1. Chapter Six
Networking
Hardware

2. Objectives Identify functions of LAN connectivity hardware
Install and configure a network adapter (network interface card)
Identify problems associated with connectivity hardware

3. Objectives
Describe the factors involved in choosing a network adapter, hub, switch, or router
Describe the functions of repeaters, hubs, bridges, switches, and gateways
Describe the uses and types of routing protocols

4. Network Adapters Also called network interface cards (NICs)
Connectivity devices enabling a workstation, server, printer, or other node to receive and transmit data over the network media
In most modern network devices, network adapters contain the data transceiver

5. Types of Network Adapters
For a desktop or tower PC, network adapter is likely to be a type of expansion board
Expansion boards connect to the system board through expansion slots
The circuit used by the system board to transmit data to the computer’s components is the computer’s bus

6. Types of Network Adapters
PC bus types you may encounter:
Industry Standard Architecture (ISA)
MicroChannel Architecture (MCA)
Extended Industry Standard Architecture (EISA)
Peripheral Component Interconnect (PCI)
Figure 6-1: The four primary bus architectures

7. Types of Network Adapters
Figure 6-2: A system board with multiple bus types

8. Types of Network Adapters
PCMIA
Developed in early 1990s to provide standard interface for connecting any type of device to a portable computer
More commonly known as PC Cards
Figure 6-3: Typical PC Card network adapter

9. Types of Network Adapters
USB (universal serial bus) port
Standard external bus that can be used to connect multiple types of peripherals
Figure 6-4: A USB network adapter

10. Types of Network Adapters
Figure 6-5: A parallel port network adapter

11. Types of Network Adapters
Figure 6-6: Wireless network adapters

12. Types of Network Adapters
Figure 6-7: A variety of Ethernet network adapters

13. Types of Network Adapters
Figure 6-8: Token Ring network adapters

14. Types of Network Adapters
Figure 6-9: Ethernet network adapters for printers

15. Installing Network Adapters
To install modern network adapters, first install hardware, then install software shipped with NIC
In some cases you must perform a third step:
Configure the firmware
Electrically erasable programmable read-only memory (EEPROM)
Type of ROM found on a circuit board
Configuration information can be erased and rewritten through electrical pulses

16. Installing and Configuring Network Adapter Hardware
Figure 6-10: A properly inserted network adapter

17. Installing and Configuring Network Adapter Hardware
Figure 6-11: Installing a PC Card network adapter

18. Installing and Configuring Network Adapter Hardware
Jumper
Small, removable piece of plastic that contains a metal receptacle
Figure 6-12: A jumper and a row of pins indicating two different settings

19. Installing and Configuring Network Adapter Hardware
DIP switch
Small, plastic toggle switch that represents “on” or “off” status
Figure 6-13: DIP switches on a NIC

20. Installing and Configuring Network Adapter Software
Ensure that the correct device driver is installed for the network adapter and that it is configured properly
Device driver
Software that enables an attached device to communicate with computer’s operating system

21. Installing and Configuring Network Adapter Software
Figure 6-14: Windows 2000 Upgrade Device Driver Wizard

22. IRQ (Interrupt Request Line)
Message to the computer that instructs it to stop what it is doing and pay attention to something else
An interrupt is the wire on which a device issues voltage to signal this request
Each interrupt must have a unique IRQ number

23. IRQ (Interrupt Request Line)
Table 6-1: IRQ assignments

24. IRQ (Interrupt Request Line)
When two devices attempt to use the same IRQ, any of the following problems may occur:
Computer may lock up or “hang” either upon starting or when operating system is loading
Computer may run much slower than usual
Though computer’s network adapter may work properly, other devices may stop working
Video or sound card problems may occur
Computer may fail to connect to the network
Computer may experience intermittent data errors during transmission

25. IRQ (Interrupt Request Line)
Figure 6-15: Computer resource settings in Windows 2000

26. IRQ (Interrupt Request Line)
CMOS (complementary metal oxide semiconductor)
Firmware on a PC’s system board that enables you to change its devices’ configurations
Information saved in CMOS is used by the computer’s BIOS (basic input/output system)
BIOS is a simple set of instructions enabling a computer to initially recognize its hardware

27. Memory Range and Base I/O Port
Hexadecimal number indicating the area memory that the network adapter and CPU will use for exchanging, or buffering, the data
Base I/O port
Setting that specifies, in hexadecimal notation, which area of memory will act as a channel for moving data between the network adapter and CPU

28. Firmware Settings
Once you have adjusted the network adapter’s system resources, you may need to modify its transmission characteristics
These settings are held in the adapter’s firmware
Loopback plug
Plugs into port and crosses over the transmit line to the receive line so that the outgoing signal can be redirected back into the computer for testing

29. Choosing the Right Network Adapter
Table 6-2: Network adapter characteristics

30. Repeaters
Connectivity devices that regenerate and amplify an analog or digital signal
Figure 6-16: Repeaters

31. Hubs
Multiport repeater containing multiple ports to interconnect multiple devices
Figure 6-17: Detailed diagram of a hub

32. Hubs Elements shared by most hubs: Ports Uplink port
Port for management console
Backbone port
Link LED

33. Hubs Elements shared by most hubs (cont.):
Traffic (transmit or receive) LED
Collision LED (Ethernet hubs only)
Power supply
Ventilation fan

34. Figure 6-18: Hubs in a network design

35. Hubs Passive hubs Intelligent hubs Only repeats signal
Possesses processing capabilities

36. Standalone Hubs
Hubs that serve a group of computers that are isolated from the rest of the network
Best suited to small, independent departments, home offices, or test lab environments
Disadvantage to using a single hub for many connection ports is that it introduces a single point of failure on the network

37. Stackable Hubs
Physically designed to be linked with other hubs in a single telecommunications closet
Figure 6-21: Rack-mounted stackable hubs
Figure 6-20: Stackable hubs

38. Modular Hubs and Intelligent Hubs
Provide a number of interface options within one chassis
Intelligent hubs
Also called managed hubs
Network administrators can store the information generated by intelligent hubs in a MIB (management information base)

39. Installing a Hub
As with network adapters, the best way to ensure a hub is properly installed is to follow the manufacturer’s guidelines
Figure 6-22: Connecting a workstation to a hub

40. Choosing the Right Hub
Factors to consider when selecting the right hub for your network:
Performance
Cost
Size and growth
Security
Management benefits
Reliability

41. Bridges
Like a repeater, a bridge has a single input and single output port
Unlike a repeater, it can interpret the data it retransmits
Figure 6-23: A bridge

42. Figure 6-24: A bridge’s use of a filtering database
Collection of data created and used by a bridge that correlates the MAC addresses of connected workstations with their locations
Also known as a forwarding table
Figure 6-24: A bridge’s use of a filtering database

43. Bridges Spanning tree algorithm Transparent bridging
Routine that can detect circular traffic patterns and modify the way multiple bridges work together, in order to avoid such patterns
Transparent bridging
Method used on many Ethernet networks
Source-route bridging
Method used on most Token Ring networks
Translation bridging
Method that can use different logical topologies

44. Switches Subdivide a network into smaller logical pieces
Figure 6-25: Examples of LAN switches

45. Cut-Through Mode and Store and Forward Mode
Switching mode in which switch reads a frame’s header and decides where to forward the data before it receives the entire packet
Cut-through switches can detect runts, or packet fragments
Store and forward mode
Switching mode in which switch reads the entire data frame into its memory and checks it for accuracy before transmitting the information

46. Using Switches to Create VLANs
Virtual local area networks (VLANs)
Network within a network that is logically defined by grouping its devices’ switch ports in the same broadcast domain
Broadcast domain
Combination of ports that make up a Layer 2 segment and must be connected by a Layer 3 device

47. Using Switches to Create VLANs
Figure 6-26: A simple VLAN design

48. Higher-Layer Switches
Switch capable of interpreting Layer 3 data is called a Layer 3 switch
Switch capable of interpreting Layer 4 data is called a Layer 4 switch
These higher-layer switches may also be called routing switches or application switches

49. Routers Multiport connectivity device
Can integrate LANs and WANs running at different transmission speeds and using a variety of protocols
Routers operate at the Network layer (Layer 3) of the OSI Model

50. Router Features and Functions
Modular router
Router with multiple slots that can hold different interface cards or other devices
Figure 6-27: Routers

51. Router Features and Functions
Filter out broadcast transmission to alleviate network congestion
Prevent certain types of traffic from getting to a network
Support simultaneous local and remote activity
Provide high network fault tolerance through redundant components
Monitor network traffic and report statistics to a MIB
Diagnose internal or other connectivity problems and trigger alarms

52. Router Features and Functions
Static routing
Technique in which a network administrator programs a router to use a specified paths between nodes
Dynamic routing
Automatically calculates best path between nodes and accumulates this information in a routing table
Hop
Term used in networking to describe each trip data take from one connectivity device to another

53. Router Features and Functions
Figure 6-28: The placement of routers on a LAN

54. Routing Protocols
To determine the best path, routers communicate with each other through routing protocols
In addition to its ability to find the best path, a routing protocol can be characterized according to its convergence time and bandwidth overhead
Convergence time
The time it takes for a router to recognize a best path in the event of a change or outage
Bandwidth overhead
Burden placed on an underlying network to support the routing protocol

55. Routing Protocols The four most common routing protocols:
RIP (Routing Information Protocol) for IP and IPX
OSPF (Open Shortest Path First) for IP
EIGRP (Enhanced Interior Gateway Routing Protocol) for IP, IPX, and AppleTalk
BGP (Border Gateway Protocol) for IP

56. Brouters and Routing Switches
Bridge router
Also called a brouter
Industry term used to describe routers that take on some characteristics of bridges
Routing switch
Router hybrid that combines a router and a switch

57. Gateways
Combination of networking hardware and software that connects two dissimilar kinds of networks
Popular types of gateways include:
gateways
IBM host gateways
Internet gateways
LAN gateways

58. Chapter Summary
Network interface cards (NICs) come in a variety of types
In addition to network adapters that interface with network cabling, network adapters can be designed for wireless transmission
Installing a NIC involves attaching it to the bus (or port), installing the NIC device drivers, and configuring its settings
Firmware combines software and hardware
An IRQ is the means by which a device can request attention from the CPU

59. Chapter Summary
Repeaters are connectivity devices that perform the regeneration of a digital signal
At its most primitive, a hub is a multiport repeater
A MIB is a collection of data used by management programs to analyze network performance and problems
Bridges resemble repeaters in that they have a single input and single output port, but differ from repeaters because they can interpret the data they transmit

60. Chapter Summary
Switches, like hubs, subdivide a network into smaller logical pieces
A switch running in cut-through mode will read a frame’s header and decide where to forward the data before it receives the entire packet
In store and forward mode, switches read the entire data frame and check it for accuracy before transmitting it
In addition to improving bandwidth, switches can create virtual local area networks (VLANs)

61. Chapter Summary
A router is a multiport device that can connect dissimilar LANs and WANs running at different transmission speeds and using a variety of protocols
To determine the best paths across networks, routers communicate with each other using routing protocols
The networking industry has adopted the term “brouter” to describe routers that take on some characteristics of bridges
Gateways are combinations of networking hardware and software that connect two dissimilar kinds of networks