CCNA 2 v6.0 (Routing & Switching Essentials v6) Chapter 4: Switched Networks: Check Your Understanding Questions Answers
1. What is a basic function of the Cisco Borderless Architecture distribution layer?
- Acting as a backbone
- Aggregating all the campus blocks
- Aggregating Layer 2 and Layer 3 routing boundaries
- Providing access to end-user devices
Explanation: One of the basic functions of the distribution layer of the Cisco Borderless Architecture is to perform routing between different VLANs. Acting as a backbone and aggregating campus blocks are functions of the core layer. Providing access to end user devices is a function of the access layer.
2. A network designer must provide a rationale to a customer for a design that will move an enterprise from a flat network topology to a hierarchical network topology. Which two features of the hierarchical design make it the better choice? (Choose two.)
- Easier to provide redundant links to ensure higher availability
- Less required equipment to provide the same performance levels
- Lower bandwidth requirements
- Reduced cost for equipment and user training
- Simpler deployment for additional switch equipment
Explanation: A hierarchical design for switches helps network administrators when planning and deploying a network expansion, performing fault isolation when a problem occurs, and providing resiliency when traffic levels are high. A good hierarchical design has redundancy when it can be afforded so that one switch does not cause all networks to be down.
3. What is a collapsed core in a network design?
- A combination of the functionality of the access and core layers
- A combination of the functionality of the access and distribution layers
- A combination of the functionality of the access, distribution, and core layers
- A combination of the functionality of the distribution and core layers
Explanation: A collapsed core design is appropriate for a small, single-building business. This type of design uses two layers (the collapsed core and distribution layers consolidated into one layer and the access layer). Larger businesses use the traditional three-tier switch design model.
4. Which two previously independent technologies should a network administrator attempt to combine after choosing to upgrade to a converged network infrastructure? (Choose two.)
- User data traffic
- VoIP phone traffic
- Scanners and printers
- Mobile cell phone traffic
- Electrical system
Explanation: A converged network provides a single infrastructure that combines voice, video, and data. Analog phones, user data, and point-to-point video traffic are contained within the single network infrastructure of a converged network.
5. What is a definition of a two-tier LAN network design?
- Access, distribution, and core layers collapsed into one tier, with a separate backbone layer
- Access and core layers collapsed into one tier, and the distribution layer on a separate tier
- Access and distribution layers collapsed into one tier, and the core layer on a separate tier
- Distribution and core layers collapsed into one tier, and the access layer on a separate tier
Explanation: Maintaining three separate network tiers is not always required or cost-efficient. All network designs require an access layer, but a two-tier design can collapse the distribution and core layers into one layer to serve the needs of a small location with few users.
6. A local law firm is redesigning the company network so that all 20 employees can be connected to a LAN and to the Internet. The law firm would prefer a low-cost and easy solution for the project. What type of switch should be selected?
- Fixed configuration
- Modular configuration
- Stackable configuration
- StackPower
- StackWise
Explanation: A fixed-configuration switch would meet all of the requirements of the law firm.
7. What are two advantages of modular switches over fixed-configuration switches? (Choose two.)
- Increased scalability
- Lower cost per switch
- Lower forwarding rates
- Need for fewer power outlets
Explanation: Fixed-configuration switches, although lower in price, have a designated number of ports and no ability to add ports. They also typically provide fewer high-speed ports. To scale switching on a network that consists of fixed-configuration switches, more switches need to be purchased. This increases the number of power outlets that need to be used. Modular switches can be scaled simply by purchasing additional line cards.
8. What is one function of a Layer 2 switch?
- Determines which interface is used to forward a frame based on the destination MAC address
- Duplicates the electrical signal of each frame to every port
- Forwards data based on logical addressing
- Learns the port assigned to a host by examining the destination MAC address
Explanation: A switch builds a MAC address table of MAC addresses and associated port numbers by examining the source MAC address found in inbound frames. To forward a frame onward, the switch examines the destination MAC address, looks in the MAC address for a port number associated with that destination MAC address, and sends it to the specific port. If the destination MAC address is not in the table, the switch forwards the frame out all ports except the inbound port that originated the frame.
9. What criteria are used by a Cisco LAN switch to decide how to forward Ethernet frames?
- Destination IP address
- Destination MAC address
- Egress port
- Path cost
Explanation: Cisco LAN switches use the MAC address table to make decisions of traffic forwarding. The decisions are based on the ingress port and the destination MAC address of the frame. The ingress port information is important because it carries the VLAN to which the port belongs.
10. Which network device can be used to eliminate collisions on an Ethernet network?
- Firewall
- Hub
- Router
- Switch
Explanation: A switch provides microsegmentation so that no other device competes for the same Ethernet network bandwidth.
11. Which type of address does a switch use to build the MAC address table?
- Destination IP address
- Destination MAC address
- Source IP address
- Source MAC address
Explanation: When a switch receives a frame with a source MAC address that is not in the MAC address table, the switch adds that MAC address to the table and maps that address to a specific port. Switches do not use IP addressing in the MAC address table.
12. What are two reasons a network administrator would segment a network with a Layer 2 switch? (Choose two.)
- To create fewer collision domains
- To create more broadcast domains
- To eliminate virtual circuits
- To enhance user bandwidth
- To isolate ARP request messages from the rest of the network
- To isolate traffic between segments
Explanation: A switch can create temporary point-to-point connections between the directly attached transmitting and receiving network devices. The two devices have full-bandwidth full duplex connectivity during the transmission. Segmenting adds collision domains to reduce collisions.
13. Which statement describes the microsegmentation feature of a LAN switch?
- All ports inside the switch form one collision domain.
- Each port forms a collision domain.
- Frame collisions are forwarded.
- The switch will not forward broadcast frames.
Explanation: When a LAN switch with the microsegmentation feature is used, each port represents a segment that in turns forms a collision domain. If each port is connected with an end user device, there will be no collisions. However, if multiple end devices are connected to a hub and the hub is connected to a port on the switch, some collisions will occur in that particular segment, but not beyond it.
14. A __________________ network is one that uses the same infrastructure to carry voice, data, and video signals.
converged