An ISP who has 2 sister companies want to take the benefits of the MPLS mesh system

[afaqzafar49]

An ISP company established MPLS with their different hops/routers (5 router participating MPLS systems) across Berlin. The company has two sister companies (A and B). Both the sister concerns want to take the benefits of the MPLS mesh system. Each sister concern has 4 branch offices and a Head Office where the data center is located.

As a network engineer, we have to connect all the offices of A & B to the MPLS system. We have to ensure that only HO of each company has internet access and all the traffic from branch offices will be forwarded to HO through the MPLS system in a secure way. At the same time, make sure that the routing tables of each company in MPLS are not exposed. I need help in terms of designing this scenario with some detail on implementation and configuration guide.  

[MHM Cisco World]

Friend simply, 

In all branch the default route will be toward HQ, from there in HQ config defualt route toward isp.

[afaqzafar49]

Thanks frnd. I got your point. but can you plz explain a little more, don't we need anything else? i was reading some articles, dont we need to implement MPBGP vpnv4 between isp and other sis companies HO's? do we need to configure any bgp between sites? or the only def route will do the work? plzzz explain a little more for my understanding. thanks.