[医学]原版CCNA教材-第3章TCPIP协议栈.ppt

第三章 TCP/IP协议栈,通过本章的学习，您应该掌握以下内容： 了解TCP/IP协议栈,各个分层的主要功能、IP协议的应用 掌握IP地址分类，子网掩码的作用，识别网络标识号、主机标识号，子网的数目 理解OSI和TCP/IP模型的区别和联系 掌握三次握手过程,本章目标,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,5,4,3,2,5,4,3,2,应用层,表达层,会话层,传输层,网络层,数据链路层,物理层,1,应用层,传输层,Internet层,数据链路层,物理层,1,应用层概述,应用层,传输层,Internet层,数据链路层,物理层,文件传输 - TFTP 69 - FTP 21/20 - NFS 2049 E-Mail - SMTP 25 远程登陆 - Telnet 23 - rlogin 网络管理 - SNMP 161 名称管理 - DNS 53,传输层概述,Transmission Control Protocol (TCP) User Datagram Protocol (UDP),应用层,传输层,Internet层,数据链路层,物理层,面向连接 非面向连接,TCP 数据格式,Source port (16),Destination port (16),Sequence number (32),Header length (4),Acknowledgement number (32),Reserved (6),Code bits (6),Window (16),Checksum (16),Urgent (16),Options (0 or 32 if any),Data (varies),20 Bytes,Bit 0,Bit 15,Bit 16,Bit 31,端口号,TCP,端口号,F T P,传输层,T E L N E T,D N S,S N M P,T F T P,S M T P,UDP,应用层,21,23,25,53,69,161,R I P,520,TCP 端口号,源端口,目标端口,Host A,1028,23,SP,DP,Host Z,Telnet Z,目标端口 = 23.,发送 SYN (seq=100 ctl=SYN),接收 SYN,Host A,Host B,TCP 三次握手,发送 SYN (seq=100 ctl=SYN),接收 SYN,发送 SYN+ACK (seq=300 ack=101 ctl=syn,ack),Host A,Host B,接收 SYN,TCP 三次握手,发送 SYN (seq=100 ctl=SYN),接收 SYN,发送 SYN+ACK (seq=300 ack=101 ctl=syn,ack),建立会话 (seq=101 ack=301 ctl=ack),Host A,Host B,接收 SYN,TCP 三次握手,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 ACK 2,发送 ACK 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 ACK 2,发送 ACK 2,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 ACK 2,发送 ACK 2,发送 2,接收 2,接收 ACK 3,发送 ACK 3,TCP 简单确认,滑动窗口 = 1,发送方,接收方,发送 1,接收 1,接收 ACK 2,发送 ACK 2,发送 2,接收 2,接收 ACK 3,发送 ACK 3,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 ACK 2,发送 ACK 2,发送 2,接收 2,接收 ACK 3,发送 ACK 3,发送 3,接收 3,接收 ACK 4,发送 ACK 4,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 #,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.,我已收到 #11, 现在我需要 #12.,我发送 #11,TCP 窗 口,发送方,接收方,TCP 窗 口,Window size = 3 Send 2,发送方,接收方,Window size = 3 Send 1,Window size = 3 Send 3,Window size = 3 Send 2,TCP 窗 口,发送方,Window size = 3 Send 1,Window size = 3 Send 3,ACK 3 Window size = 2,数据 3 被丢弃,接收方,Window size = 3 Send 2,TCP 窗 口,发送方,Window size = 3 Send 1,Window size = 3 Send 3,ACK 3 Window size = 2,数据 3 被丢弃,Window size = 3 Send 4,Window size = 3 Send 3,接收方,Window size = 3 Send 2,TCP 窗 口,发送方,Window size = 3 Send 1,Window size = 3 Send 3,ACK 3 Window size = 2,数据 3 被丢弃,Window size = 3 Send 4,Window size = 3 Send 3,ACK 5 Window size = 2,接收方,没有顺序号和确认号,UDP 数据格式,Source port (16),Destination port (16),Length (16),Data (if any),1,Bit 0,Bit 15,Bit 16,Bit 31,Checksum (16),8 Bytes,Internet 层概述,OSI 网络层对应的是TCP/IP的internet层,Internet Protocol (IP) Internet Control Message Protocol (ICMP) Address Resolution Protocol (ARP) Reverse Address Resolution Protocol (RARP),应用层,传输层,Internet层,数据链路层,物理层,IP 数据,Version (4),Destination IP Address (32),Options (0 or 32 if any),Data (varies if any),1,Bit 0,Bit 15,Bit 16,Bit 31,Header Length (4),Priority & Type of Service (8),Total Length (16),Identification (16),Flags (3),Fragment offset (13),Time to live (8),Protocol (8),Header checksum (16),Source IP Address (32),20 Bytes,决定上层协议,协议域,Transport Layer,Internet Layer,TCP,UDP,Protocol Numbers,IP,17,6,ICMP协议,Application,Transport,Internet,Data Link,Physical,Destination Unreachable Echo (Ping) Other,ICMP,1,互联网控制消息协议ICMP,通过ICMP协议，主机和路由器可以报告错误并交换相关的状态信息。在下列情况中，通常自动发送ICMP消息： IP数据报无法访问目标。 IP路由器（网关）无法按当前的传输速率转发数据报。 IP路由器将发送主机重定向为使用更好的到达目标的路。 ICMP协议的结构如图2-26所示。,ICMP协议的结构,ICMP协议的头结构,ICMP头结构比较简单，如表2-9所示。,ICMP数据报分析,使用Ping命令发送ICMP回应请求消息，使用Ping命令，可以检测网络或主机通讯故障并解决常见的TCP/IP连接问题。分析Ping指令的数据报，如图2-27所示。,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 IP Ethernet Local ARP,,IP: Ethernet: 0800.0020.1111,,IP: = ?,RARP协议,Ethernet: 0800.0020.1111 IP = ?,我的地址是多少？,RARP协议,Ethernet: 0800.0020.1111 IP = ?,我的地址是多少？,我听到了广播你的地址是 5.,RARP协议,Ethernet: 0800.0020.1111 IP: 5,Ethernet: 0800.0020.1111 IP = ?,我的地址是多少？,我听到了广播你的地址是 5.,RARP协议,映射 Ethernet IP,Ethernet: 0800.0020.1111 IP: 5,Ethernet: 0800.0020.1111 IP = ?,我的地址是多少？,我听到了广播你的地址是 5.,断点连接需要确定的地址 路径选择,TCP/IP地址介绍,,,,,,,SA,DA,HDR,DATA,,,,,IP 地 址,255,255,255,255,Dotted Decimal,Maximum,Network,Host,32 bits,IP 地 址,255,255,255,255,Dotted Decimal,Maximum,Network,Host,128 64 32 16 8 4 2 1,11111111,11111111,11111111,11111111,Binary,32 bits,1,8,9,16,17,24,25,32,128 64 32 16 8 4 2 1,128 64 32 16 8 4 2 1,128 64 32 16 8 4 2 1,IP 地 址,255,255,255,255,Dotted Decimal,Maximum,Network,Host,128 64 32 16 8 4 2 1,11111111,11111111,11111111,11111111,10101100,00010000,01111010,11001100,Binary,32 bits,172,16,122,204,Example Decimal,Example Binary,1,8,9,16,17,24,25,32,128 64 32 16 8 4 2 1,128 64 32 16 8 4 2 1,128 64 32 16 8 4 2 1,Class A: Class B: Class C: Class D: 多址地址 Class E: 科研用,IP 地址分类,8 bits,8 bits,8 bits,8 bits,IP 地址分类,1,Class A:,Bits:,0NNNNNNN,Host,Host,Host,8,9,16,17,24,25,32,Range (1-126),1,Class B:,Bits:,10NNNNNN,Network,Host,Host,8,9,16,17,24,25,32,Range (128-191),1,Class C:,Bits:,110NNNNN,Network,Network,Host,8,9,16,17,24,25,32,Range (192-223),1,Class D:,Bits:,1110MMMM,Multicast Group,Multicast Group,Multicast Group,8,9,16,17,24,25,32,Range (224-239),主机地址,,0,2,,1,18,E1,172.16,12,12,网络,主机,.,.,网络,端口, ,E0 E1,路由表,,,E0,11111111,计算可用的主机地址,172 16 0 0,10101100,00010000,00000000,00000000,16 15 14 13 12 11 10 9,8 7 6 5 4 3 2 1,网络,主机,00000000,00000001,11111111,11111111,11111111,11111110,.,.,00000000,00000011,11111101,1,2,3,65534,65535,65536,-,.,2,65534,N,2N-2 = 216-2 = 65534,IP地址分类练习,地址,类别,网络,主机,,00,4,,6,20,IP地址分类练习 （答案）,地址,类别,网络,主机,,00,4,,6,20,A,B,C,C,B,Nonexistent,,,,,,,00,4,,6,网络 ,,不设子网的地址,,,,.,53,54,网络 ,设置子网的地址,,,,,子网地址,00,,60,,,00,50,E0,172.16,网络,网络,端口, ,E0 E1,新路由表,2,160,主机,.,.,,E1,子网地址,00,,60,,,00,50,,E0,E1,172.16,2,160,网络,主机,.,.,网络,端口, ,E0 E1,新路由表,子网,子网掩码,255,255,0,0,IP Address,Default Subnet Mask,8-bit Subnet Mask,Network,Host,Network,Host,Network,Subnet,Host,“/16” 表示子网掩码有16位.,“/24”表示子网掩码有24位.,11111111,11111111,00000000,00000000,十进制和二进制的转换,1 0 0 0 0 0 0 0 = 128 1 1 0 0 0 0 0 0 = 192 1 1 1 0 0 0 0 0 = 224 1 1 1 1 0 0 0 0 = 240 1 1 1 1 1 0 0 0 = 248 1 1 1 1 1 1 0 0 = 252 1 1 1 1 1 1 1 0 = 254 1 1 1 1 1 1 1 1 = 255,128 64 32 16 8 4 2 1,16,网络,主机,172,0,0,10101100,11111111,10101100,00010000,11111111,00010000,00000000,00000000,10100000,00000000,00000000,缺省情况下子网未划分,00000010,缺省情况下的子网掩码,60,,网络号,扩展了8位地址的网络,利用子网掩码划分子网,16,网络,主机,60,,172,2,0,10101100,11111111,10101100,00010000,11111111,00010000,11111111,00000010,10100000,00000000,00000000,00000010,子网,网络号,128 192 224 240 248 252 254 255,利用子网掩码划分子网,网络,主机,60,92,10101100,11111111,10101100,00010000,11111111,00010000,11111111,00000010,10100000,11000000,10000000,00000010,子网,扩展了10位地址的网络,16,172,2,128,网络号,128 192 224 240 248 252 254 255,128 192 224 240 248 252 254 255,子网掩码练习,地址,子网掩码,类别,子网,0,0,2,,,,子网掩码练习（答案）,地址,子网掩码,类别,子网,0,0,2,,,,B,A,A,,,,广播地址,,,,,55 (Directed broadcast),55 (Local network broadcast),X,55 (All subnets broadcast),地址汇总示例,16,172,2,160,10101100,00010000,10100000,00000010,Host,Mask,Subnet,Broadcast,Last,First,60,92,4,1,地址汇总示例,10101100,11111111,00010000,11111111,11111111,10100000,11000000,00000010,Host,Mask,Subnet,Broadcast,Last,First,60,92,1,2,16,172,2,160,地址汇总示例,10101100,11111111,00010000,11111111,11111111,10100000,11000000,00000010,Host,Mask,Subnet,Broadcast,Last,First,60,92,1,2,3,7,16,172,2,160,地址汇总示例,10101100,11111111,00010000,11111111,11111111,10100000,11000000,10000000,00000010,Host,Mask,Subnet,Broadcast,Last,First,60,92,1,2,3,4,16,172,2,160,地址汇总示例,10101100,11111111,00010000,11111111,11111111,10100000,11000000,10000000,00000010,10111111,Host,Mask,Subnet,Broadcast,Last,First,60,92,1,2,3,4,5,6,16,172,2,160,地址汇总示例,10101100,11111111,00010000,11111111,11111111,10100000,11000000,10000000,00000010,10111111,10000001,Host,Mask,Subnet,Broadcast,Last,First,60,92,1,2,3,4,5,6,16,172,2,160,地址汇总示例,10101100,11111111,00010000,11111111,11111111,10100000,11000000,10000000,00000010,10111111,10000001,10111110,Host,Mask,Subnet,Broadcast,Last,First,60,92,1,2,3,4,5,6,7,16,172,2,160,地址汇总示例,10101100,11111111,10101100,00010000,11111111,00010000,11111111,00000010,10100000,11000000,10000000,00000010,10101100,00010000,00000010,10111111,10101100,00010000,00000010,10000001,10101100,00010000,00000010,10111110,Host,Mask,Subnet,Broadcast,Last,First,60,92,1,2,3,4,5,6,7,8,16,172,2,160,地址汇总示例,10101100,11111111,10101100,00010000,11111111,00010000,11111111,00000010,10100000,11000000,10000000,00000010,10101100,00010000,00000010,10111111,10101100,00010000,00000010,10000001,10101100,00010000,00000010,10111110,Host,Mask,Subnet,Broadcast,Last,First,60,92,28,91,29,90,1,2,3,4,5,6,7,8,9,16,172,2,160,划分子网路由器转发分组算法,1、从收到的数据报的首部提取目的IP地址D 2、先判断是否为直接交付。 3、若路由表中有目的地址为D的特定主机路由，则将数据报传送给路由表中所指明的下一跳路由器 4、对路由表中的每一行，将其中的子网掩码和D逐比特相“与”， 5、若路由表中有一个默认路由，则将数据报传送给路由表中所指明的默认路由器；否则，执行（6）。 6、报告转发分组出错。,IP Host Address: 21 Subnet Mask: ,Subnet Address = Host Addresses = 54 Broadcast Address = 55 Eight bits of subnetting,Network,Subnet,Host,10101100,00010000,00000010,11111111,21:,:,10101100,11111111,Subnet:,10101100,0001