Part 1: Chapter 3 - Fundamentals of WANs and IP Routing

Question 1

Which of the following fields in the HDLC header used by Cisco routers does Cisco
add, beyond the ISO standard HDLC?
a. Flag
b. Type
c. Address
d. FCS

Question 2

Two routers, R1 and R2, connect using an Ethernet over MPLS service. The service
provides point-to-point service between these two routers only, as a Layer 2 Ethernet
service. Which of the following are the most likely to be true about this WAN?
(Choose two answers.)
a. R1 will connect to a physical Ethernet link, with the other end of the cable connected
to R2.
b. R1 will connect to a physical Ethernet link, with the other end of the cable connected
to a device at the WAN service provider point of presence.
c. R1 will forward data-link frames to R2 using an HDLC header/trailer.
d. R1 will forward data-link frames to R2 using an Ethernet header/trailer.

Question 3

Imagine a network with two routers that are connected with a point-to-point HDLC
serial link. Each router has an Ethernet, with PC1 sharing the Ethernet with Router1
and PC2 sharing the Ethernet with Router2. When PC1 sends data to PC2, which of
the following is true?
a. Router1 strips the Ethernet header and trailer off the frame received from PC1,
never to be used again.
b. Router1 encapsulates the Ethernet frame inside an HDLC header and sends the
frame to Router2, which extracts the Ethernet frame for forwarding to PC2.
c. Router1 strips the Ethernet header and trailer off the frame received from PC1,
which is exactly re-created by Router2 before forwarding data to PC2.
d. Router1 removes the Ethernet, IP, and TCP headers and rebuilds the appropriate
headers before forwarding the packet to Router2.

Question 4

Which of the following does a router normally use when making a decision about
routing TCP/IP packets?
a. Destination MAC address
b. Source MAC address
c. Destination IP address
d. Source IP address
e. Destination MAC and IP addresses

Question 5

Which of the following are true about a LAN-connected TCP/IP host and its IP routing
(forwarding) choices?
a. The host always sends packets to its default gateway.
b. The host never sends packets to its default gateway.
c. The host sends packets to its default gateway if the destination IP address is in a
different subnet than the host.
d. The host sends packets to its default gateway if the destination IP address is in the
same subnet as the host.

Question 6

Which of the following are functions of a routing protocol? (Choose two answers.)
a. Advertising known routes to neighboring routers
b. Learning routes for subnets directly connected to the router
c. Learning routes and putting those routes into the routing table for routes advertised
to the router by its neighboring routers
d. Forwarding IP packets based on a packet’s destination IP address

Question 7

A company implements a TCP/IP network, with PC1 sitting on an Ethernet LAN.
Which of the following protocols and features requires PC1 to learn information from
some other server device?
a. ARP
b. ping
c. DNS
d. None of these answers is correct.