Q&A: LAN

QUESTION 4:

The Certkiller corporate LAN consists of one large flat network. You decide to
segment this LAN into two separate networks with a router. What will be the affect
of this change.
A. The number of broadcast domains will be decreased.
B. It will make the broadcasting of traffic between domains more efficient between
segments.
C. It will increase the number of collisions.
D. It will prevent segment 1's broadcasts from getting to segment 2.
E. It will connect segment 1's broadcasts to segment 2.


Answer: D
Explanation
A router does not forward broadcast traffic. It therefore breaks up a broadcast domain,
reducing unnecessary network traffic. Broadcasts from one segment will not be seen on
the other segment.
Incorrect Answers:
A. This will actually increase the number of broadcast domains from one to two.
B. All link level traffic from segment one to segment two will now need to be routed
between the two interfaces of the router. Although this will reduce the traffic on the LAN
links, it does also provide a less efficient transport between the segments.
C. Since the network size is effectively cut into half, the number of collisions should
decrease dramatically.
E. Broadcasts from one segment will be completely hidden from the other segment.


QUESTION 5:

Which of the following are benefits of segmenting a network with a router. (Select
all that apply)
A. Broadcasts are not forwarded across the router.
B. All broadcasts are completely eliminated.
C. Adding a router to the network decreases latency.
D. Filtering can occur based on Layer 3 information.
E. Routers are more efficient than switches and will process the data more quickly.
F. None of the above.

Answer: A, D
Explanation
Routers do not forward broadcast messages and therefore breaks up a broadcast domain.
In addition, routers can be used to filter network information with the use of access lists.
Incorrect Answers:
B. Broadcasts will still be present on the LAN segments. They will be reduced, because
routers will block broadcasts from one network to the other.
C. Adding routers, or hops, to any network will actually increase the latency.
E. The switching process is faster than the routing process. Since routers must do a layer
3 destination based lookup in order to reach destinations, they will process data more
slowly than switches.