Trace the data path in Figure 9-26 from an Ethernet-attached node in VLAN 1 on Cat-A to an Ethernet-attached node in VLAN 2 on Cat-B. Why is this inefficient?
The traffic travels through the ELAN1 to the router where it is routed to ELAN2. It then travels across ELAN2 to reach the node on Cat-B. This is inefficient because: 1) the router might not be as fast as the ATM network and 2) the router was required to reassemble the cells back into a complete packet before the routing decision could be made. After the packet is routed, it has to again be segmented into cells.