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

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

CIT 470: Advanced Network and System Administration Network Topology Arrangement of network elements, showing physical or logical interconnections between nodes. Does not include info about: Distance Transmission rates Protocols Cabling types Image from http://en.wikipedia.org/wiki/Network_topology CIT 470: Advanced Network and System Administration

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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 http://en.wikipedia.org/wiki/Image:Ethernet_12U_box.jpg CIT 470: Advanced Network and System Administration

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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. Image from Ethernet: The Definitive Guide CIT 470: Advanced Network and System Administration

CIT 470: Advanced Network and System Administration Patch Panel Images from http://wwwx.cs.unc.edu/help/network/1998/cable_management.html and http://www.electralink.com/content/includes/gallery/PatchPanel-Terminations_Anadarko_BIG.jpg CIT 470: Advanced Network and System Administration

CIT 470: Advanced Network and System Administration Star Topology Cabling Image from Ethernet: The Definitive Guide CIT 470: Advanced Network and System Administration

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

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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

CIT 470: Advanced Network and System Administration 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