CCNA思科网络技术学院教程-第19章_深入理解TCP.ppt

第19章深入理解TCP 主要内容 描述TCP IP如何保证任何互联网间的通信 19 1TCP IP协议集 Host Internet TCP IP Host TCP IP协议栈 7 6 5 4 3 2 4 3 Application Presentation Session Transport Network DataLink Physical 1 Application Transport Internet NetworkInterface OSI TCP IP 19 2应用层协议 Usedbytherouter Application Transport Internet DataLink Physical FileTransfer TFTP FTP E Mail SMTPRemoteLogin Telnet rlogin NetworkManagement SNMP NameManagement DNS 19 3传输层协议 TransmissionControlProtocol TCP UserDatagramProtocol UDP Application Transport Internet DataLink Physical Connection OrientedConnectionless 1 TCP数据段格式 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 Nosequenceoracknowledgmentfields 2 UDPSegmentFormat Sourceport 16 Destinationport 16 Length 16 Data ifany 1 Bit0 Bit15 Bit16 Bit31 Checksum 16 8Bytes 3 PortNumbers TCP PortNumbers FTP TransportLayer TELNET DNS SNMP TFTP SMTP UDP ApplicationLayer 21 23 25 53 69 161 RIP 520 TCP端口号 SourcePort Dest Port HostA 1028 23 SP DP HostZ TelnetZ Dest port 23 SendpackettomyTelnetapplication SendSYN seq 100ctl SYN SYNreceived HostA HostB 4 TCPThreeWayHandshake OpenConnection SendSYN seq 100ctl SYN SYNreceived SendSYN ACK seq 300ack 101ctl syn ack HostA HostB SYNreceived TCPThreeWayHandshake OpenConnection SendSYN seq 100ctl SYN SYNreceived SendSYN ACK seq 300ack 101ctl syn ack Established seq 101ack 301ctl ack HostA HostB SYNreceived TCPThreeWayHandshake OpenConnection 5 TCPSimpleAcknowledgment Windowsize 1 Sender Receiver TCPSimpleAcknowledgment Windowsize 1 Sender Receiver Send1 Receive1 TCPSimpleAcknowledgment Windowsize 1 Sender Receiver Send1 Receive1 ReceiveACK2 SendACK2 TCPSimpleAcknowledgment Windowsize 1 Sender Receiver Send1 Receive1 ReceiveACK2 SendACK2 Send2 Receive2 TCPSimpleAcknowledgment Windowsize 1 Sender Receiver Send1 Receive1 ReceiveACK2 SendACK2 Send2 Receive2 ReceiveACK3 SendACK3 TCPSimpleAcknowledgment Windowsize 1 Sender Receiver Send1 Receive1 ReceiveACK2 SendACK2 Send2 Receive2 ReceiveACK3 SendACK3 Send3 Receive3 Windowsize 1 Sender Receiver Send1 Receive1 ReceiveACK2 SendACK2 Send2 Receive2 ReceiveACK3 SendACK3 Send3 Receive3 ReceiveACK4 SendACK4 TCPSimpleAcknowledgment TCPSequenceandAcknowledgmentNumbers SourcePort Dest Port Sequence Acknowledgement Source Dest Seq Ack 1028 23 10 1 Ijustsent 10 TCPSequenceandAcknowledgmentNumbers Ijustgot 10 nowIneed 11 SourcePort Dest Port Sequence Acknowledgement 1028 23 Source Dest 10 Seq 1 Ack 1028 23 Source Dest 11 Seq 1 Ack Ijustsent 10 TCPSequenceandAcknowledgmentNumbers SourcePort Dest Port Sequence Acknowledgement 1028 23 Source Dest 11 Seq 2 Ack 1028 23 Source Dest 10 Seq 1 Ack 1028 23 Source Dest 11 Seq 1 Ack Ijustgot 10 nowIneed 11 Ijustsent 11 TCPSequenceandAcknowledgmentNumbers SourcePort Dest Port Sequence Acknowledgement 1028 23 Source Dest 11 Seq 2 Ack 1028 23 Source Dest 10 Seq 1 Ack 1028 23 Source Dest 11 Seq 1 Ack 1028 23 Source Dest 12 Seq 2 Ack Ijustgot 11 nowIneed 12 Ijustsent 11 6 TCPWindowing Sender Receiver TCPWindowing Windowsize 3Send2 Sender Receiver Windowsize 3Send1 Windowsize 3Send3 Windowsize 3Send2 TCPWindowing Sender Windowsize 3Send1 Windowsize 3Send3 ACK3Windowsize 2 Packet3isDropped Receiver Windowsize 3Send2 TCPWindowing Sender Windowsize 3Send1 Windowsize 3Send3 ACK3Windowsize 2 Packet3isDropped Windowsize 3Send4 Windowsize 3Send3 Receiver Windowsize 3Send2 TCPWindowing Sender Windowsize 3Send1 Windowsize 3Send3 ACK3Windowsize 2 Packet3isDropped Windowsize 3Send4 Windowsize 3Send3 ACK5Windowsize 2 Receiver 19 3InternetLayerOverview OSInetworklayercorrespondstotheTCP IPinternetlayer InternetProtocol IP InternetControlMessageProtocol ICMP AddressResolutionProtocol ARP ReverseAddressResolutionProtocol RARP Application Transport Internet DataLink Physical 1 IPDatagram 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 Determinesdestinationupper layerprotocol 2 ProtocolField TransportLayer InternetLayer TCP UDP ProtocolNumbers IP 17 6 3 InternetControlMessageProtocol Application Transport Internet DataLink Physical DestinationUnreachableEcho Ping Other ICMP 1 4 AddressResolutionProtocol 172 16 3 1 172 16 3 2 IP 172 16 3 2 IneedtheEthernetaddressof176 16 3 2 AddressResolutionProtocol 172 16 3 1 172 16 3 2 IP 172 16 3 2 AddressResolutionProtocol 172 16 3 1 IP 172 16 3 2Ethernet 0800 0020 1111 172 16 3 2 IP 172 16 3 2 AddressResolutionProtocol MapIPEthernetLocalARP 172 16 3 1 IP 172 16 3 2Ethernet 0800 0020 1111 172 16 3 2 IP 172 16 3 2 5 ReverseARP Ethernet 0800 0020 1111IP WhatismyIPaddress ReverseARP Ethernet 0800 0020 1111IP WhatismyIPaddress Iheardthatbroadcast YourIPaddressis172 16 3 25 ReverseARP Ethernet 0800 0020 1111IP 172 16