Cisco backup - send traffic via 2 ISPs
Jump to navigation
Jump to search
Introduction
This is an generic example how to send traffics via different routes ISP1 or ISP2 depend on the source.
Design
------> VLAN10 > -------- ISP1 -------------
| |
| |
LAN --(VLAN 10 & 20)----- WAN router Internet
| |
| |
------> VLAN20 > -------- ISP2 -------------
Configuration
r1(config)#access-list 1 permit 192.168.1.0 0.0.0.255 !Creates ACL 1, which will filter out addresses for our first route map. r1(config)#access-list 2 permit 172.16.1.0 0.0.0.255 !Creates ACL 2, which will filter out addresses for our second route map. r1(config)#access-list 101 permit ip 192.168.1.0 0.0.0.255 172.16.1.0 0.0.0.255 !Creates an extended ACL, resulting in a filter based on both source and destination IP address. r1(config)#access-list 102 permit ip 172.16.1.0 0.0.0.255 192.168.1.0 0.0.0.255 !Creates an extended ACL, resulting in a filter based on both source and destination IP address. r1(config)#route-map ISP1 permit 10 !Creates a route map called ISP1. This route map will permit traffic based on subsequent criteria. A sequence number of 10 is assigned. r1(config-route-map)#match ip address 1 !Specifies the match criteria—match addresses filtered from ACL 1. r1(config-route-map)#set interface serial 0/0/0 !Specifies the set actions (what action is to be performed if the match criteria is met); in this case, forward packets out interface s0/0. r1(config-route-map)#exit r1(config)#route-map ISP2 permit 10 !Creates a route map called ISP2. r1(config-route-map)#match ip address 2 !Specifies the match criteria—match addresses filtered from ACL 2. r1(config-route-map)#set interface serial 0/0/1 !Specifies the set actions (what action is to be performed if the match criteria is met); in this case, forward packets out interface s0/1. r1(config-route-map)#exit r1(config)#route-map 192To172 permit 10 !Creates a route map named 192To172. This route map will permit traffic based on subsequent criteria. A sequence number of 10 is assigned. r1(config-route-map)#match ip address 101 !Specifies the match criteria—match addresses filtered from ACL 101. r1(config-route-map)#set interface fastethernet 0/1 !Specifies the set actions—forward packets out interface FastEthernet 0/1. r1(config-route-map)#exit r1(config)#route-map 172To192 permit 10 !Creates a route map named 172To192. r1(config-route-map)#match ip address 102 !Specifies the match criteria—match addresses filtered from ACL 102. r1(config-route-map)#set interface fastethernet 0/0 !Specifies the set actions—forward packets out interface FastEthernet 0/0. r1(config-route-map)#exit r1(config)#interface serial 0/0/0 !Moves to interface configuration mode. r1(config-if)#description link to ISP1 r1(config-if)#ip address 198.133.219.1 255.255.255.252 !Assigns an IP address and netmask. r1(config-if)#no shutdown r1(config)#interface serial 0/0/1 r1(config-if)#description link to ISP2 r1(config-if)#ip address 192.31.7.1 255.255.255.252 !Assigns an IP address and netmask. r1(config-if)#no shutdown r1(config)#interface fastethernet 0/0 !Moves to interface configuration mode to assign ROUTE-MAP POLICY r1(config-if)#ip address 192.168.1.1 255.255.255.0 !Configures an IP address and netmask. r1(config-if)#ip policy route-map ISP1 !Applies the route map named ISP1 to this interface. r1(config-if)#ip policy route-map 192To172 !Applies the route map named 192To172 to this interface. r1(config-if)#no shutdown r1(config-if)#exit r1(config)#interface fastethernet 0/1 !Moves to interface configuration mode. r1(config-if)#ip address 172.16.1.1 255.255.255.0 !Configures an IP address and netmask. r1(config-if)#ip policy route-map ISP2 !Applies the route map named ISP2 to this interface. r1(config-if)#ip policy route-map 172To192 !Applies the route map named 172To192 to this interface. r1(config-if)#no shutdown r1(config-if)#exit r1(config-if)#end