PacketTracer網(wǎng)絡地址轉(zhuǎn)換NAT配置實驗

1、網(wǎng)絡地址轉(zhuǎn)換NAT配置一、實驗目標· 理解NAT網(wǎng)絡地址轉(zhuǎn)換的原理及功能；· 掌握靜態(tài)NAT的配置，實現(xiàn)局域網(wǎng)訪問互聯(lián)網(wǎng)；二、實驗背景公司欲發(fā)布WWW服務，現(xiàn)要求將內(nèi)網(wǎng)Web服務器IP地址映射為全局IP地址，實現(xiàn)外部網(wǎng)絡可訪問公司內(nèi)部Web服務器。三、技術原理· 網(wǎng)絡地址轉(zhuǎn)換NAT（Network Address Translation），被廣泛應用于各種類型Internet接入方式和各種類型的網(wǎng)絡中。原因很簡單，NAT不僅完美解決了IP地址不足的問題，而且還能夠有效地避免來自網(wǎng)絡外部的攻擊，隱藏并保護網(wǎng)絡內(nèi)部的計算機。· 默認情況下，內(nèi)部IP地址是無法

2、被路由到外網(wǎng)的，內(nèi)部主機.1要與外部internet通信，IP包到達NAT路由器時，IP包頭的源地址被替換成一個合法的外網(wǎng)IP，并在NAT轉(zhuǎn)換表中保存這條記錄。當外部主機發(fā)送一個應答到內(nèi)網(wǎng)時，NAT路由器收到后，查看當前NAT轉(zhuǎn)換表，用替換掉這個外網(wǎng)地址。· NAT將網(wǎng)絡劃分為內(nèi)部網(wǎng)絡和外部網(wǎng)絡兩部分，局域網(wǎng)主機利用NAT訪問網(wǎng)絡時，是將局域網(wǎng)內(nèi)部的本地地址轉(zhuǎn)換為全局地址（互聯(lián)網(wǎng)合法的IP地址）后轉(zhuǎn)發(fā)數(shù)據(jù)包。· NAT分為兩種類型：NAT（網(wǎng)絡地址轉(zhuǎn)換）和NAPT（網(wǎng)絡端口地址轉(zhuǎn)換IP地址對應一個全局地址）。· 靜態(tài)NAT：實現(xiàn)內(nèi)部

3、地址與外部地址一對一的映射。現(xiàn)實中，一般都用于服務器；· 動態(tài)NAT：定義一個地址池，自動映射，也是一對一的?，F(xiàn)實中，用得比較少；· NAPT：使用不同的端口來映射多個內(nèi)網(wǎng)IP地址到一個指定的外網(wǎng)IP地址，多對一。四、實驗步驟實驗拓撲1、R1為公司出口路由器，其與外部路由之間通過V.35電纜串口連接，DCE端連接在R2上，配置其時鐘頻率為64000；2、配置PC機、服務器及路由器接口IP地址；3、在各路由器上配置靜態(tài)路由協(xié)議，讓PC間能相互ping通；4、在R1上配置靜態(tài)NAT；5、在R1上定義內(nèi)外部網(wǎng)絡接口；6、驗證主機之間的互通性。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 /配置到網(wǎng)段的靜態(tài)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 /配置內(nèi)網(wǎng)到外網(wǎng)的靜態(tài)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