Copyright 2002Cisco Press: CCNA Instructor’s Manual Year 2 - Chapter 4/Cisco 3 - Module 4 LAN Design
Copyright 2002Cisco Press: CCNA Instructor’s Manual 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.
Copyright 2002Cisco Press: CCNA Instructor’s Manual Critical Components of LAN Design Function and Placement of Servers Intranets Collision Detection (Ethernet) Segmentation Bandwidth Versus Broadcast Domains
Copyright 2002Cisco Press: CCNA Instructor’s Manual Server Placement Servers can be categorized into two distinct classes: –Enterprise servers –Workgroup (departmental) servers
Copyright 2002Cisco Press: CCNA Instructor’s Manual 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
Copyright 2002Cisco Press: CCNA Instructor’s Manual 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
Copyright 2002Cisco Press: CCNA Instructor’s Manual Broadcast and Collision Domains
Copyright 2002Cisco Press: CCNA Instructor’s Manual 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
Copyright 2002Cisco Press: CCNA Instructor’s Manual 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?
Copyright 2002Cisco Press: CCNA Instructor’s Manual Develop a Physical Topology
Copyright 2002Cisco Press: CCNA Instructor’s Manual OSI Layer 1, 2, and 3 Issues
Copyright 2002Cisco Press: CCNA Instructor’s Manual Layer 1 Topology: Signaling Method, Medium Type, and Maximum Length
Copyright 2002Cisco Press: CCNA Instructor’s Manual MDF in a Star Topology
Copyright 2002Cisco Press: CCNA Instructor’s Manual MDFs and IDFs
Copyright 2002Cisco Press: CCNA Instructor’s Manual Extended Star
Copyright 2002Cisco Press: CCNA Instructor’s Manual 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
Copyright 2002Cisco Press: CCNA Instructor’s Manual Elements of a Logical Topology Diagram
Copyright 2002Cisco Press: CCNA Instructor’s Manual Cut Sheet
Copyright 2002Cisco Press: CCNA Instructor’s Manual Select Layer 2 Devices
Copyright 2002Cisco Press: CCNA Instructor’s Manual Asymmetric Switching
Copyright 2002Cisco Press: CCNA Instructor’s Manual Switches to Reduce Congestion
Copyright 2002Cisco Press: CCNA Instructor’s Manual Determining the Number of Cable Runs and Drops
Copyright 2002Cisco Press: CCNA Instructor’s Manual Hubs Share (Split) Bandwidth
Copyright 2002Cisco Press: CCNA Instructor’s Manual Switches, Hubs, and Collision Domains Switches combined with full-duplex create collision-free domains.
Copyright 2002Cisco Press: CCNA Instructor’s Manual Layer 3 Design
Copyright 2002Cisco Press: CCNA Instructor’s Manual VLANs in the Design
Copyright 2002Cisco Press: CCNA Instructor’s Manual Routers Provides Logical Structure to a Network
Copyright 2002Cisco Press: CCNA Instructor’s Manual Diagramming a Standards- Based LAN with Routers
Copyright 2002Cisco Press: CCNA Instructor’s Manual Logical Maps
Copyright 2002Cisco Press: CCNA Instructor’s Manual Addressing Maps
Copyright 2002Cisco Press: CCNA Instructor’s Manual Physical Maps