INTERNETWORKING III
CHAPTER 4 STUDY GUIDE
1. The first step in designing a LAN is to establish and document the goals of the design. The following requirements tend to show up in most network designs:
· Functionality -The network must work. That is, it must allow users to meet their job requirements. The network must provide user-to-user and user-to-application connectivity with reasonable speed and reliability.
· Scalability -The network must be able to grow. That is, the initial design should grow without any major changes to the overall design.
· Adapatability -The network must be designed with an eye toward future technologies, and it should include no element that would limit implementation of new technologies as they become available.
· Manageability -The network should be designed to facilitate network monitoring and management to ensure ongoing stability of operation.
2. To design LANs for high-speed technologies and multimedia-based applications, network designers should address the following critical components of the overall LAN design:
· The function and placement of servers
· Collision detection
· Segmentation
· Bandwidth versus broadcast domains
3. Servers can be categorized into two distinct classes: enterprise servers and workgroup servers.
4. Intranet Web systems, Domain Name System (DNS) and E-mail are services that everyone in an organization would need because it is a centralized function. These kinds of services belong on an enterprise server. These servers should be placed in the main distribution facility (MDF).
5. Workgroup servers should be placed in intermediate distribution facilities (IDF) closest to the users accessing the applications on these servers.
6. Within the MDF and IDFs, the Layer 2 LAN switches should have 100 Mbps or more allocated for these servers.
7. New desktops and servers should be outfitted with 10 / 100 Mbps Ethernet network interface cards (NICs) to provide the most configuration flexibility, thus enabling network administrators to dedicate bandwidth to individual end stations as needed.
8. You should decide carefully on the selection and placement of networking devices to be used in the LAN in order to decrease the collision detection and media contention on a network. This reduction in bandwidth can be remedied by segmenting the network by using bridges, switches, or routers.
9. Layer 2 (the data link layer) bridges or switches can be used to segment a logical bus topology and create separate collision domains, which results in more bandwidth being available to individual stations.
10. A bandwidth domain is everything associated with one port on a bridge or switch. In the case of an Ethernet switch, also known as a collision domain.
11. For a LAN to be effective and serve the needs of its users, it should be designed and implemented according to a planned series of systematic steps, which include the following:
· Gathering the users’ requirements and expectations
· Analyzing requirements
· Designing the Layer 1, 2, and 3 LAN structure (topology)
· Documenting the logical and physical network implementation
12. The first step in designing a network should be to gather data about the organizational structure.
¨ Corporate structure
¨ Business information flow
¨ Applications in use
¨ Current topology
¨ Performance characteristics of current network
You need to answer the following questions:
¨ Who are the people who will be using the network?
¨ What is their level of skill, and what are their attitudes toward computers and computer applications?
¨ Has some data been declared mission critical?
¨ Have some operations been declared mission critical?
¨ What protocols are allowed on the network? Are only certain desktop hosts supported?
¨ How are these resources currently linked and shared?
¨ What financial resources does the organization have available?
13. Availability measures the usefulness of the network. Many things affect availability, including the following:
· throughput
· response time
· access to resources
14. Another component of the analysis phase is assessing the user requirements. A LAN that is incapable of supplying prompt and accurate information to its users is of little use.
15. The major pieces of a LAN topology design can be broken into three unique categories of the OSI reference model:
· network layer (3)
· data link layer (2)
· physical layer (1)
16. The physical cabling is one of the most important components to consider when designing a network.
17. List the two most recommended types of cabling to use below.
· UTP
· fiber
18. The overall structure of the Layer 1 cabling media follows the TIA/EIA-586-A standard for layout and connection of wiring schemes.
19. Most network problems are caused by Layer 1 issues.
20. Whether you are designing a new network or recabling an existing one, fiber optic cable should be used in the backbone and risers, with Category 5 UTP cable in the horizontal runs. The cable upgrade should take priority over any other needed changes.
21. The logical diagram is the network topology model without all the detail of the exact installation path of the cabling. It is the basic road map of the LAN. Elements include:
· The exact locations of the MDF and IDF wiring closets.
· The type and quantity of cabling used to interconnect the IDFs with the MDF, along with how many spare cables are available for increasing the bandwidth between the wiring closets.
· Detailed documentation of all cable runs includes the identification numbers, and which port on the HCC or VCC the run is terminated on.
22. The MDF is the central point in the LAN for traffic destination.
23. After you have developed the IP addressing scheme for the customer, you should document it by site and by network within the site. A standard convention should be set for addressing important hosts on the network. This addressing scheme should be kept consistent throughout the entire network. By creating addressing maps, you can get a snapshot of the network. Creating physical maps of the network helps you troubleshoot the network.
24. Which device is one of the most common layer two devices?
Active
Hub
LAN switch
Passive
Hub
Router
25. A broadcast domain is everything associated with one port on what device?
Active
hub
Bridge
Router
Switch
26. A bandwidth domain or collision domain is everything associated with a port on what device?
Active
hub
Bridge
Repeater
Switch
27. Network traffic problems can be generated by ___________.
Client/server
applications
Host/terminal
applications
Routing
protocols
All of the above
28. The use of bridges and switches for segmentation results in _______________.
A
larger overall network
Multiple
broadcast domains
Multiple collision
domains
Single
collision domains
29. In a star topology using CAT 5 cable, what is the catchment area?
100ft
100m
200ft
200m
30. By creating multiple wiring closets, what else is being created?
Multiple
broadcast domains
Multiple catchment areas
Multiple
collision domains
Multiple
LANs
31. In a pure LAN switch environment what is the size of the collision domain?
All
hosts
Four
hosts
The
number of hosts in the broadcast domain
Two hosts
32. Routers provide ____________ between VLANs.
Communication
Frame
tagging
No
services
None
of the above
33. How do Routers allow for segmentation of the network?
Collision
domains
Logical
segments only
Physical and logical
segments
Physical
segments only
34. The MDF to IDF cabling should be _________________.
10Base2
10BaseT
Ethernet
Fast Ethernet
35. VLANs provide ________________ and security.
Broadcast containment
Decreased
security
Larger
broadcast domains
Physical networks
