第三章 IPv6 与移动 IP Chapter 3 IPv6 and Mobile IP

现代通信新技术导论

第三章 IPv6 与移动 IPChapter 3 IPv6 and Mobile IP

电控学院电子工程学科部司鹏搏综合楼 825 室[email protected]

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


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




• 3.2 Mobile IP


3.1.1 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




• 3.2 Mobile IP


3.1.2 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


3.1.2 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


IPv4

3.1.2 Solve the ProblemsExhaustion 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


3.1.2 Towards IPv6• Address extension and starting over

– 16 bytes = 3.4×1038 v.s. 4 bytes = 4.3×109 – Some technologies are mandatory

• Plug and play• End-to-end security (i.e., IPsec)

• At least 65536 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?




• 3.2 Mobile IP


3.1.3 IPv6 Address Format

FP = Format Prefix (= 001 for globally aggregated unicast addresses)TLA-ID = Top-level aggreation identifierRES = Reserved for future useNLA = Next-level aggregation identifierSLA-ID = Site-level aggregation identifierInterface ID = Interface identifier

Interface-IDFP TLA-ID Res NLA-ID SLA-ID

≥3 ≤13 8 24 16 64

128 bit

Public TopologySiteTopology Interface Identifier

Network Portion Node Portion


3.1.3 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 0-128 is placed after “/”– 3ffe:500/25

现代通信新技术导论第三章 IPv6 and Mobile IP0000 0000 Reserved

0000 0001 Unassigned

0000 001 Reserved for NSAP (non-IP addresses used by ISO)

0000 010 Reserved for IPX (non-IP addresses used by IPX)

0000 011 Unassigned

0000 1 Unassigned

0001 Unassigned

001 Unicast Address Space

010 Unassigned

011 Unassigned

100 Unassigned

101 Unassigned

110 Unassigned

1110 Unassigned

1111 0 Unassigned

1111 10 Unassigned

1111 110 Unassigned

1111 1110 0 Unassigned

1111 1110 10 Link Local Use addresses

1111 1110 11 Site Local Use addresses

1111 1111 Multicast addresses


3.1.3 Special Addresses• All zero

– Represents absence of an address• ::1

– Analogous to IPv4 loopback 127.0.0.1• 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


3.1.3 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


3.1.3 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)


3.1.3 Multicast Address Format

Group-ID11111111 flgs

8 4 112

128 bit

scope

4

First 3 bits set to 0Last bit defines address type:0 = Permanent (or well-known)1 = Locally assigned (or transient)

Defines address scope0 Reserved1 Node-local scope2 Link-local scope5 Site-local scope8 Organization local scopeE Global scopeF Reserved


3.1.3 Well-known Multicast AddressesIPv6 Well-known

multicast addressIPv4 Well-known

multicast addressMulticast Group

Node-local scopeFF01:0:0:0:0:0:0:1 224.0.0.1 All-nodes addressFF01:0:0:0:0:0:0:2 224.0.0.2 All-routers address

Link-local scopeFF02:0:0:0:0:0:0:1 224.0.0.1 All-nodes addressFF02:0:0:0:0:0:0:2 224.0.0.2 All-routers addressFF02:0:0:0:0:0:0:5 224.0.0.5 OSPFIGPFF02:0:0:0:0:0:0:6 224.0.0.6 OSPFIGP-DR‘sFF02:0:0:0:0:0:0:9 224.0.0.9 RIP routersFF02:0:0:0:0:0:0:D 224.0.0.13 All PIM routers

Site-local scopeFF05:0:0:0:0:0:0:2 224.0.0.2 All-routers address

Any valid scopeFF0X:0:0:0:0:0:0:101 224.0.1.1 Network time protocol

NTP


3.1.3 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”




• 3.2 Mobile IP


3.1.4 IPv4 vs. IPv6 Header Formats

Ver.6

Traffic class8 bits

Flow label20 bits

Payload Length16 bits

Next Hdr.8 bits

Hop Limit8 bits

Source Address128 bits

Destination Address128 bits

32 bits

Ver.4 HL Datagram LengthTOS

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

OptionsVariable bits

DataData


3.1.4 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?


3.1.4 IPv6 Extension Headers

IPv6 headerNH=TCP

TCP header + data

Routing headerNH=TCP

IPv6 headerNH=Routing

IPv6 headerNH=Routing

Routing headerNH=Fragment

Fragment headerNH=TCP

TCP header + data

TCP header + data


3.1.4 IPv6 Extension HeadersValue (Hexadecimal) Value (Decimal) Protocol / Extension Header

00 0 Hop-By-Hop Options Extension Header

01 1 ICMPv4

02 2 IGMPv4

04 4 IP in IP Encapsulation

06 6 TCP

08 8 EGP

11 17 UDP

29 41 IPv6

2B 43 Routing Extension Header

2C 44 Fragmentation Extension Header

2E 46 Resource Reservation Protocol (RSVP)

32 50 Encrypted Security Payload (ESP) Extension Header

33 51 Authentication Header (AH) Extension Header

3A 58 ICMPv6

3B 59 No Next Header

3C 60 Destination Options Extension Header


3.1.4 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

0 8 16 24 31

Next header Hd. Ext. Len 0 Segmnts left

1 – 24 addresses


3.1.4 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

0 8 16 29 31

next header reserved offset Mreserved

ID


3.1.4 Authentication Extension• Next header value: 51• Provides data integrity and authentication

0 31

next header Payload length reserved

Security Parameters Index (SPI)

Sequence Number Field

Authentication Data


3.1.4 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

Payload Data Padding

Padding Pad Length Next Header

Authentication Data




• 3.2 Mobile IP


3.1.5 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


3.1.5 EUI-64

00 90 27 17 fc 0f

00 90 27 17 fc 0f

ff fe

00 90 27 17 fc 0fff fe

02 90 27 17 fc 0fff fe

00000000

00000010

MAC Address

Add ff:fe

NOT (the 7th bit)

EUI-64 address




• 3.2 Mobile IP


3.1.6 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


3.1.6 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




• 3.2 Mobile IP


3.1.7 CERNET2 in China



3.1.7 IPv6 Address Allocation in CERNET2代码地址段所有单位BJ 2001:DA8:0200::/48 清华大学BJ 2001:DA8:0201::/48 北京大学BJ 2001:DA8:0202::/48 北京邮电大学BJ 2001:DA8:0203::/48 北航大学BJ 2001:DA8:0204::/48 北京理工大学BJ 2001:DA8:0205::/48 北京交通大学BJ 2001:DA8:0206::/48 北京城市学院BJ 2001:DA8:0207::/48 北京师范大学BJ 2001:DA8:0208::/48 北京科技大学BJ 2001:DA8:0209::/48 首都经济贸易大学BJ 2001:DA8:020A::/48 北方工业大学BJ 2001:DA8:020B::/48 国家计算机网络应急技术处理协调中心BJ 2001:DA8:020C::/48 华北电力大学 (北京 )BJ 2001:DA8:020D::/48 赛尔网络有限公司 IDC部门BJ 2001:DA8:020E::/48 中国传媒大学BJ 2001:DA8:020F::/48 北京外国语大学BJ 2001:DA8:0210::/48 北京机械工业学院BJ 2001:DA8:0211::/48 北京林业大学BJ 2001:DA8:0212::/48 北京信息工程学院BJ 2001:DA8:0213::/48 教育部科技发展中心BJ 2001:DA8:0214::/48 中国地质大学 (北京 )BJ 2001:DA8:0215::/48 北京邮电大学BJ 2001:DA8:0216::/48 北京工业大学BJ 2001:DA8:0217::/48 DRAGONLAB实验室BJ 2001:DA8:0218::/48 首都师范大学

代码地址段所有单位CD 2001:DA8:6000::/48 电子科技大学CHC 2001:DA8:B000::/48 吉林大学CHC 2001:DA8:B001::/48 东北电力学院CHQ 2001:DA8:C800::/48 重庆大学CHQ 2001:DA8:C801::/48 重庆交通大学CHS 2001:DA8:D000::/48 中南大学DLN 2001:DA8:A800::/48 大连理工大学DLN 2001:DA8:A801::/48 大连海事大学DLN 2001:DA8:A802::/48 大连轻工业学院GZ 2001:DA8:2000::/48 华南理工大学GZ 2001:DA8:2001::/48 广州市教育局HEF 2001:DA8:D800::/48 中国科技大学HEF 2001:DA8:D801::/48 解放军电子工程学院HEF 2001:DA8:D802::/48 安徽理工大学HEF 2001:DA8:D803::/48 安徽中医学院HEF 2001:DA8:D804::/48 皖南医学院HEF 2001:DA8:D805::/48 合肥工业大学HRB 2001:DA8:B800::/48 哈尔滨工业大学HRB 2001:DA8:B801::/48 哈尔滨工业大学HZH 2001:DA8:E000::/48 浙江大学HZH 2001:DA8:E001::/48 浙江工业大学HZH 2001:DA8:E002::/48 浙江大学宁波理工学院JNN 2001:DA8:7000::/48 山东大学JNN 2001:DA8:7001::/48 山东大学齐鲁软件学院JNN 2001:DA8:7002::/48 CERNET山东省网络中心


3.1.7 IPv6 Address Allocation in CERNET2代码地址段所有单位JNN 2001:DA8:7003::/48 山东大学威海分校JNN 2001:DA8:7004::/48 山东农业大学JNN 2001:DA8:7005::/48 济南大学JNN 2001:DA8:7006::/48 石油大学 (华东 )JNN 2001:DA8:7007::/48 石油大学 (华东 )青岛校区JNN 2001:DA8:7008::/48 山东理工大学JNN 2001:DA8:7009::/48 烟台大学JNN 2001:DA8:700A::/48 烟台师范学院JNN 2001:DA8:700B::/48 山东省计算中心JNN 2001:DA8:700C::/48 山东财政学院LZH 2001:DA8:C000::/48 兰州大学LZH 2001:DA8:C001::/48 甘肃省教育和科研计算机网LZH 2001:DA8:C002::/48 甘肃政法学院LZH 2001:DA8:C003::/48 西北师范大学NJ 2001:DA8:1000::/48 CERNET2核心节点 -南京NJ 2001:DA8:1001::/48 江苏省教育和科研计算机网NJ 2001:DA8:1002::/48 东南大学NJ 2001:DA8:1003::/48 南京师范大学NJ 2001:DA8:1004::/48 河海大学NJ 2001:DA8:1005::/48 南京农业大学NJ 2001:DA8:1006::/48 南京航空航天大学NJ 2001:DA8:1007::/48 南京大学NJ 2001:DA8:1008::/48 江苏工业学院NJ 2001:DA8:1009::/48 河海大学常州校区NJ 2001:DA8:100A::/48 苏州大学SH 2001:DA8:8000::/48 上海交通大学SH 2001:DA8:8001::/48 复旦大学SH 2001:DA8:8002::/48 同济大学SH 2001:DA8:8003::/48 上海交通大学 -上海城域网

代码地址段所有单位SH 2001:DA8:8004::/48 华东工业大学SH 2001:DA8:8005::/48 华东师范大学SH 2001:DA8:8006::/48 上海大学SH 2001:DA8:8007::/48 华东理工大学SH 2001:DA8:8008::/48 东华大学SH 2001:DA8:8009::/48 上海市教育委员会SH 2001:DA8:800A::/48 上海第二医科大学SH 2001:DA8:800B::/48 上海师范大学SH 2001:DA8:800C::/48 第二军医大学SH 2001:DA8:800D::/48 上海财经大学SH 2001:DA8:800E::/48 上海外国语大学SH 2001:DA8:800F::/48 上海建桥学院SY 2001:DA8:9000::/48 东北大学SY 2001:DA8:9001::/48 辽宁大学TJN 2001:DA8:A000::/48 天津大学TJN 2001:DA8:A001::/48 天津理工大学TJN 2001:DA8:A002::/48 天津医科大学WH 2001:DA8:3000::/48 华中科技大学WH 2001:DA8:3001::/48 华中师范大学WH 2001:DA8:3002::/48 华中农业大学XA 2001:DA8:4000::/48 西安交通大学XMN 2001:DA8:E800::/48 厦门大学ZHZ 2001:DA8:5000::/48 郑州大学ZHZ 2001:DA8:5001::/48 河南财经学院ZHZ 2001:DA8:5002::/48 解放军信息工程大学ZHZ 2001:DA8:5003::/48 河南省财经学校ZHZ 2001:DA8:5004::/48 河南省教育科研网ZHZ 2001:DA8:5005::/48 郑州大学西亚斯国际学院


Main Contents• 3.1 IPv6• 3.2 Mobile IP



3.2.1 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


3.2.1 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


3.2.1 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?


3.2.1 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


3.2.1 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


3.2.1 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)


3.2.1 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


Main Contents• IPv6• Mobile IP



3.2.2 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


3.2.2 Registration Process


3.2.2 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


3.2.2 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


3.2.2 Mobile IP Tunneling


3.2.2 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


3.2.2 Main Contents• IPv6• Mobile IP



3.2.3 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


3.2.3 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


Main Contents• IPv6• Mobile IP



3.2.4 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…


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


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

Documents

第三章 IPv6 与移动 IP Chapter 3 IPv6 and Mobile IP