A company uses Routers R1 and R2 to connect to ISP1 and ISP2, respectively, with Routers
I1 and I2 used at the ISPs. R1 peers with I1 and R2; R2 peers with I2 and R1. R1 and R2 do
not share a common subnet, relying on other routers internal to the Enterprise for IP
connectivity between the two routers. Which of the following could be used to prevent
potential routing loops in this design? (Choose 2)

A.
Using an iBGP mesh inside the Enterprise core

B.
Configuring default routes in the Enterprise pointing to both R1 and R2

C.
Redistributing BGP routes into the Enterprise IGP

D.
Tunneling the packets for the iBGP connection between R1 and R2

Explanation:
The Enterprise core routers need to know which exit point (R1 or R2) is best; the correct
answers supply those routes to the routers internal to the company. Note that redistribution
from BGP into the IGP is not recommended, but it does defeat this particular problem.