Term
| What are the three layers of the hierarchical network design model? |
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Definition
-Access Layer
-Distribution Layer
-Core Layer |
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Term
| What are the advantages of designing LANs using the hierarchical model? |
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Definition
-Easier to manage and expand
-Problems are solved more quickly
-Scalability
-Performance |
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Term
| What is the purpose of the access layer? |
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Definition
| It is to provide a means of connecting devices to the network and controlling which devices are allowed to communicate on the network. |
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Term
| What sort of devices are found at the access layer? |
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Definition
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Term
| What is the purpose of the distribution layer? |
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Definition
| Controls the flow of network traffic using policies and delineates broadcast domains by performing routing functions between virtual LANs defined at the access layer. |
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Term
| What sort of devices are found at the distribution layer? |
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Definition
-High performance switches
-Routers |
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Term
| What is the purpose of the core layer? |
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Definition
| The core layer is critical for inter connectivity between distribution layer devices, it is highly important for the core to be highly available and redundant. |
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Term
| What is a collapsed core model and where might it be used? |
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Definition
-Small networks
-Where the distribution layer and core layer are combined into one layer. |
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Term
| Why is redundancy important in a network? |
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Definition
| Redundancy provides and ensures path availability. |
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Term
| Which layers normally have redundancy built in? |
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Definition
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Term
| How can the hierarchical design help to give high performance? |
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Definition
| Properly designed hierarchical networks can achieve near wire speed between all devices. |
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Term
| How can switches at the different layers contribute to network security? |
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Definition
Access Layer - Port security options
Distribution Layer - ACLs |
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Term
| How does a hierarchical design help to make a network manageable? |
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Definition
| Each layer of the hierarchical design performs specific functions that are consistent throughout that layer. the network to scale without becoming overly complicated. |
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Term
| Should the same type of switch be used at each layer of the hierarchical design? |
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Definition
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Term
| What is "network diameter" in hierarchical network design? |
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Definition
| The number of devices that a packet has to cross before it reaches its destination. |
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Term
| What is network device latency? |
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Definition
1.)Delay between the time a device requests access to a network and the time it is granted permission to transmit.
2.)Delay between the time when a device receives a frame and the time that the frame is frowarded out of the destination port. |
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Term
| What sort of processing does a switch have to do on each packet? |
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Definition
| Each switch has to determine the destination MAC address of the frame, check its MAC address table and forward the frame out the appropiate port. |
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Term
| How can bandwidth aggregation be implemented? |
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Definition
| After bandwidth requirements of the network are known, links between specific switches can be aggregated, which is called link aggregation. |
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Term
| Why is redundancy not normally provided at the access layer? |
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Definition
-Cost
-Limited features in the end devices |
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Term
| When designing a new network at which layer would you start? |
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Definition
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Term
| What is a converged network? |
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Definition
| The process of combining voice and video communications on a data network. |
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Term
| What factors have slowed the move towards converged networks? |
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Definition
-Network infrastructure requirements
-Complex Management
-Network costs |
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Term
| What are the benefits of a converged network? |
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Definition
-One network to manage
-Manage one wired infrastructure
-Lower implementation and management costs |
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Term
| What is traffic flow analysis, and why might you want to do it? |
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Definition
| It is the process of measuring the bandwidth usage on a network and analyzing the data for the purpose of performance tuning, capacity planning, and making hardware improvement decisions. |
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Term
| How can measurements be made in order to carry out a traffic flow analysis? |
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Definition
-Manually monitor individual switch ports
-Traffic flow analysis tools(Automated Software) |
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Term
| How might you deal with a bottleneck where there is insufficient bandwidth? |
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Definition
-Aggregate links to accommodate bandwidth
-Replace slower switches with faster switches |
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Term
| Why is it important to produce a topology diagram as part of the network design process? |
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Definition
| It graphically displays any redundant paths or aggregated ports between switches that provide for resiliency and performance. It shows where and how many switches are in use on the network. |
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Term
| What are stackable switches? |
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Definition
| Connected by a special cable, effectively operate as one large switch. |
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Term
| What is port density of a switch? |
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Definition
| It is the number of ports available on a single switch. |
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Term
| If 80 outlets need to be connected to a switch, why is a single larger modular switch likely to be a better choice than four fixed configuration switches with 24 ports each? |
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Definition
| Modular switches can support very high port densities through the addition of multiple switch port line cards. |
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Term
| What is wire speed, and what is forwarding rate? |
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Definition
Wire Speed - is the data rate that each port on the switch is capable of obtaining.
Forwarding Rate - Defines the processing capabilities of a switch by rating how much data the switch can process per second. |
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Term
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Definition
| Allows a group of physical Ethernet links to create one logical Ethernet link for the purpose of providing fault tolerance and high - speed links between switches, routers, and servers. |
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Term
| What is PoE and what are its advantage and disadvantage? |
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Definition
-Power over Ethernet
-More flexibility
-IP Phones Power through Ethernet
-Costs |
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Term
| At which OSI layer do typical traditional switches operate? |
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Definition
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Term
| What is a multilayer switch? |
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Definition
| Switches that filters and forwards packets based on a MAC addresses and network addresses. |
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Term
| What features are required for access layer switches? |
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Definition
-Port security
-VLANs
-Fast Ethernet/Gigabit
-PoE
-Link aggregation
-QoS |
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Term
| What features are required for distribution layer switches? |
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Definition
-Layer 3 support
-Higher forwarding rate
-Gigabit Ethernet
-Redundant components
-ACLs
-link aggregation
-QoS |
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Term
| What features are required for core layer switches? |
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Definition
-Layer 3 support
-Very high forwarding rate
-Gigabit/10 Gigabit
-Redundant Components
-Link aggregation
-QoS |
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