路由器双出口负载分担并NAT及互为备份.doc

思科路由器双WAN口负载分担并NAT及互为备份说明：客户接入ISP1及ISP2，内部有4 个网段分别是：/24/24/240/24正常模式为和两个网段优先走ISP1，和两个网段优先走ISP2。当IPS1线路中断时（即使R3接IPS1的接口是UP）和两个网段会自动转到ISP2，ISP2中断时同亦。下面是拓扑图，及各台设备的配置文档，在GNS3上模拟测试成功。（在网络上一直是伸手党，现在也分享下自己的经验，有不当之处还请指教，谢谢）分别在R1、R2均配置loopback 0 /32为测试对象,R3为边界路由器，配置最多放在最后R1R1#sh runBuilding configuration.Current configuration : 761 bytes!version 12.4service timestamps debug datetime msecservice timestamps log datetime msecno service password-encryption!hostname R1!boot-start-markerboot-end-marker!no aaa new-model!ip cefno ip domain lookup!interface Loopback0 ip address 55!interface FastEthernet0/0 ip address 48 duplex auto speed auto!interface FastEthernet0/1 no ip address shutdown duplex auto speed auto!ip route 48 !no ip http serverno ip http secure-server!control-plane!gatekeeper shutdown!line con 0 exec-timeout 0 0 logging synchronous stopbits 1line aux 0 stopbits 1line vty 0 4!endR2R2#sh runBuilding configuration.Current configuration : 761 bytes!version 12.4service timestamps debug datetime msecservice timestamps log datetime msecno service password-encryption!hostname R2!boot-start-markerboot-end-marker!no aaa new-model!ip cefno ip domain lookup!interface Loopback0 ip address 55!interface FastEthernet0/0 ip address 48 duplex auto speed auto!interface FastEthernet0/1 no ip address shutdown duplex auto speed auto!ip route 48 !no ip http serverno ip http secure-servercontrol-plane!gatekeeper shutdown!line con 0 exec-timeout 0 0 logging synchronous stopbits 1line aux 0 stopbits 1line vty 0 4!endR4R4#SH RUNBuilding configuration.Current configuration : 755 bytes!version 12.4service timestamps debug datetime msecservice timestamps log datetime msecno service password-encryption!hostname R4!boot-start-markerboot-end-marker!no aaa new-model!ip cefno ip domain lookup! ! !interface Loopback0 ip address 0 !interface FastEthernet0/0 ip address 0 duplex auto speed auto!interface FastEthernet0/1 no ip address shutdown duplex auto speed auto!ip route !no ip http serverno ip http secure-server!control-plane! !gatekeeper shutdown!line con 0 exec-timeout 0 0 logging synchronous stopbits 1line aux 0 stopbits 1line vty 0 4!endR5R5#SH RUNBuilding configuration.Current configuration : 757 bytes!version 12.4service timestamps debug datetime msecservice timestamps log datetime msecno service password-encryption!hostname R5!boot-start-markerboot-end-marker!no aaa new-model!ip cefno ip domain lookup! ! !interface Loopback0 ip address 0 !interface FastEthernet0/0 ip address 0 duplex auto speed auto!interface FastEthernet0/1 no ip address shutdown duplex auto speed auto!ip route 54!no ip http serverno ip http secure-server!control-plane! !gatekeeper shutdown!line con 0 exec-timeout 0 0 logging synchronous stopbits 1line aux 0 stopbits 1line vty 0 4!endR6R6#SH RUNBuilding configuration.Current configuration : 1548 bytes!version 12.4service timestamps debug datetime msecservice timestamps log datetime msecno service password-encryption!hostname R6!boot-start-markerboot-end-marker!no aaa new-model!resource policy!memory-size iomem 5ip cef! no ip domain lookup! ! !interface FastEthernet0/0 no ip address shutdown duplex auto speed auto!interface FastEthernet0/1 no ip address shutdown duplex auto speed auto!interface FastEthernet1/0 switchport mode trunk!interface FastEthernet1/1!interface FastEthernet1/2!interface FastEthernet1/3!interface FastEthernet1/4 switchport access vlan 10!interface FastEthernet1/5 switchport access vlan 20!interface FastEthernet1/6!interface FastEthernet1/7!interface FastEthernet1/8!interface FastEthernet1/9!interface FastEthernet1/10!interface FastEthernet1/11!interface FastEthernet1/12!interface FastEthernet1/13!interface FastEthernet1/14! interface FastEthernet1/15!interface Vlan1 no ip address!interface Vlan10 ip address 54 !interface Vlan20 ip address 54 !ip route ip route 0ip route 0!no ip http serverno ip http secure-server! !control-plane!line con 0 exec-timeout 0 0 logging synchronousline aux 0line vty 0 4!webvpn context Default_context ssl authenticate verify all ! no inservice!endR6#R3R3#SH RUNBuilding configuration.Current configuration : 2739 bytes!version 12.4service timestamps debug datetime msecservice timestamps log datetime msecno service password-encryption!hostname R3!boot-start-markerboot-end-marker!no aaa new-model!ip cefno ip domain lookup!ip sla monitor 1 type echo protocol ipIcmpEcho source-interface FastEthernet0/0 frequency 10ip sla monitor schedule 1 life forever start-time nowip sla monitor 2 type echo protocol ipIcmpEcho source-interface FastEthernet0/1 frequency 10ip sla monitor schedule 2 life forever start-time now!track 1 rtr 1 reachability!track 2 rtr 2 reachability! !interface FastEthernet0/0 ip address 48 ip nat outside ip virtual-reassembly duplex auto speed auto!interface FastEthernet0/1 ip address 48 ip nat outside ip virtual-reassembly duplex auto speed auto!interface FastEthernet1/0 no ip address shutdown duplex auto speed auto!interface FastEthernet1/1 no ip address shutdown duplex auto speed auto!interface FastEthernet2/0 no ip address duplex full!interface FastEthernet2/0.10 encapsulation dot1Q 10 ip address ip nat inside ip virtual-reassembly ip policy route-map test!ip route ip route ip route 54ip route 54ip route 54!no ip http serverno ip http secure-server!ip nat inside source route-map 1 interface FastEthernet0/0 overloadip nat inside source route-map 2 interface FastEthernet0/1 overloadip nat inside source route-map 3 interface FastEthernet0/1 overloadip nat inside source route-map 4 interface FastEthernet0/0 overload!access-list 10 permit 55access-list 10 permit 55access-list 20 permit 55a