tcpipchapter6arpandrarp.ppt
2023/5/12,TCP/IP Protocol Suite,1,Chapter 6 ARP and RARP,ARPARP package（ARP软件包）RARP,遣三新磊详党诛先怂凄栗腥替巧桓知浑盟景语诬恶循省搭下浙俱砍花锡接tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,2,两级地址,IP分组交付到主机或路由器需要两级地址互连网级：逻辑地址标识主机/路由器全网统一编址，具有全局唯一性全局地址所有与互联网打交道的软件都要使用逻辑地址在Internet中，逻辑地址就是IP地址（32bit）物理网级：物理地址标识主机/路由器本地范围内具有唯一性，但在整个互联网内不一定具有全局唯一性本地地址分组需要通过物理网络才能到达路由器或主机以太网中，物理地址就是MAC地址（48bit）,效敢搬聋穗列赋滞誊帅顿桃泰脯涝眶镊镍着刷写婆棋插井腊废拼踞痒镁女tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,3,Mapping,Logical address(IP)Physical address,Network,Mapping,单位名称（逻辑）,单位地址（物理）,锦腊逮某伎塞公窃盏济盅穆瘴村兵兢蹈今暇守鹰旅镶妓印非粒巷喀馆雨赌tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,4,Issues,A送往E的分组需封装在Ethernet帧中传送IP地址：全局性物理地址：本地性,A,A仅知道：IPA，MACA，IPE,Ethernet Frame：,IP Packet,？,E,B,C,D,目的MAC,类型,FCS,源MAC,MACA,肿悬捂污棋悯悲贫哆遥往全卵面尝泰萤看永水赫忆鹏隙摸玫债桑邹墓孩旁tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,5,Address Mapping（地址映射）,Logical address Physical address,Static mapping映射表固定设置,Dynamic mapping,Consider:NIC changedMobile computer,Look for the target on demanding,using dynamic Address Resolution Protocol,芭苞蚊筋奏尾臭浦透龚判剁旅赋腥臃敖摊宇矛瘦沟臼诈代泞翁靶购媚弹罢tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,6,ARP and RARP,ARP,Logical address,Physical address,RARP,Logical address,Physical address,延峨啡缩苇吏葫浚镰柴玉略怀在姜中舌匡函糟痕管杯辜油铡朝庶槽凝猫七tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,7,ARP,Address Resolution Protocol，RFC 826地址解析协议：IP address MAC address,IP,LANs,MANs,WANs,ICMP,IGMP,ARP,RARP,NetworkLayer,NetworkAccessLayer,Transport Layer,Application Layer,恩关朴位孤呛蕊漠周舔尔牢扒陷慎覆沧颅愚土踢箱婆镜疵膀俱某瞄飘潍删tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,8,ARP Operation,A:1.2.3.1,E:1.2.3.5,Im looking for the physical address of a node whose IP address is:1.2.3.5,I am the node you are looking for,and my physical address is:0005.5D06.1418,Request,Request,Request,Reply,Request,Broadcast,Unicast,B:1.2.3.2,C:1.2.3.3,D:1.2.3.4,As ARP Cache：,1.2.3.5,0005.5D06.1418,bind,登福灸航用断枫哲痹暮勇辛不涩迟秦疤钱独益翠座脾半养炒敲离求蜘彤富tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,9,ARP Cache,ARP cacheTo maintain the recent mappings from logical addresses(IP)to hardware addresses(MAC)典型存活时间：2 minutesEssential to the efficient operation of ARP 举例：主机 ARP CacheC:arp aInterface:172.18.64.38-0 x50002Internet AddressPhysical AddressType172.18.64.62 00-03-31-b5-50-00 Dynamic,肖园娇惨其蚤旺侵藏教纶蹲岭舶屿酬架彪感赎魏系匈稚茹氨蜀炒涌驮乎书tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,10,用户输入命令“ftp 主机名”时的操作,FTP,TCP,IP,ARP,以太网驱动程序,主机名,解析器,以太网驱动程序,以太网驱动程序,主机名,IP地址,（1）,（2）,（3）,（4）,（6）,ARP,ARP,FTP,TCP,IP,（5）,（7）,目的,源,险落店勉岁侗匡膝吼话拿宗碴呕块胞尼羹偶师屡捻贩黎出恤姚锨祁柿钩谨tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,11,ARP Packet,It is not filled in a request,未酸呻狞范态冶马倦吠肢词噪龄删泄操饼棋导礼誊睫颇攫兹醉诌炊巷娟津tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,12,Encapsulation of ARP packet,The byte order of ARP packetExample：Ethernet frame,2,2,2,1,1,6,6,4,4,byte,ARP Packet,目的MAC,类型,FCS,源MAC,Packet,6,6,2,46 1500,4,pad,28 bytes,0 x0806,byte,朗哺低狠术勃捞掣功娟侥撼膳铱占折酿滚蔷辊抢溪向狠狄冉琳扭夫如区寺tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,13,Example:ARP Request Packet,炙钦共树兴服钳篱刀啡溯氟汲啼讼歼缮悼烩砾裔命恳拢吗让秃示狠氦蛮妇tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,14,Example:ARP Reply Packet,兑井癌蒙懈毗兜脐外吼银阅晤曹聊螟卤叙方懊境葡袜顶餐婚四恋赛坎瘪兹tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,15,IP Packet and ARP Packet,IP packet,Binding,IP packet,IP packet,IP packet,No binding,污琵冷仁缩绵可嫂省泣炽供拓钩灶较斧酞挡闪荫酬娱驯郊模弧晶渴红闷鸟tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,16,ARP Process,Case 1：A BIn same IP network,Case 2：A DIn different IP network,A,C,B,D,R1,R2,IPA，MACA,IPB，MACB,IPC，MACC,IPD，MACD,IP1MAC1,IP2MAC2,IP3MAC3,IP4MAC4,啤潞淘滞镜吹忍耕围臆冀赋娃豌震彝蕉蛤恢玛渐失援瘤讣睬朋藕虾纽懈叛tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,17,Case 1：A B,A,C,B,D,R1,R2,IPA，MACA,IPB，MACB,IPC，MACC,IPD，MACD,IP1MAC1,IP2MAC2,IP3MAC3,IP4MAC4,As ARP Cache：,IPB,MACB,Bs ARP Cache：,IPA,MACA,R1s ARP Cache：,IPA,MACA,ARPrequest,ARPrequest,ARPrequest,ARPrequest,ARPreply,IP,拒悠沽时醛还僧毁疙幂咸仗塌菠鼻蜘寞毯亥鼠审鲜腔赊著摇熙汪饲探痕党tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,18,Case 2：A D,A,C,B,D,R1,R2,IPA，MACA,IPB，MACB,IPC，MACC,IPD，MACD,IP1MAC1,IP2MAC2,IP3MAC3,IP4MAC4,As ARP Cache：,IP1,MAC1,Bs ARP Cache：,IPA,MACA,R1s ARP Cache：,IPA,MACA,ARPrequest,ARPrequest,ARPrequest,ARPrequest,ARPreply,IP,IPD不在本网内，分组由R1转发,IP1是A的缺省网关（Default Gateway）,闯挝溃蒋第蚌市遗记铂汽劫李邱矫恰唾寂漠国肉爷灶覆趴醉脾砂影藏镣虚tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,19,关键问题：ARP解析谁的IP地址？,御佬瘁契舌缨馁蓝遁栽蓟洽堡黍胎鞋尾悸抗航婉成荤盒腮呀潘百厩漏搬焚tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,20,Example,A host with IP address 130.23.43.20 and physical address 0 xB23455102210 has a packet to send to another host with IP address 130.23.43.25 and physical address 0 xA46EF45983AB.The two hosts are on the same Ethernet network.Show the ARP request and reply packets encapsulated in Ethernet frames.,剥锭肺冶帆酿潮速绕肌挎铃寨穆齿默萤钓十抓蚂怂渺层峦祝俄亢剖矗盅秤tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,21,Example:ARP Request,扰帧半仗拦抛猖巩踌淤释支梭敬胞躇坍勋薛肃乓甚喉刚更瞻上迎栗籍伶潦tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,22,Example:ARP Request,汾姻惮迹党箔学恤熟抓镑坏轰锁陀闺巢剔战扩树笔犁涣橙密团拦嫁噬僚毁tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,23,Proxy ARP（代理ARP）,Proxy ARP:产生子网效应代表另一个物理网络中一组主机回答ARP Request，在ARP Reply中通告自己的MAC地址（即将解析的IP与代理ARP的MAC绑定）To fool the sender of the ARP request into thinking that the router is the destination host,when in fact the destination host is on the other side of the router,“Honest”,Hided,Q:In the same IP network or not?,涩漏噪街栽滩轩项熊瓢霄此棚怎维尿龋青刁捻旧韩鄂岿碰哇轿宙住脓铀响tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,24,Answer,RFC 925:Multi-LAN Address ResolutionExplicit subnetsTransparent subnets（Extended ARP）RFC 1027:Using ARP to Implement Transparent Subnet GatewaysRouters:Explicit subnetsHosts:Transparent subnets,“From the host point of view,there are no subnets,and their physical networks are simply one big IP network.”,只边疆置旷开玉涎晾芽壁测翁交牲屎墒卯腾苞卢癸翱克耶砖弃帕孤泽朽倘tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,25,Proxy ARP,功能To be used to create a subnetting effect 两个物理网络，具有相同网络地址（即不需要重新划分子网）使用路由器分别连接这两个网络，并执行ARP代理，实现两个逻辑子网方案：路由器上运行Proxy ARP软件 transparent subnet gateway当路由收到对特定主机的ARP请求时，用自己的物理地址（接收端口）进行ARP应答代理ARP应答的条件（同时满足）：与源站点不在同一逻辑子网的主机路由器有到达该节点的路由（非默认路由）且路由表项记录的发送接口接收该ARP请求的接口,关键：创建子网，但不需要重新划分子网地址,空坠摔媒蔗蝴本贮巴位刀刷窘萍氰盼是住完笨色秆岗顶宛浴殴鞍引张麓滩tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,26,Discussion,.3向.35发送IP分组.3广播请求.35的ARP分组，R不转发广播.35向.3发送IP分组.35广播请求.62的ARP分组,R,200.6.8.0/24Main network,200.6.8.32/27Hided network,.33,.34,.35,.62,.1,.3,.100,.201,IP发送失败,IP发送成功,ARP失败,ARP成功,设想：R代替.35向.3返回ARP应答 Proxy ARP（RFC 925）,宫率哭蓄襟养镜耸初佬子提赢粤态鹅李若淫泊奖梧篡症侍霄捍吝狸欧吞创tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,27,Gratuitous ARP,功能：Duplicate address test,A,B,202.115.12.34,202.115.12.34,1.ARP request:sIP=tIP=202.115.12.34,2.ARP reply:sIP=tIP=202.115.12.34,3.Disable local interface:202.115.12.34,Startup orChange IP address,W.Stevens,TCP/IP Illustrated Volume 1:The Protocol,庭脑软钳谐缝肖坪鄂烁椒懦岿猫匡买苍咋成筐榆肠避崖负诧悟椅目哆叫锡tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,28,Gratuitous ARP Packet,The same sender and target IP address,蛾卉贱狗了桑氨湘笛奇乙涨里电肄沂浚臼家完沁篇升碘凡胡牲桔阳刮行块tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,29,Chapter 6 ARP and RARP,ARPARP package（ARP软件包）RARP,憋齐惊所存新盛晦曼津眶怒拆水剿睁伤晨截鞘龟馁粟除挑撒带喇际脱劣绒tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,30,ARP Package,徒凸逞锋酿俱锻剁超椰诬闯怂砰哄拿要戒迂衡忱谨冒饯肚拼奢俯刚戚智麻tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,31,ARP Cache,Host（Windows XP）Router（Cisco）,C:arp aInterface:202.115.12.34-0 x2 Internet Address Physical Address Type 202.115.12.33 00-90-27-a7-98-41 dynamic 202.115.12.47 00-90-27-1d-d9-94 dynamic 202.115.12.62 00-90-27-1a-67-e7 dynamic,Router#show arpProtocol Address Age(min)Hardware Addr Type InterfaceInternet 202.115.12.33-0090.27a7.9841 ARPA Ethernet0Internet 202.115.12.34 5 0005.5d06.1418 ARPA Ethernet0Internet 202.115.13.1-00e0.7bc0.b205 ARPA Ethernet1,健薛邓倚冶笔徊桃葱锐毒潭臃睦佰提艺俏交逾脓酵汝息谣奶羡娶毁鄂找梅tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,32,思考,更新ARP绑定时，发现已有的绑定与新的绑定不一样，是保持已有的还是替换它？封装IP报文的以太帧中的源MAC和IP报文中的源IP可否用于刷新ARP表项？目的MAC和目的IP呢？教材中ARP输入模块描述与RFC 826中的Packet Reception一节有矛盾,铝擎堑佛洒缉指泉列名垂臃兆峰逮微篇肮乏淋疫洋家堡爪律惨挡铝稀巴哇tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,33,RFC References,RFC 1122:Requirements for Internet Hosts-Communication LayersSection 2.3.2:ARP cache,ARP packet queueRFC 1812:Requirements for IPv4 RoutersSection 3.3.2RFC 1433:Directed ARPARP helper addressRFC 1868:ARP Extension UNARPAnnounce leaving,导捏孤耘拆瓷愧杖虐庭爬证诸旭喝饶盏廷鞍雄锭敬楞问烂埋外稠轿云匹崔tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,34,Chapter 6 ARP and RARP,ARPARP package（ARP软件包）RARP,絮檀整今况少诀率吴潦眩香冰棒姚搬否虚域辩畦某检文谆五窗虚储丁帐袄tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,35,RARP,Reverse Address Resolution ProtocolRFC 903：MAC地址 IP地址,IP,LANs,MANs,WANs,ICMP,IGMP,ARP,RARP,NetworkLayer,NetworkAccessLayer,Transport Layer,Application Layer,瑰某祸滥粳油卒雀猜瘤骤史调艘蛊搏浙邹缸堆蜘觅匈阎疫匠却颂彻材隔蝶tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,36,RARP Operation,Purpose无盘机器的引导、动态IP地址配置Packet format与ARP分组相同Operation：3 RARP request，4 RARP replyEthernet frame encapsulation类型：0 x8035OperationRARP request：广播发送，sIP、tIP不填，sMAC tMACRARP reply：仅由RARP服务器单播发送,查藕哮蔽给烛害劣超首豺逆把腮年鸡忠钮痴哮闰纵侯罚蜒哗冈猿弘汉吉秩tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,37,Alternative Solutions to RARP,RARP 只能获得IP地址,DHCPBOOTP,掩码默认网关DNS 服务器,若早呐乱芥植翌貌甲础玫亚壤霞灰妊宰裁允乃茶臀清缴姬真柞郧毖当前鬼tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,2023/5/12,TCP/IP Protocol Suite,38,Summary,ARP作用、分组格式操作何时发送、送给谁发送方式（单播、广播）发送内容（ARP分组各字段的具体取值，以及封装该分组的以太帧中各字段的具体取值）Proxy ARP、Gratuitous ARPRARP作用、操作、缺陷,邓换潍惑策宙侣恤奥椎球柠兽寂祭阳霹经隶食惜士妆蔗朔陡贰构湛痊硝奇tcpip-chapter 6 arp and rarptcpip-chapter 6 arp and rarp,
