How can I setup a static route to be a backup in case of a failure on an IGRP route. Attempting to add the static route with a higher metric results in nothing being added to the routing table.
You could test this with a more specific route if you would like to just test your backup path.
Lets say you have a 192.168.3.0/24 route that IGRP has in it's routing table with a next hop of your primary link. If you make your static for just 1 host "ip route 192.168.3.200 255.255.255.255 105 then traffic for this host would travel across your backup link and you would see this in your routing table. Now you'd need to force this over to your backup for the return path or it would come back over your primary link, assuming that your routing is now symetrical.
Hope this helps,
adding a static route with higher AD works fine. You could not see it in routing table if major route active. When it fails the backup route will be active and be added to the table automatically.