Designing and Supporting Computer Networks – Chapter 1
Explain How a Hierarchical Network Design Creates a Stable, Reliable, Scalable Network
Network requirements
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Ease of management
Fast recovery
Application response time
Fast troubleshooting
Four fundamental network design goals
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Scalability
Availability
Security
Manageability
Core Layer:
connects Distribution Layer devices
Distribution Layer
interconnects smaller LANs
Access Layer
provides connections for hosts and end devices
Subdividing the three-layer model into modular areas
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Enterprise campus
Server farm
Enterprise edge
Advantages of Modular Framework
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It creates a deterministic network with clearly defined boundaries between modules.
It eases the design task by making each module independent.
It provides scalability by allowing enterprises to add modules easily.
It enables the designer to add services and solution without changing the underlying network design
Steps in network design projects
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Identify the network requirements
Characterize the existing network
Design the network topology and solutions
Explain what Factors Need to be Considered when Designing the Network Core Layer
Network backbone
Goals of the Core Layer
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Provide 100% uptime
Maximize throughput
Facilitate network growth
-Combining routing and switching in the same device
-Redundancy and load balancing
-High-speed and aggregate links
-Quick convergence
- Full mesh topology
- Partial mesh topology
- Failure prevention
- Reducing human error
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Explain which Factors Need to be Considered when Designing the Distribution Layer of a Network
Filtering and managing traffic flow
Access control policies
Route summarization
Isolating Core Layer from Access Layer failures
Routing between VLANs
Explain how redundant links improve network reliability and stability
Explain how ACLs filter traffic for security and traffic management
Explain the concept of route summarization and describe how it is implemented at the Distribution Layer of the network
Explain which Factors Need to be Considered when Designing the Access Layer of a Network
- Physical location of equipment
- Wiring closets
- Converged networking
- Availability
-Naming structures
-VLAN architecture
-Traffic patterns
-Prioritization strategies
Functions of VLANs:
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Separate and classify traffic
Control broadcasts
Contain VLANs within a single wiring closet
QoS at the network edge:
- Classification
- Assigned priority
Security risks at the network edge:
- Authentication
- Wireless security
Security measures at the Access Layer
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Physical security
Strong passwords
SSH
Disabling unused ports
Security policy
Describe the Benefits and Security Implications of Creating Server Farms
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Defined entry and exit points for network traffic
Redundant, high-capacity links
Load balancing and failover
Lower cost of providing services
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Firewalls
LAN switch security features
Intrusion and prevention systems
Load balancers
Network analysis and management devices
DMZs
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Describe the Considerations of an Implementation of a Wireless Network Design
Customer requirements:
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Roaming
Authentication
Services and applications
Encryption
Coverage and number of users
Describe the Factors that Affect the Implementation of VPNs
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Cost of bandwidth
QoS
Security
Remote access