers? No simple solution Anycast addresses are treated just like unicast addresses –It’s up to the routing system to determine which server is “closest”

21 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 –3.1.1 Problems of IPv4 –3.1.2 Solve the Problems –3.1.3 IPv6 Address –3.1.4 IPv6 Header –3.1.5 Address Allocation –3.1.6 IPv6 Routing –3.1.7 IPv6 in China 3.2 Mobile IP

22 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv4 vs. IPv6 Header Formats Ver. 6 Ver. 6 Traffic class 8 bits Traffic class 8 bits Flow label 20 bits Flow label 20 bits Payload Length 16 bits Payload Length 16 bits Next Hdr. 8 bits Next Hdr. 8 bits Hop Limit 8 bits Hop Limit 8 bits Source Address 128 bits Source Address 128 bits Destination Address 128 bits Destination Address 128 bits 32 bits Ver. 4 Ver. 4 HL Datagram Length TOS Datagram-ID Flags Flag Offset TTL Protocol Header Checksum Source IP Address Destination IP Address IP Options (with padding if necessary) 32 bits IPv4 header IPv6 header Options Variable bits Options Variable bits Data

23 现代通信新技术导论 第三章 IPv6 and Mobile IP Key Differences No checksum –Bit level errors are checked for all over the place No length variability in header –Fixed format speeds processing No more fragmentation and reassembly in header –Incorrectly sized packets are dropped and message is sent to sender to reduce packet size –Hosts should do path MTU discovery –But of course we have to be able to segment packets! What about UDP packets?

24 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv6 Extension Headers IPv6 header NH=TCP TCP header + data Routing header NH=TCP IPv6 header NH=Routing IPv6 header NH=Routing Routing header NH=Fragment Fragment header NH=TCP TCP header + data

25 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv6 Extension Headers Value (Hexadecimal)Value (Decimal)Protocol / Extension Header 000Hop-By-Hop Options Extension Header 011ICMPv4 022IGMPv4 044IP in IP Encapsulation 066TCP 088EGP 1117UDP 2941IPv6 2B43Routing Extension Header 2C44Fragmentation Extension Header 2E46Resource Reservation Protocol (RSVP) 3250Encrypted Security Payload (ESP) Extension Header 3351Authentication Header (AH) Extension Header 3A58ICMPv6 3B59No Next Header 3C60Destination Options Extension Header

26 现代通信新技术导论 第三章 IPv6 and Mobile IP Routing Extension Without this header, routing is essentially the same as v4 With this header essentially same as the source routing option in v4 –Next header: 34 Header length is in 64-bit words Up to 24 addresses can be included –Packet will go to nearest of these in “anycast” configuration Next headerHd. Ext. Len 0 Segmnts left 1 – 24 addresses

27 现代通信新技术导论 第三章 IPv6 and Mobile IP Fragmentation Extension Similar to v4 fragmentation –Implemented as an extension header Placed between v6 header and data (if it is the only extension used) –13 bit offset –Last-fragment mark (M) –Larger fragment ID field than v4 Fragmentation is done on end host next headerreservedoffsetMreserved ID

28 现代通信新技术导论 第三章 IPv6 and Mobile IP Authentication Extension Next header value: 51 Provides data integrity and authentication 0 31 next headerPayload lengthreserved Security Parameters Index (SPI) Sequence Number Field Authentication Data

29 现代通信新技术导论 第三章 IPv6 and Mobile IP Encapsulating Security Payload Extension Next header value: 50, provides confidentiality, data origin authentication, connectionless integrity and anti-replay service 0 31 Security Parameters Index (SPI) Sequence Number Payload Data Padding Pad LengthNext Header Authentication Data

30 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 –3.1.1 Problems of IPv4 –3.1.2 Solve the Problems –3.1.3 IPv6 Address –3.1.4 IPv6 Header –3.1.5 Address Allocation –3.1.6 IPv6 Routing –3.1.7 IPv6 in China 3.2 Mobile IP

31 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv6 Address Allocation IPv6 address space is allocated by the 5 RIRs: –AFRINIC, APNIC, ARIN, LACNIC, RIPE-NCC –ISPs get address space from the RIRs –Enterprises get their IPv6 address space from their ISP Larger address space enables: –Aggregation of prefixes announced in the global routing table –Efficient and scalable routing Lowest order 64-bit field of unicast address may be assigned in several different ways: –Auto-configured from a 64-bit EUI-64, or expanded from a 48-bit MAC address (e.g., Ethernet address) –Auto-generated pseudo-random number (to address privacy concerns) –Assigned via DHCP –Manually configured

32 现代通信新技术导论 第三章 IPv6 and Mobile IP EUI fc 0f fc 0f ff fe fc 0f ff fe fc 0f ff fe MAC Address Add ff:fe NOT (the 7 th bit) EUI-64 address

33 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 –3.1.1 Problems of IPv4 –3.1.2 Solve the Problems –3.1.3 IPv6 Address –3.1.4 IPv6 Header –3.1.5 Address Allocation –3.1.6 IPv6 Routing –3.1.7 IPv6 in China 3.2 Mobile IP

34 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv6 Routing As in IPv4, IPv6 has 2 families of routing protocols IGP –RIPng (RFC 2080) –EIGRP for IPv6 –OSPFv3 (RFC 2740) –Integrated IS-ISv6 (draft-ietf-isis-ipv6-02) EGP –MP-BGP4 (RFC 2858 and RFC 2545) Still uses the longest-prefix match routing algorithm

35 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv6 Routing Protocols RIPng –For the ISP industry, simply don’t go here –ISPs do not use RIP in any form unless there is absolutely no alternative And there usually is –RIPng was used in the early days of the IPv6 test network Sensible routing protocols such as OSPF and BGP rapidly replaced RIPng when they became available EIGRP –Cisco EIGRP has had IPv6 protocol support added –Uses similar CLI to existing IPv4 protocol support –Easy deployment path for existing IPv4 EIGRP users

36 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 –3.1.1 Problems of IPv4 –3.1.2 Solve the Problems –3.1.3 IPv6 Address –3.1.4 IPv6 Header –3.1.5 Address Allocation –3.1.6 IPv6 Routing –3.1.7 IPv6 in China 3.2 Mobile IP

37 现代通信新技术导论 第三章 IPv6 and Mobile IP CERNET2 in China

38 现代通信新技术导论 第三章 IPv6 and Mobile IP

39 3.1.7 IPv6 Address Allocation in CERNET2 代码地址段所有单位 BJ2001:DA8:0200::/48 清华大学 BJ2001:DA8:0201::/48 北京大学 BJ2001:DA8:0202::/48 北京邮电大学 BJ2001:DA8:0203::/48 北航大学 BJ2001:DA8:0204::/48 北京理工大学 BJ2001:DA8:0205::/48 北京交通大学 BJ2001:DA8:0206::/48 北京城市学院 BJ2001:DA8:0207::/48 北京师范大学 BJ2001:DA8:0208::/48 北京科技大学 BJ2001:DA8:0209::/48 首都经济贸易大学 BJ2001:DA8:020A::/48 北方工业大学 BJ2001:DA8:020B::/48 国家计算机网络应急技术处理协调中心 BJ2001:DA8:020C::/48 华北电力大学 ( 北京 ) BJ2001:DA8:020D::/48 赛尔网络有限公司 IDC 部门 BJ2001:DA8:020E::/48 中国传媒大学 BJ2001:DA8:020F::/48 北京外国语大学 BJ2001:DA8:0210::/48 北京机械工业学院 BJ2001:DA8:0211::/48 北京林业大学 BJ2001:DA8:0212::/48 北京信息工程学院 BJ2001:DA8:0213::/48 教育部科技发展中心 BJ2001:DA8:0214::/48 中国地质大学 ( 北京 ) BJ2001:DA8:0215::/48 北京邮电大学 BJ2001:DA8:0216::/48 北京工业大学 BJ2001:DA8:0217::/48 DRAGONLAB 实验室 BJ2001:DA8:0218::/48 首都师范大学 代码地址段所有单位 CD2001:DA8:6000::/48 电子科技大学 CHC2001:DA8:B000::/48 吉林大学 CHC2001:DA8:B001::/48 东北电力学院 CHQ2001:DA8:C800::/48 重庆大学 CHQ2001:DA8:C801::/48 重庆交通大学 CHS2001:DA8:D000::/48 中南大学 DLN2001:DA8:A800::/48 大连理工大学 DLN2001:DA8:A801::/48 大连海事大学 DLN2001:DA8:A802::/48 大连轻工业学院 GZ2001:DA8:2000::/48 华南理工大学 GZ2001:DA8:2001::/48 广州市教育局 HEF2001:DA8:D800::/48 中国科技大学 HEF2001:DA8:D801::/48 解放军电子工程学院 HEF2001:DA8:D802::/48 安徽理工大学 HEF2001:DA8:D803::/48 安徽中医学院 HEF2001:DA8:D804::/48 皖南医学院 HEF2001:DA8:D805::/48 合肥工业大学 HRB2001:DA8:B800::/48 哈尔滨工业大学 HRB2001:DA8:B801::/48 哈尔滨工业大学 HZH2001:DA8:E000::/48 浙江大学 HZH2001:DA8:E001::/48 浙江工业大学 HZH2001:DA8:E002::/48 浙江大学宁波理工学院 JNN2001:DA8:7000::/48 山东大学 JNN2001:DA8:7001::/48 山东大学齐鲁软件学院 JNN2001:DA8:7002::/48 CERNET 山东省网络中心

40 现代通信新技术导论 第三章 IPv6 and Mobile IP IPv6 Address Allocation in CERNET2 代码地址段所有单位 JNN2001:DA8:7003::/48 山东大学威海分校 JNN2001:DA8:7004::/48 山东农业大学 JNN2001:DA8:7005::/48 济南大学 JNN2001:DA8:7006::/48 石油大学 ( 华东 ) JNN2001:DA8:7007::/48 石油大学 ( 华东 ) 青岛校区 JNN2001:DA8:7008::/48 山东理工大学 JNN2001:DA8:7009::/48 烟台大学 JNN2001:DA8:700A::/48 烟台师范学院 JNN2001:DA8:700B::/48 山东省计算中心 JNN2001:DA8:700C::/48 山东财政学院 LZH2001:DA8:C000::/48 兰州大学 LZH2001:DA8:C001::/48 甘肃省教育和科研计算机网 LZH2001:DA8:C002::/48 甘肃政法学院 LZH2001:DA8:C003::/48 西北师范大学 NJ2001:DA8:1000::/48 CERNET2 核心节点 - 南京 NJ2001:DA8:1001::/48 江苏省教育和科研计算机网 NJ2001:DA8:1002::/48 东南大学 NJ2001:DA8:1003::/48 南京师范大学 NJ2001:DA8:1004::/48 河海大学 NJ2001:DA8:1005::/48 南京农业大学 NJ2001:DA8:1006::/48 南京航空航天大学 NJ2001:DA8:1007::/48 南京大学 NJ2001:DA8:1008::/48 江苏工业学院 NJ2001:DA8:1009::/48 河海大学常州校区 NJ2001:DA8:100A::/48 苏州大学 SH2001:DA8:8000::/48 上海交通大学 SH2001:DA8:8001::/48 复旦大学 SH2001:DA8:8002::/48 同济大学 SH2001:DA8:8003::/48 上海交通大学 - 上海城域网 代码地址段所有单位 SH2001:DA8:8004::/48 华东工业大学 SH2001:DA8:8005::/48 华东师范大学 SH2001:DA8:8006::/48 上海大学 SH2001:DA8:8007::/48 华东理工大学 SH2001:DA8:8008::/48 东华大学 SH2001:DA8:8009::/48 上海市教育委员会 SH2001:DA8:800A::/48 上海第二医科大学 SH2001:DA8:800B::/48 上海师范大学 SH2001:DA8:800C::/48 第二军医大学 SH2001:DA8:800D::/48 上海财经大学 SH2001:DA8:800E::/48 上海外国语大学 SH2001:DA8:800F::/48 上海建桥学院 SY2001:DA8:9000::/48 东北大学 SY2001:DA8:9001::/48 辽宁大学 TJN2001:DA8:A000::/48 天津大学 TJN2001:DA8:A001::/48 天津理工大学 TJN2001:DA8:A002::/48 天津医科大学 WH2001:DA8:3000::/48 华中科技大学 WH2001:DA8:3001::/48 华中师范大学 WH2001:DA8:3002::/48 华中农业大学 XA2001:DA8:4000::/48 西安交通大学 XMN2001:DA8:E800::/48 厦门大学 ZHZ2001:DA8:5000::/48 郑州大学 ZHZ2001:DA8:5001::/48 河南财经学院 ZHZ2001:DA8:5002::/48 解放军信息工程大学 ZHZ2001:DA8:5003::/48 河南省财经学校 ZHZ2001:DA8:5004::/48 河南省教育科研网 ZHZ2001:DA8:5005::/48 郑州大学西亚斯国际学院

41 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents 3.1 IPv6 3.2 Mobile IP –3.2.1 Introduction to Mobile IP –3.2.2 Operations of Mobile IP –3.2.3 Problems with Mobile IP –3.2.4 Mobility in IPv6

42 现代通信新技术导论 第三章 IPv6 and Mobile IP We’re not Quite Done with IP You’re probably sick and tired of hearing about all things IP –Forwarding, routing, multicast, etc… One last topic we must cover because it’s going to be important in the future – mobile networking –Examples of mobile networking today? –Examples of mobile networking tomorrow? Mobile networking should not be confused with portable networking –Portable networking requires connection to the same ISP

43 现代通信新技术导论 第三章 IPv6 and Mobile IP Portable Networking Technology Cellular systems –Cellular Digital Packet Data (CDPD) –3G Bluetooth –Low cost, short range radio links between mobile devices Wireless Ethernet (802.11) –Widely used wireless MAC layer technology

44 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobility and Standard IP Routing IP assumes end hosts are in fixed physical locations –What happens if we move a host between networks? IP addresses enable IP routing algorithms to get packets to the correct network –Each IP address has network part and host part This keeps host specific information out of routers –DHCP is used to get packets to end hosts in networks This still assumes a fixed end host What if a user wants to roam between networks? –Mobile users don’t want to know that they are moving between networks –Why can’t mobile users change IP when running an application?

45 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobile IP Mobile IP was developed as a means for transparently dealing with problems of mobile users –Enables hosts to stay connected to the Internet regardless of their location –Enables hosts to be tracked without needing to change their IP address –Requires no changes to software of non-mobile hosts/routers –Requires addition of some infrastructure –Has no geographical limitations –Requires no modifications to IP addresses or IP address format –Supports security Could be even more important than physically connected routing IETF standardization process is still underway

46 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobile IP Entities Mobile Node (MN) –The entity that may change its point of attachment from network to network in the Internet Detects it has moved and registers with “best” FA –Assigned a permanent IP called its home address to which other hosts send packets regardless of MN’s location Since this IP doesn’t change it can be used by long-lived applications as MN’s location changes Home Agent (HA) –This is router with additional functionality –Located on home network of MN –Does mobility binding of MN’s IP with its COA –Forwards packets to appropriate network when MN is away Does this through encapsulation

47 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobile IP Entities Foreign Agent (FA) –Another router with enhanced functionality –If MN is away from HA the it uses an FA to send/receive data to/from HA –Advertises itself periodically –Forward’s MN’s registration request –Decapsulates messages for delivery to MN Care-of-address (COA) –Address which identifies MN’s current location –Sent by FA to HA when MN attaches –Usually the IP address of the FA Correspondent Node (CN) –End host to which MN is corresponding (eg. a web server)

48 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobile IP Support Services Agent Discovery –HA and FA broadcast their presence on each network to which they are attached Beacon messages via ICMP Router Discovery Protocol (IRDP) –MN listens for advertisement and then initiates registration Registration –When MN is away, it registers its COA with its HA Typically through the FA with strongest signal –Registration control messages are sent via UDP to well known port Encapsulation – just like standard IP only with COA Decapsulation – again, just like standard IP

49 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents IPv6 Mobile IP –3.2.1 Introduction to Mobile IP –3.2.2 Operations of Mobile IP –3.2.3 Problems with Mobile IP –3.2.4 Mobility in IPv6

50 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobile IP Operation A MN listens for agent advertisement and then initiates registration –If responding agent is the HA, then mobile IP is not necessary After receiving the registration request from a MN, the HA acknowledges and registration is complete –Registration happens as often as MN changes networks HA intercepts all packets destined for MN –This is simple unless sending application is on or near the same network as the MN –HA masquerades as MN –There is a specific lifetime for service before a MN must re-register –There is also a de-registration process with HA if an MN returns home

51 现代通信新技术导论 第三章 IPv6 and Mobile IP Registration Process

52 现代通信新技术导论 第三章 IPv6 and Mobile IP Tables Maintained on Routers Mobility Binding Table –Maintained on HA of MN –Maps MN’s home address with its current COA Visitor List –Maintained on FA serving an MN –Maps MN’s home address to its MAC address and HA address

53 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobile IP Operation HA then encapsulates all packets addressed to MN and forwards them to FA –IP tunneling FA decapsulates all packets addressed to MN and forwards them via hardware address (learned as part of registration process) NOTE that the MN can perform FA functions if it acquires an IP address eg. via DHCP Bidirectional communications require tunneling in each direction

54 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobile IP Tunneling

55 现代通信新技术导论 第三章 IPv6 and Mobile IP Security in Mobile IP Authentication can be performed by all parties –Only authentication between MN and HA is required –Keyed MD5 is the default Replay protection –Timestamps are mandatory –Random numbers on request reply packets are optional HA and FA do not have to share any security information

56 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents IPv6 Mobile IP –3.2.1 Introduction to Mobile IP –3.2.2 Operations of Mobile IP –3.2.3 Problems with Mobile IP –3.2.4 Mobility in IPv6

57 现代通信新技术导论 第三章 IPv6 and Mobile IP Problems with Mobile IP Suboptimal “triangle” routing –What if MN is in same subnetwork as the node to which it is communicating and HA is on the other side of the world? It would be nice if we could directly route packets –Solution: Let the CN know the COA of MN Then the CN can create its own tunnel to MN CN must be equipped with software to enable it to learn the COA Initiated by HA who notifies CN via “binding update” Binding table can become stale

58 现代通信新技术导论 第三章 IPv6 and Mobile IP Other Mobile IP Problems Single HA model is fragile –Possible solution – have multiple HA Frequent reports to HA if MN is moving –Possible solution – support of FA clustering Security –Connection hijacking, snooping… Many open research questions

59 现代通信新技术导论 第三章 IPv6 and Mobile IP Main Contents IPv6 Mobile IP –3.2.1 Introduction to Mobile IP –3.2.2 Operations of Mobile IP –3.2.3 Problems with Mobile IP –3.2.4 Mobility in IPv6

60 现代通信新技术导论 第三章 IPv6 and Mobile IP Mobility in IPv6 Route Optimization is a fundamental part of Mobile IPv6 –Mobile IPv4 it is an optional set of extensions that may not be supported by all nodes Foreign Agents are not needed in Mobile IPv6 –MNs can function in any location without the services of any special router in that location Security –Nodes are expected to employ strong authentication and encryption Other details…

61 现代通信新技术导论 第三章 IPv6 and Mobile IP A Brief Review IPv6 –Revolution from IPv4 Address space, routing information –IPv6 address Address format, special addresses, anycast and unicast address –IPv6 header Header format, next header/header extention –Address allocation –IPv6 in China CERNET2

62 现代通信新技术导论 第三章 IPv6 and Mobile IP A Brief Review Mobile IP –IP to solve the problem of mobility –Mobile IP entities MN, HA, FA, COA, CN –Support services Agent discovery, registration, encapsulation, decapsulation –Operations of Mobile IP Listen, registration, encapsulate, forward, decapsulate, forward –Problems with Mobile IP Triangle routing, single HA, frequent report, security –Mobility in IPv6


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