We have multiple sites connecting to an MPLS cloud. All sites are running BGP. The two main locations, site A and site B, have an Internet connection. The three branch locations, sites C, D and E, are without their own local Internet connection and are getting access through a site that does.

We would like to be able to have branch site C access the Internet through main site A, and branch sites D and E access the Internet through main site B. Please see the attached image to clarify this scenario.

Right now main site B is known on the MPLS cloud as the primary route to the Internet, and main site A is known as a secondary route to the Internet. This setup is working fine, we would just like to implement this new level of complexity. I must concede that it has been told to me that this solution cannot be implemented. I would be completely satisfied if someone knows of a way to make this work, but I would be able to move forward with confirmation that it cannot be done.

Thanks.