用route-map实现双ISP接入

以下实验是从我前面发的实验中剥离出来的，希望对各位网友有所帮助 如拓扑所示，在实验室环境下，R5,R6,R7为CISCO2509路由器，和CISCO4000一起,一边模拟帧中继网络，一边用PPP chap认证，下面的局域网采用OSPF，均已配置成功，此来模拟两种不同的ISP接入，目前实验已经完成，成功的实现了线路冗余和负载均衡。 下面发下4000上的配置 r9#show run Building configuration... Current configuration : 1777 bytes ! version 12.1 no service single-slot-reload-enable service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname r9 ! ! username r7 password 0 123 ! ! ! ! ip subnet-zero ! ! ! ! ! ! interface Loopback0 ip address 9.9.9.9 255.255.255.0 ! interface Ethernet0 ip address 172.16.1.1 255.255.255.0 ip nat inside media-type 10BaseT ! interface Ethernet1 ip address 172.16.4.1 255.255.255.0 ip nat inside media-type 10BaseT ! interface Serial0 no ip address shutdown no fair-queue ! interface Serial1 ip address 172.16.2.1 255.255.255.0 ip nat outside encapsulation frame-relay ip policy route-map fuzai frame-relay map ip 172.16.2.2 100 broadcast frame-relay interface-dlci 100 ! interface Serial2 ip address 172.16.3.1 255.255.255.0 ip nat outside encapsulation ppp ip policy route-map fuzai shutdown ! interface Serial3 no ip address shutdown ! router ospf 1 log-adjacency-changes network 172.16.1.1 0.0.0.0 area 0 network 172.16.4.1 0.0.0.0 area 0 default-information originate ! ip nat inside source route-map isp1 interface Serial1 overload ip nat inside source route-map isp2 interface Serial2 overload ip classless ip route 0.0.0.0 0.0.0.0 172.16.3.2 ip route 0.0.0.0 0.0.0.0 172.16.2.2 no ip http server ! access-list 1 permit 192.168.3.0 0.0.0.255 access-list 1 permit 192.168.4.0 0.0.0.255 access-list 2 permit 192.168.3.0 access-list 3 permit 192.168.4.0 route-map isp2 permit 20 match ip address 1 ! route-map isp1 permit 20 match ip address 1 match interface Serial1 ! route-map fuzai permit 10 match ip address 2 set ip default next-hop 172.16.2.2 ! route-map fuzai permit 20 match ip address 3 set ip default next-hop 172.16.3.2 ! ! ! line con 0 logging synchronous line aux 0 line vty 0 4 ! end