We have a CISCO 800 series connected to 2 WAN channels, and 2 VLANs. The idea is to have VLAN1 always use WAN1 channel, and VLAN2 use WAN2 channel, but in case of connectivity failure switch to a working channel. Important to say that both WANs use DHCP-assigned IP addresses, so it's not possible to determine next-hop IP address etc.. Default gateways can change from time to time.
I got some problems with realizing this and will greatly appreciate your help:
First some config:
interface FastEthernet8 <---- WAN 2 ip address dhcp ip nat outside ip virtual-reassembly in duplex auto speed auto ! interface GigabitEthernet0 <----- WAN 1 ip address dhcp ip nat outside ip virtual-reassembly in duplex auto speed auto ! interface Vlan1 <---------- VLAN 1 description LAN interface ip address 192.168.244.1 255.255.255.0 ip nat inside ip virtual-reassembly in ip policy route-map VLAN1LAN ! interface Vlan2 <------- VLAN 2 ip address 192.168.243.1 255.255.255.0 ip nat inside ip virtual-reassembly in ip policy route-map VLAN2LAN !
Here are the route-maps and access-lists:
ip access-list extended LAN1 permit ip 192.168.244.0 0.0.0.255 any ! ip access-list extended LAN2 permit ip 192.168.243.0 0.0.0.255 any ! route-map VLAN2LAN permit 10 match ip address LAN2 set interface FastEthernet8 ! route-map VLAN1LAN permit 10 match ip address LAN1 set interface GigabitEthernet0 !
Also have this for NAT:
route-map VLAN1NAT permit 10 match interface GigabitEthernet0 ! route-map VLAN2NAT permit 10 match interface FastEthernet8 ! ip nat inside source route-map VLAN1NAT interface GigabitEthernet0 overload ip nat inside source route-map VLAN2NAT interface FastEthernet8 overload
This configuration works (VLAN1 <--nat---> WAN1 and VLAN2 <---nat---> WAN2) but does not solve the problem of channel breakdown switch.
So I implemented some sla and tracks:
track 10 ip sla 1 reachability delay down 20 up 20 ! track 20 ip sla 2 reachability delay down 20 up 20 ! ip sla 1 icmp-echo X.X.X.X source-interface GigabitEthernet0 threshold 500 timeout 500 frequency 5 ip sla schedule 1 life forever start-time now ip sla 2 icmp-echo Y.Y.Y.Y source-interface FastEthernet8 threshold 500 timeout 500 frequency 5 ip sla schedule 2 life forever start-time now
This all works (tracks show channel availabiility), but now how do I apply these tracks to PBRs. Since I do not use
next-hop, and use set interface there is no option to set a track. I would like to do smth like this:
route-map VLAN2LAN permit 10 <---- high priority match ip address LAN2 set interface FastEthernet8 track 2 ! route-map VLAN2LAN permit 30 <---- used when track 2 fails match ip address LAN2 set interface GigabitEthernet0 track 1 !