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

2. 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

3. 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
CIT 470: Advanced Network and System Administration

4. 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

5. 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

6. 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

7. 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
CIT 470: Advanced Network and System Administration

8. 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

9. 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

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

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

14. 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

15. 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

16. 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

17. 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

18. 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