CIT 470: Advanced Network and System Administration

1. CIT 470: Advanced Network and System Administration Networks CIT 470: Advanced Network and System Administration

2. Topics • Network Topology • Structured Cabling • Simple Host Routing • Overlay Networks • Monitoring CIT 470: Advanced Network and System Administration

3. Network Topology Arrangement of network elements, showing physical or logical interconnections between nodes. Does not include info about: • Distance • Transmission rates • Protocols • Cabling types CIT 470: Advanced Network and System Administration

4. Star Topology • Network connected to a central node using a single link. • All data transmitted between nodes goes through central node. • Easy to understand, simple, affordable. • Single point of failure. CIT 470: Advanced Network and System Administration

5. Ring Topology • Each node is connected to two other nodes, with first and last node connected to each other. • All devices have two connections to network, so any link can fail w/o causing a problem. • Dual ring has two connections to each node. CIT 470: Advanced Network and System Administration

6. Structured Cabling Telecom cabling infrastructure consisting of • Entrance facilities: where building interfaces to ouside world. • Equipment room: more complex equipment (routers, major cable terminations.) • Building backbone: star topology providing access to all wiring closets, equipment rooms, and entrance facilities. • Telecom closet: wiring closet where horizontal cable for floor is terminated. • Horizontal cabling: extends from telecom closet to end user devices in the work area. • Work area: office space, labs, etc. where computers and other equipment are located. CIT 470: Advanced Network and System Administration

7. Wiring Closets • Small room where • cables are connected • from main network to • local devices, a/k/a • a distribution frame. • Needs: • Reliable power • A/C • Physical security CIT 470: Advanced Network and System Administration

8. IDFs and MDFs Intermediate Distribution Frame (IDF) • One per floor. • Connects end users to network. Main Distribution Frame (MDF) • Connects all the MDFs. • Often located in data center. CIT 470: Advanced Network and System Administration

9. Patch Panel A panel that houses cable connections. • Front: short patch cables. • Back: longer permanent cables. Allows you to change cable path w/o new cables. CIT 470: Advanced Network and System Administration

10. Patch Panel CIT 470: Advanced Network and System Administration

11. Star Topology Cabling CIT 470: Advanced Network and System Administration

12. Star Topology Wiring Advantages • Central wiring hubs make it easier to move, add, or change cabling. • Central cabling points allow faster troubleshooting. • Independent point to point links prevent cable problems from affecting other links. • Central wiring hubs can allow easier upgrades to new technologies. CIT 470: Advanced Network and System Administration

13. Cabling Contractors • Cabling an entire building is a major project. • Cable contractors know how • Plan cabling for an entire building • Estimate cabling and install hosts • Structured cable standards • Electrical safety standards • Fire safety standards CIT 470: Advanced Network and System Administration

14. Documentation • Logical map • Logical network topology • Network numbers, names, speeds • Labeling • Label both ends of each cable. • Cables can be difficult to label, but manufacturers will print serial numbers. • Include text comment on each interface in router/switch software. CIT 470: Advanced Network and System Administration

15. Simple Host Routing Machines with one NIC only need two routes: • Local subnet: direct connection. • Everything else goes to local gateway router. Don’t enable routing protocols on PCs. • Makes networking more complex. • Decreases network performance w/ broadcasts. • Badly configured PC can send bad routes to other PCs and routers, breaking network. CIT 470: Advanced Network and System Administration

16. Overlay Networks A logical topology on top of physical topology. • VPN: connect remote users/sites to main site as if a single secure WAN existed over Internet. • VLAN: treat any connection as belonging to any subnet, no matter what the physical cabling is like. Eliminates need to recable to move machines to different subnets. CIT 470: Advanced Network and System Administration

17. Monitoring Need two types of monitoring • Real-time alerts: alert when network interface goes up or down, heavy load, security, etc. • Historical trends: record overall network usage in order to plan for future capacity and detect behavorial abnormalities before they become problems. CIT 470: Advanced Network and System Administration

18. References • Thomas A. Limoncelli, The Practice of System and Network Administration, 2nd ed, Addison-Wesley, 2007. • Kennedy Clark and Kevin Hamilton, Cisco LAN Switching, Cisco Press, 1999. • Charles E. Spurgeon, Ethernet: The Definitive Guide, O’Reilly, 2000. • John Vacca, The Cabling Handbook, 2nd ed, Pearson PTR, 2000. CIT 470: Advanced Network and System Administration