1. 1 13-Jun-15 S Ward Abingdon and Witney College LAN design CCNA Exploration Semester 3 Chapter 1

2. 2 13-Jun-15 S Ward Abingdon and Witney College Topics Networks and business needs The 3-level hierarchical network design model Including voice and video over IP in the design Devices at each layer of the hierarchy Cisco switches for each layer

3. 3 13-Jun-15 S Ward Abingdon and Witney College Semester 3 LAN DesignBasic Switch Concepts VLANs VTP STP Inter-VLAN routing Wireless

4. 4 13-Jun-15 S Ward Abingdon and Witney College Hierarchical design model

5. 5 13-Jun-15 S Ward Abingdon and Witney College Hierarchical design model High speed backbone.

6. 6 13-Jun-15 S Ward Abingdon and Witney College Hierarchical design model Subnets, VLANs, routing, flow control, security.

7. 7 13-Jun-15 S Ward Abingdon and Witney College Hierarchical design model Connects end devices. Controls which devices connect.

8. 8 13-Jun-15 S Ward Abingdon and Witney College Collapsed core Small network: merged core and distribution

9. 9 13-Jun-15 S Ward Abingdon and Witney College Logical and physical layout Logical – how they connect. Physical – where they are. Logical connections not obvious from looking.

10. 10 13-Jun-15 S Ward Abingdon and Witney College Benefits of Hierarchical Network Scalability – easy to expand Redundancy – at core and distribution layers Performance – route packets through fast devices Security – at access and distribution layers Manageability – similar functions within layer Maintainability - modular

11. 11 13-Jun-15 S Ward Abingdon and Witney College Design principles Network diameter – how many devices must packet pass through? Keep it low. Bandwidth aggregation – combine ports where high bandwidth is needed. Redundant links/devices – in core and distribution layers. Too expensive for access. Start design at the access layer. How many devices, how much bandwidth needed?

12. 12 13-Jun-15 S Ward Abingdon and Witney College Converged network Combines data, voice, video. (Not converged as in “all routers have consistent information”. Same word used.) Needs quality of service (QoS) to give priority to voice and video. Was very expensive, needed expertise, needed to replace legacy equipment. Now more affordable.

13. 13 13-Jun-15 S Ward Abingdon and Witney College Advantages of converged network One network to manage/ keep up to date One set of cabling and networking devices One group of people to run it One service provider Can have voice and video on PC using headset, webcam and software – no separate equipment.

14. 14 13-Jun-15 S Ward Abingdon and Witney College Choosing switches Carry out Traffic Flow Analysis using software to monitor amount and source of traffic. Allow for growth. Carry out User Communities Analysis. Group by job function. How many ports? How much bandwidth? Allow for growth. Carry out Data Stores and Data Servers analysis. Traffic to, from, between.

15. 15 13-Jun-15 S Ward Abingdon and Witney College Topology Diagram Ports? Bandwidth? Bottlenecks? Layers? Routes? Redundancy?

16. 16 13-Jun-15 S Ward Abingdon and Witney College Topology Diagram Ports? Bandwidth? Bottlenecks? Layers? Routes? Redundancy? Document it now

17. 17 13-Jun-15 S Ward Abingdon and Witney College Choosing switches (cont d ) Form factor Fixed configuration – ports on chassis Modular – ports on cards Stackable – act as one switch, linked by special ports. 1 rack unit (1U)

18. 18 13-Jun-15 S Ward Abingdon and Witney College Choosing switches (cont d ) Port density – how many ports? (Allow for links between switches.) Forwarding rate – How many Gbps can it process? Can all ports work simultaneously at maximum speed? Link aggregation (EtherChannel) – up to 8 ports bound together, acting as one, with combined bandwidth – can it do this?

19. 19 13-Jun-15 S Ward Abingdon and Witney College Choosing switches (cont d ) Power over Ethernet (PoE) for IP phones, network access points. Do you need it? It adds to the cost. Multilayer switch needed? Typical switch works at Data Link layer (2), uses MAC addresses. Multilayer also works at Network layer (3), routes between subnets.

20. 20 13-Jun-15 S Ward Abingdon and Witney College Access Layer Switch Features Port security – choose which devices may connect. All Cisco switches support this. VLANs – connected devices on different subnets. Speed – Fast Ethernet (100Mbps) or Gigabit. Power over Ethernet (PoE) – expensive Link aggregation – for uplinks Quality of service (QoS) if needed

21. 21 13-Jun-15 S Ward Abingdon and Witney College Distribution Layer Switch Features Layer 3 support – route between VLANs High forwarding rate (processing) Port speed Gbps, 10Gbps ports Redundancy Security – Access control lists Link aggregation Quality of service Availability. Hot swappable power supply?

22. 22 13-Jun-15 S Ward Abingdon and Witney College Core Layer Switch Features Support for Network layer (3) - routing Very high forwarding rate Very high port speed (1Gbps, 10Gbps) Redundancy Link aggregation Quality of service Avoid security and other distractions here. Go for speed.

23. 23 13-Jun-15 S Ward Abingdon and Witney College Catalyst Switch product lines

24. 24 13-Jun-15 S Ward Abingdon and Witney College Catalyst Switch product lines Concentrate on general features

25. 25 13-Jun-15 S Ward Abingdon and Witney College The End