Linux Routing (Backup Internet Connection)

[Scott Sharkey]

Hi All,

I have a site that uses RoadRunner as it's primary connection to the
internet, with a DSL Line which they want to use as a secondary,
backup connection.  Is there a simple way to set up a Linux
router/firewall that will auto-route between the two if the primary
is not working?  Do I need to run Zebra or something like that?

-Scott