1. Copyright 2002 Year 2 - Chapter 4/Cisco 3 - Module 4 LAN Design By Carl Marandola

2. Copyright 2002 Objectives Explain LAN design goals Identify LAN design issues Explain network design methodology Describe how to gather and analyze network equipment Identify Layer 1 (media and topology) design issues Identify Layer 2 (LAN switching) design issues Identify Layer 3 (routing) design issues Describe the physical and logical network implementation documentation

3. Copyright 2002 LAN Design Goals Functionality –The network must work. Scalability –The network must be able to grow and contract to meet the needs of the organization. Adaptability –The network must adapt to new technologies. Manageability –The network must support network monitoring and management.

4. Copyright 2002 Critical Components of LAN Design Function and Placement of Servers Intranets Collision Detection (Ethernet) Segmentation Bandwidth Versus Broadcast Domains

5. Copyright 2002 Server Placement Servers can be categorized into two distinct classes: –Enterprise servers –Workgroup (departmental) servers

6. Copyright 2002 Intranets Centralized Web Servers (Comparable to Enterprise Servers) Limited to Internal Users –Those that have logged in to corporate network Accessed by Web Browser Many Day-to-Day Job Functions on the Web

7. Copyright 2002 Collision Detection (Ethernet) Legacy Ethernet –Contention refers to excessive collisions caused by too many devices vying for services. –Broadcasts becomes excessive when: Too many client packets looking for services Too many server packets announcing services Too many routing table updates Too many broadcast-dependent protocols, such as ARP, DHCP, and so forth

8. Copyright 2002 Broadcast and Collision Domains

9. Copyright 2002 Network Design Methodology Gathering Requirements Analyzing Requirements Designing the Network Topology –Designing the Layer 1, 2, and 3 LAN structure –Documenting the logical and physical network

10. Copyright 2002 Gathering Requirements Who will be using the network? –What resources do they need to access? –What is their level of skill? –What are their attitudes toward computers and applications? What data and processes are mission-critical? What protocols are allowed on the network? What desktop hosts (OSs) are supported? Who has authority over addressing, naming, topology design, and configuration? What about the existing computer hardware and software? –How are these resources currently linked and shared? What financial resources are available? –Who controls these resources?

11. Copyright 2002 Analyzing Requirements

12. Copyright 2002 Develop a Physical Topology

13. Copyright 2002 OSI Layer 1, 2, and 3 Issues

14. Copyright 2002 Layer 1 Topology: Signaling Method, Medium Type, and Maximum Length

15. Copyright 2002 MDF in a Star Topology

16. Copyright 2002 MDFs and IDFs

17. Copyright 2002 Extended Star

18. Copyright 2002 10BaseT, 100BaseTX, and 1000BaseX Ethernet 10 Mbps (and 100 Mbps) to desktops Vertical cabling 100 Mbps (or Gigabit) between MDFs and IDFs 100 Mbps (or Gigabit) server to network Often multiple links combined into channels to provide increased bandwidth in vertical runs and server connections Fast Ethernet or Gigabit Ethernet

19. Copyright 2002 Elements of a Logical Topology Diagram

20. Copyright 2002 Cut Sheet

21. Copyright 2002 Select Layer 2 Devices

22. Copyright 2002 Asymmetric Switching

23. Copyright 2002 Switches to Reduce Congestion

24. Copyright 2002 Determining the Number of Cable Runs and Drops

25. Copyright 2002 Hubs Share (Split) Bandwidth

26. Copyright 2002 Switches, Hubs, and Collision Domains Switches combined with full-duplex create collision-free domains.

27. Copyright 2002 Layer 3 Design

28. Copyright 2002 VLANs in the Design

29. Copyright 2002 Routers Provides Logical Structure to a Network

30. Copyright 2002 Diagramming a Standards- Based LAN with Routers

31. Copyright 2002 Logical Maps

32. Copyright 2002 Addressing Maps

33. Copyright 2002 Physical Maps