Chapter 1 Review Questions Flashcards
How many collison and broadcast domains does the device shown here have?
1 collision, 1 broadcast. The device shown is a hub and hubs place all ports in the same broadcast domain and the same collision domain.
With respect to the OSI model, what addresses does a packet have?
A packet contains IP addresses. The contents of a protocol data unit (PDU) depend on the PDU because they are created in a specific order and their contents are based on that order. A packet will contain IP addresses but not MAC addresses because MAC addresses are not present until the PDU becomes a frame.
You are the Cisco administrator for your company. A new branch office is opening and you are selecting the necessary hardware to support the network. There will be two groups of computers, each organized by department. The Sales group computers will be assigned IP addresses ranging from 192.168.1.2 to 192.168.1.50. The Accounting group will be assigned IP addresses ranging from 10.0.0.2 to 10.0.0.50. What type of device should you select to connect the two groups of computers so that data communication can occur?
Router. You should select a router to connect the two groups. When computers are in different subnets, as these two groups are, you will require a device that can make decisions based on IP addresses. Routers operate at layer 3 of the Open Systems Interconnect (OSI) model and make data-forwarding decisions based on layer 3 networking information, which are IP addresses. They create routing tables that guide them in forwarding traffic out of the proper interface to the proper subnet.
The most effective way to mitigate congestion on a LAN would be to ______________.
Replacing the hub with a switch would reduce collisions and retransmissions, which would have the most impact on reducing congestion.
In the following work area, draw a line from the OSI model layer to its PDU.
Answer
What is a function of the WLAN Controller?
To automatically handle the configuration of wireless access points. Wireless LAN Controllers are used to manage anywhere from a few access points to thousands. The WLAN controller automatically handles the configuration of wireless access-points.
You need to provide network connectivity to 150 client computers that will reside in the same subnetwork, and each client computer must be allocated dedicated bandwidth. Which device should you use to accomplish the task?
Switch. You should use a switch to accomplish the task in this scenario. A switch is used to provide dedicated bandwidth to each node by eliminating the possibility of collisions on the switch port where the node resides. Switches work at layer 2 in the Open Systems Interconnection (OSI) model and perform the function of separating collision domains.
In the following work area, draw a line from the OSI model layer definition on the left to its description on the right.
Answer
What is the function of a firewall?
To monitor and control the incoming and outgoing network traffic. Firewalls are used to connect our trusted internal network such as the DMZ, to the untrusted outside network—typically the internet.
Which layer in the OSI reference model is responsible for determining the availability of the receiving program and checking to see whether enough resources exist for that communication?
D. The Application layer is responsible for identifying and establishing the availability of the intended communication partner and determining whether sufficient resources for the intended communication exist.
What happens in the trasnport and network layer in the OSI data encapsulation process?
A, D. The Transport layer segments data into smaller pieces for transport. Each segment is assigned a sequence number so that the receiving device can reassemble the data on arrival. The Network layer (layer 3) has two key responsibilities. First, this layer controls the logical addressing of devices. Second, the Network layer determines the best path to a particular destination network and routes the data appropriately.
Which of the following layers of the OSI model was later subdivided into two layers? What are those two sublayers?
Data Link. The IEEE Ethernet Data Link layer has two sublayers, the Media Access Control (MAC) layer and the Logical Link Control (LLC) layer.
While LLC is responsible for handling multiple Layer3 protocols (multiplexing/de-multiplexing) and link services like reliability and flow control, the MAC is responsible for framing and media access control for broadcast media.
What is a function of an access point (AP)?
To allow wireless devices to connect to a wired network. Wireless AP’s are very popular today and will be going away about the same time that rock n’ roll does. The idea behind these devices (which are layer 2 bridge devices) is to connect wireless products to the wired Ethernet network. The wireless AP will create a single collision domain and is typically its own dedicated broadcast domain as well.
A _____________ is an example of a device that operates only at the physical layer.
Hub. Hubs operate on the Physical Layer as they have no intelligence and send all traffic in all directions.
Which of the following is not a benefit of using a reference model?
- It divides the network communication process into smaller and simpler components.
- It encourages industry standardization.
- It enforces consistency across vendors.
- It allows various types of network hardware and software to communicate.
C. 3rd. While it is true that the OSI model’s primary purpose is to allow different vendors’ networks to interoperate, there is no requirement that vendors follow the model.
How many collision domains are present in the following diagram?
- The all-hub network at the bottom is one collision domain; the bridge network on top equals three collision domains. Add in the switch network of five collision domains—one for each switch port—and you get a total of nine.
