Dual ISP Failover on Cisco Router

Fig 1: Dual ISP Failover

Dual ISP Failover on Cisco Router Configurations

!         

interface GigabitEthernet0/2

 description Secondary-WAN

 ip address x.x.x.x x.x.x.x

 ip nat outside

 ip virtual-reassembly in

 duplex auto

 speed auto

!       

interface GigabitEthernet0/1

 description Primary-WAN

 ip address x.x.x.x x.x.x.x

 ip nat outside

 ip virtual-reassembly in

 duplex auto

 speed auto

!           

interface GigabitEthernet0/0

 description LAN-Side

 no ip address

 duplex auto

 speed auto

!         

interface GigabitEthernet0/0.160

 description LAN-Phase

 encapsulation dot1Q 160

 ip address 172.16.23.1 255.255.255.0

 ip nat inside

 ip virtual-reassembly in

!         

interface GigabitEthernet0/0.260

 encapsulation dot1Q 260

 ip address 172.16.24.1 255.255.255.0

 ip nat inside

 ip virtual-reassembly in

 ip policy route-map SEC

!         

no ip http server

no ip http secure-server

!

track 8 ip sla 1 reachability

!

ip sla 1

 icmp-echo x.x.x.x source-ip x.x.x.x

ip sla schedule 1 life forever start-time now

!         

ip nat inside source route-map SEC interface GigabitEthernet0/2 overload

ip nat inside source route-map PRI interface GigabitEthernet0/1 overload

ip route 0.0.0.0 0.0.0.0 x.x.x.x track 8

ip route 0.0.0.0 0.0.0.0 x.x.x.x 10

ip route 0.0.0.0 0.0.0.0 x.x.x.x name Secondary

ip route 0.0.0.0 0.0.0.0 x.x.x.x name Primary

!         

access-list 100 permit ip 172.16.24.0 0.0.0.255 any

route-map SEC permit 10

 match ip address 100

 match interface GigabitEthernet0/2

 set ip default next-hop x.x.x.x

!         

access-list 101 permit ip 172.16.23.0 0.0.0.255 any

route-map PRI permit 10

 match ip address 101

 match interface GigabitEthernet0/1

 set ip default next-hop x.x.x.x

!                          

control-plane   

!         

end