PacketTracer网络地址转换NAT配置实验

1、网络地址转换NAT配置一、实验目标· 理解NAT网络地址转换的原理及功能；· 掌握静态NAT的配置，实现局域网访问互联网；二、实验背景公司欲发布WWW服务，现要求将内网Web服务器IP地址映射为全局IP地址，实现外部网络可访问公司内部Web服务器。三、技术原理· 网络地址转换NAT（Network Address Translation），被广泛应用于各种类型Internet接入方式和各种类型的网络中。原因很简单，NAT不仅完美解决了IP地址不足的问题，而且还能够有效地避免来自网络外部的攻击，隐藏并保护网络内部的计算机。· 默认情况下，内部IP地址是无法

2、被路由到外网的，内部主机.1要与外部internet通信，IP包到达NAT路由器时，IP包头的源地址被替换成一个合法的外网IP，并在NAT转换表中保存这条记录。当外部主机发送一个应答到内网时，NAT路由器收到后，查看当前NAT转换表，用替换掉这个外网地址。· NAT将网络划分为内部网络和外部网络两部分，局域网主机利用NAT访问网络时，是将局域网内部的本地地址转换为全局地址（互联网合法的IP地址）后转发数据包。· NAT分为两种类型：NAT（网络地址转换）和NAPT（网络端口地址转换IP地址对应一个全局地址）。· 静态NAT：实现内部

3、地址与外部地址一对一的映射。现实中，一般都用于服务器；· 动态NAT：定义一个地址池，自动映射，也是一对一的。现实中，用得比较少；· NAPT：使用不同的端口来映射多个内网IP地址到一个指定的外网IP地址，多对一。四、实验步骤实验拓扑1、R1为公司出口路由器，其与外部路由之间通过V.35电缆串口连接，DCE端连接在R2上，配置其时钟频率为64000；2、配置PC机、服务器及路由器接口IP地址；3、在各路由器上配置静态路由协议，让PC间能相互ping通；4、在R1上配置静态NAT；5、在R1上定义内外部网络接口；6、验证主机之间的互通性。R1:Router>enRout

4、er#conf tEnter configuration commands, one per line. End with CNTL/Z.Router(config)#hostname R1R1(config)#int fa0/0R1(config-if)#ip add R1(config-if)#no shut%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, ch

5、anged state to upR1(config-if)#exitR1(config)#int s2/0R1(config-if)#ip add R1(config-if)#no shut%LINK-5-CHANGED: Interface Serial2/0, changed state to downR1(config-if)#%LINK-5-CHANGED: Interface Serial2/0, changed state to up%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2/0, ch

6、anged state to upR1(config-if)#R1(config-if)#R1(config-if)#exitR1(config)#ip route /配置到网段的静态路由R1(config)#endR1#%SYS-5-CONFIG_I: Configured from console by consoleR1#show ip routeCodes:C - connected, S - static, I - IGRP, R - RIP, M - mobile, B BGPD - EIGRP, EX - EIGRP external, O - OSPF, IA

7、 - OSPF inter areaN1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2E1 - OSPF external type 1, E2 - OSPF external type 2, E EGPi - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area* - candidate default, U - per-user static route, o ODRP - periodic downloaded static rou

8、teGateway of last resort is not setC is directly connected, FastEthernet0/0C is directly connected, Serial2/0S 1/0 via R1#R1#R1#conf tEnter configuration commands, one per line. End with CNTL/Z.R1(config)#int fa0/0R1(config-if)#? arp Set arp type (arpa, probe, snap) or timeout bandwidth Set

9、 bandwidth informational parameter cdp CDP interface subcommands crypto Encryption/Decryption commands custom-queue-list Assign a custom queue list to an interface delay Specify interface throughput delay description Interface specific description duplex Configure duplex operation. exit Exit from in

10、terface configuration mode fair-queue Enable Fair Queuing on an Interface hold-queue Set hold queue depth ip Interface Internet Protocol config commands mac-address Manually set interface MAC address mtu Set the interface Maximum Transmission Unit (MTU) no Negate a command or set its defaults priori

11、ty-group Assign a priority group to an interface service-policy Configure QoS Service Policy shutdown Shutdown the selected interface speed Configure speed operation. tx-ring-limit Configure PA level transmit ring limit zone-member Apply zone nameR1(config-if)#ip ? access-group Specify access contro

12、l for packets address Set the IP address of an interface hello-interval Configures IP-EIGRP hello interval helper-address Specify a destination address for UDP broadcasts inspect Apply inspect name ips Create IPS rule mtu Set IP Maximum Transmission Unit nat NAT interface commands ospf OSPF interfac

13、e commands split-horizon Perform split horizon summary-address Perform address summarization virtual-reassembly Virtual ReassemblyR1(config-if)#ip nat ? inside Inside interface for address translation outside Outside interface for address translationR1(config-if)#ip nat inside ? <cr>R1(config-

14、if)#ip nat inside R1(config-if)#exitR1(config)#int s2/0R1(config-if)#ip nat outside ? <cr>R1(config-if)#ip nat outside R1(config-if)#exitR1(config)#R1#R1#R1#conf tEnter configuration commands, one per line. End with CNTL/Z.R1(config)#ip ? access-list Named access-list default-network Flags net

15、works as candidates for default routes dhcp Configure DHCP server and relay parameters domain IP DNS Resolver domain-lookup Enable IP Domain Name System hostname translation domain-name Define the default domain name forward-protocol Controls forwarding of physical and directed IP broadcasts host Ad

16、d an entry to the ip hostname table name-server Specify address of name server to use nat NAT configuration commands route Establish static routes tcp Global TCP parametersR1(config)#ip nat ? inside Inside address translation outside Outside address translation pool Define pool of addressesR1(config

17、)#ip nat inside ? source Source address translationR1(config)#ip nat inside source ? list Specify access list describing local addresses static Specify static local->global mappingR1(config)#ip nat inside source static ? Inside local IP address tcp Transmission Control Protocol udp User Datagram

18、ProtocolR1(config)#ip nat inside source static ? Inside global IP addressR1(config)#ip nat inside source static ? <cr>R1(config)#ip nat inside source static /配置内网到外网的静态NAT映射R1(config)#endR1#%SYS-5-CONFIG_I: Configured from console by consoleR1#show ip nat ? statistics Translation statistics tr

19、anslations Translation entriesR1#show ip nat translations Pro Inside global Inside local Outside local Outside global- - -R1#R1#show ip nat translations Pro Inside global Inside local Outside local Outside global- - -tcp :80 :80 :1025 :1025R1#R1#show running-con

20、fig Building configuration.Current configuration : 753 bytes!version 12.2no service timestamps log datetime msecno service timestamps debug datetime msecno service password-encryption!hostname R1!.!interface FastEthernet0/0 ip address ip nat inside duplex auto speed auto!interface Fast

21、Ethernet1/0 no ip address duplex auto speed auto shutdown!interface Serial2/0 ip address ip nat outside!interface Serial3/0 no ip address shutdown!interface FastEthernet4/0 no ip address shutdown!interface FastEthernet5/0 no ip address shutdown!ip nat inside source static ip classlessi

22、p route !.!line con 0line vty 0 4 login!endR1#R2:Router>Router>enRouter#conf tEnter configuration commands, one per line. End with CNTL/Z.Router(config)#hostname R2R2(config)#int fa0/0R2(config-if)#ip add R2(config-if)#no shut%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up%LINE

23、PROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to upR2(config-if)#exitR2(config)#int s2/0R2(config-if)#ip add R2(config-if)#no shut%LINK-5-CHANGED: Interface Serial2/0, changed state to upR2(config-if)#clock rate 64000R2(config-if)#%LINEPROTO-5-UPDOWN: Line protocol on Int

24、erface Serial2/0, changed state to upR2(config-if)#R2(config-if)#R2(config-if)#exitR2(config)#ip route R2(config)#endR2#%SYS-5-CONFIG_I: Configured from console by consoleR2#show ip routeCodes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OS