Refer to the graphic.

Host A is communicating with the server. What will be the source MAC address of the frames
received by Host A from the server?

A.
the MAC address of router interface e0

B.
the MAC address of router interface e1

C.
the MAC address of the server network interface

D.
the MAC address of host A

Explanation:
Whereas switches can only examine and forward packets based on the contents of the MAC
header, routers can look further into the packet to discover the network for which a packet is
destined. Routers make forwarding decisions based on the packet’s network-layer header (such
as an IPX header or IP header). These network-layer headers contain source and destination
network addresses. Local devices address packets to the router’s MAC address in the MAC
header. After receiving the packets, the router must perform the following steps:

1. Check the incoming packet for corruption, and remove the MAC header . The router checks the
packet for MAC-layer errors. The router then strips off the MAC header and examines the networklayer header to determine what to do with the packet.
2. Examine the age of the packet. The router must ensure that the packet has not come too far to
be forwarded. For example, IPX headers contain a hop count. By default, 15 hops is the maximum
number of hops (or routers) that a packet can cross. If a packet has a hop count of 15, the router
discards the packet. IP headers contain a Time to Live (TTL) value. Unlike the IPX hop count,
which increments as the packet is forwarded through each router, the IP TTL value decrements as
the IP packet is forwarded through each router. If an IP packet has a TTL value of 1, the router
discards the packet. A router cannot decrement the TTL value to 1 and then forward the packet.
3. Determine the route to the destination. Routers maintain a routing table that lists available
networks, the direction to the desired network (the outgoing interface number), and the distance to
those networks. After determining which direction to forward the packet, the router must build a
new header. (If you want to read the IP routing tables on a Windows 95/98 workstation, type
ROUTE PRINT in the DOS box.)
4. Build the new MAC header and forward the packet. Finally, the router builds a new MAC header
for the packet. The MAC header includes the router’s MAC address and the final destination’s
MAC address or the MAC address of the next router in the path.