Consider the network shown in Figure 4.56, in which horizontal lines represent transit providers and numbered vertical lines are inter provider links.
(a) How many routes to P could provider Q's BGP speakers receive?
(b) Suppose Q and P adopt the policy that outbound traffic is routed to the closest link to the destination's provider, thus minimizing their own cost. What paths will traffic from host A to host B and from host B to host A take?
(c) What could Q do to have the B-→A traffic use the closer link 1?
(d) What could Q do to have the B-→A traffic pass through R?
