conditionally originating default routes in OSPF

hello

let’s say you have a static route to your ISP:

ip route 80.0.0.1 255.255.255.255 192.168.0.1

and now you want to send down a default route based on the availability of the connection to this ISP.

here’s the config

ip route 80.0.0.1 255.255.255.255 192.168.0.1 track 1

ip sla 1

icmp-echo 192.168.0.1

freq 5

track 1 ip sla 1 reachability

ip prefix-list myispprefix permit 80.0.0.1/32

route-map isp1prefix permit 10

match ip address prefix-list myispprefix

router ospf 1

default-information-originate route-map isp1prefix

 

If you don’t have an ISP and you want to ”fake it”, you can use a fake route. e.g. 169.254.0.1 255.255.255.255 null0 track 1