第二章 TCPIP协议栈

第二章TCP/IP协议栈,本章目标,通过本章的学习，您应该掌握以下内容:掌握TCP/IP分层模型掌握三次握手过程理解OSI和TCP/IP模型的区别和联系,早期的协议族全球范围,TCP/IP介绍,主机,Internet,TCP/IP,主机,TCP/IP协议族,7,6,5,4,3,2,5,4,3,2,应用层,表示层,会话层,传输层,网络层,数据链路层,物理层,1,应用层,主机到主机层,Internet层,1,网络接入层,应用层概述,*路由器使用,应用层,主机到主机层,Internet层,文件传输-TFTP*-FTP*-NFSE-Mail-SMTP远程登陆-Telnet*-rlogin*网络管理-SNMP*名称管理-DNS*,网络接入层,主机到主机层概述,TransmissionControlProtocol(TCP)UserDatagramProtocol(UDP),应用层,主机到主机层,Internet层,网络接入层,面向连接非面向连接,TCP数据格式,Sourceport(16),Destinationport(16),Sequencenumber(32),Headerlength(4),Acknowledgementnumber(32),Reserved(6),Codebits(6),Window(16),Checksum(16),Urgent(16),Options(0or32ifany),Data(varies),20Bytes,Bit0,Bit15,Bit16,Bit31,端口号,TCP,端口号,FTP,传输层,TELNET,DNS,SNMP,TFTP,SMTP,UDP,应用层,21,23,25,53,69,161,RIP,520,TCP端口号,源端口,目标端口,HostA,1028,23,SP,DP,HostZ,TelnetZ,目标端口=23.,发送SYN(seq=100ctl=SYN),接收SYN,HostA,HostB,TCP三次握手,发送SYN(seq=100ctl=SYN),接收SYN,发送SYN,ACK(seq=300ack=101ctl=syn,ack),HostA,HostB,接收SYN,TCP三次握手,发送SYN(seq=100ctl=SYN),接收SYN,发送SYN,ACK(seq=300ack=101ctl=syn,ack),建立会话(seq=101ack=301ctl=ack),HostA,HostB,接收SYN,TCP三次握手,TCP连接建立,TCP简单确认,滑动窗口=1,发送方,接收方,TCP简单确认,滑动窗口=1,发送方,接收方,发送1,接收1,TCP简单确认,滑动窗口=1,发送方,接收方,发送1,接收1,接收ACK2,发送ACK2,TCP简单确认,滑动窗口=1,发送方,接收方,发送1,接收1,接收ACK2,发送ACK2,发送2,接收2,TCP简单确认,滑动窗口=1,发送方,接收方,发送1,接收1,接收ACK2,发送ACK2,发送2,接收2,接收ACK3,发送ACK3,TCP简单确认,滑动窗口=1,发送方,接收方,发送1,接收1,接收ACK2,发送ACK2,发送2,接收2,接收ACK3,发送ACK3,发送3,接收3,滑动窗口=1,发送方,接收方,发送1,接收1,接收ACK2,发送ACK2,发送2,接收2,接收ACK3,发送ACK3,发送3,接收3,接收ACK4,发送ACK4,TCP简单确认,TCP顺序号和确认号,源端口,目标端口,顺序号#,确认号#,Source,Dest.,Seq.,Ack.,1028,23,10,1,我发送#10.,TCP顺序号和确认号,我已收到#10,现在我需要#11.,源端口,目标端口,顺序号#,确认号#,1028,23,Source,Dest.,10,Seq.,1,Ack.,1028,23,Source,Dest.,11,Seq.,1,Ack.,我发送#10.,TCP顺序号和确认号,源端口,目标端口,顺序号#,确认号#,1028,23,Source,Dest.,11,Seq.,2,Ack.,1028,23,Source,Dest.,10,Seq.,1,Ack.,1028,23,Source,Dest.,11,Seq.,1,Ack.,我已收到#10,现在我需要#11.,我发送#10.,TCP顺序号和确认号,源端口,目标端口,顺序号#,确认号#,Source,Dest.,10,Seq.,1,Ack.,我已收到#11,现在我需要#12.,我发送#11,Source,Dest.,Seq.,Ack.,1028,23,11,2,1028,23,Source,Dest.,1,Seq.,11,Ack.,23,1028,Source,Dest.,Seq.,Ack.,23,1028,2,12,TCP窗口,发送方,接收方,TCP窗口,Windowsize=3Send2,发送方,接收方,Windowsize=3Send1,Windowsize=3Send3,Windowsize=3Send2,TCP窗口,发送方,Windowsize=3Send1,Windowsize=3Send3,ACK3Windowsize=2,数据3被丢弃,接收方,Windowsize=3Send2,TCP窗口,发送方,Windowsize=3Send1,Windowsize=3Send3,ACK3Windowsize=2,数据3被丢弃,Windowsize=3Send4,Windowsize=3Send3,接收方,Windowsize=3Send2,TCP窗口,发送方,Windowsize=3Send1,Windowsize=3Send3,ACK3Windowsize=2,数据3被丢弃,Windowsize=3Send4,Windowsize=3Send3,ACK5Windowsize=2,接收方,没有顺序号和确认号,UDP数据格式,Sourceport(16),Destinationport(16),Length(16),Data(ifany),1,Bit0,Bit15,Bit16,Bit31,Checksum(16),8Bytes,Internet层概述,OSI网络层对应的是TCP/IP的internet层,InternetProtocol(IP)InternetControlMessageProtocol(ICMP)AddressResolutionProtocol(ARP)ReverseAddressResolutionProtocol(RARP),应用层,主机到主机层,Internet层,网络接入层,IP数据,Version(4),DestinationIPAddress(32),Options(0or32ifany),Data(variesifany),1,Bit0,Bit15,Bit16,Bit31,HeaderLength(4),Priority&TypeofService(8),TotalLength(16),Identification(16),Flags(3),Fragmentoffset(13),Timetolive(8),Protocol(8),Headerchecksum(16),SourceIPAddress(32),20Bytes,决定上层协议,协议域,TransportLayer,InternetLayer,TCP,UDP,ProtocolNumbers,IP,17,6,ICMP协议,Application,Transport,Internet,NetworkAccess,DestinationUnreachableEcho(Ping)Other,ICMP,1,ARP协议,,,IP:=?,我需要知道的物理地址.,ARP协议,,,IP:=?,ARP协议,,IP:Ethernet:0800.0020.1111,,IP:=?,ARP协议,映射IPEthernetLocalARP,,IP:Ethernet:0800.0020.1111,,IP:=?,RARP协议,Ethernet:0800.0020.1111IP=?,我的地址是多少？,RARP协议,Ethernet:0800.0020.1111IP=?,我的地址是多少？,我听到了广播你的地址是5.,RARP协议,Ethernet:0800.0020.1111IP:5,Ethernet:0800.0020.1111IP=?,我的地址是多少？,我听到了广播你的地址是5.,RARP协议,映射EthernetIP,Ethernet:0800