Consider the arrangement of learning bridges shown in Figure 3.38. Assuming all are initially empty, give the forwarding tables for each of the bridges B1-B4 after the following transmissions:
Figure 3.38
¦ A sends to C.
¦ C sends to A.
¦ D sends to C.
Identify ports with the unique neighbor reached directly from that port; that is, the ports for B1 are to be labelled "A" and "B2."