ExhibitYour ISP is announcing a default route to both R1 and R2.

The BGP attribute that you would use to forward all Internet traffic through the R1 device is the  local preference 1 .

The local preference is an attribute that is used within an autonomous system (AS) and exchanged between iBGP routers 1 .  It is used to select an exit point from the AS 1 .  The path with the highest local preference is preferred 1 .  By setting a higher local preference for the routes received from R1, you can make R1 the preferred exit point for all Internet traffic 1 .