Review Questions
Use the questions in this section as a review of what you have learned in this chapter. The correct answers are found in Appendix A, “Answers to Chapter Review Questions.”
Which of the following statements is true about campus networks?
- The campus network describes the interconnections of servers in a data center.
- The campus network describes the WAN interconnectivity between two remote sites and head office.
- The campus network describes the network devices that interconnect end users to applications such as e-mail, the intranet, or the Internet over wire or wireless connections.
Which of the following is a disadvantage to using flat Layer 2 networks?
- Broadcast packets are flooded to every device in the network.
- No IP boundary to administer IP-based access control.
- A host flooding traffic onto the network effects every device.
- Scalability is limited.
- All the above
Why are networks designed with layers?
- Allows focus within specific layers due to grouping, segmentation, and compartmentalization
- Simplification of network design
- Optimizes use of physical interconnects (links)
- Optimizes application of policies and access control
- Eases network management
- All of the above
Identify the three layers of the hierarchical model for designing networks.
- Core
- Access
- Distribution
- Enterprise edge
- WAN
- Wireless
What is another common name for the core layer?
- Backbone
- Campus
- Data center
- Routing layer
In newer terminology, what layers are referred to as the spine layer and the leaf layer?
- The spine layer is the equivalent to the core layer, and the leaf layer is equivalent to the distribution layer.
- The spine layer is equivalent to the access layer, and the leaf layer is equivalent to the distribution layer.
- The spine layer is equivalent to the distribution layer, and the leaf layer is equivalent to the access layer.
- The spine layer is equivalent to the core layer, and the leaf layer is equivalent to the access layer.
Match each layer to its definition.
- Core
- Distribution
Access
- Connects PCs, wireless access points, and IP phones
- High-speed interconnectivity layer that generally supports routing capability
- Aggregates access layer switches and provides for policy control
Which of the following are generally true about recommended core layer designs?
- Requires high-availability and resiliency
- Connects critical application servers directly for optimal latency and bandwidth
- Leverages fixed form factor switches in large enterprises
In which layer are you most likely to find fixed Catalyst switches?
- Access layer
- Core layer
- Distribution layer
In which layer are you most likely to find modular Catalyst switches?
- Access layer
- Backbone layer
- Core layer
Which of the following are benefits to using Layer 3 in the access layer? (Choose two.)
- Reduced cost
- Reduced Layer 2 domain
- Reduced spanning-tree domain
- Mobility
Which of the following is the biggest disadvantage with using Layer 3 in the access layer using current technologies?
- More difficult troubleshooting
- Lack of broadcast forwarding
- Native mobility without additional features
- Lack of high availability
A Layer 2-only switch makes forwarding decisions based on what?
- Source MAC address
- Destination MAC address
- Source IP address
- Destination IP address
What does a switch do when it does not know how to forward a frame?
- Drops the frame
- Floods the frames on all ports in the same Layer 2 domain except the source port
- Stores the frame for later transmission
- Resends the frame out the port where it was received
The Layer 2 forwarding table of Cisco switches is also referred to as which of the following?
- CAM table
- Routing table
- MAC address table
- FIB table
Which of the following lookups does a Layer 2-only Cisco Catalyst switch perform on an ingress frame?
- Layer 2 forwarding for destination port
- ACL for access control
- NetFlow for statistics monitoring
- QoS for classification, marking, or policing
Which of the following are true about CAM and/or TCAM? (Choose three.)
- TCAM stands for ternary content-addressable memory.
- CAM provides three results: 0, 1, and don’t care.
- Leveraging CAM and TCAM ensures line-rate performance of the switch.
- CAM and TCAM are software-based tables.
- TCAM is leveraged by QoS and ACL tables.
Why is TCAM necessary for IP routing tables over CAM?
- TCAM supports longest matching instead of match or not match.
- TCAM is faster than CAM.
- TCAM memory is cheaper than CAM.
Cisco Catalyst switches leverage which of the following technologies for Layer 3 forwarding?
- Route caching
- Processor/CPU switching
- NetFlow
- CEF
Cisco Catalyst switches relay routing information to hardware components for additional performance and scalability (line-rate forwarding). What are the two common hardware types that receive relayed routing information?
- Centralized
- Distributed
- Aggregated
- Core-based
With regard to load balancing, what term describes the situation where less than optimal use of all links occurs?
- Reverse path forwarding (RPF)
- Polarization
- Inverse routing
- Unicast flooding
What is the default load-balancing mechanism found on Cisco Catalyst switches?
- Per-flow
- Per-destination IP address
- Per-packet
- Per-destination MAC address