1. Guide to Networking Essentials, 6th Edition
Chapter 2: Network Hardware Essentials

2. Objectives In this chapter, students will learn:
Basic operation of network repeaters and hubs
The purpose of network switches
The operation of wireless access points
the basic operation of network interface cards
The function of routers
Copyright © 2012 Cengage Learning. All rights reserved. 2

3. Intro; Repeaters; Hubs PP. 61-66
Section 1.1
Intro; Repeaters; Hubs PP
Copyright © 2012 Cengage Learning. All rights reserved.

4. Network Repeaters and Hubs
Early networks didn’t use interconnecting devices
Severely limited network size
Total cable length and number of computers
Copyright © 2012 Cengage Learning. All rights reserved.

5. Network Repeaters and Hubs
Repeats signal
Used to extend networks
A repeater receives bit signals generated by NICs and other devices, strengthens them, and then “repeats” them to other parts of the network
Enables you to connect computers whose distance from one another would make communication impossible
Two ports
Copyright © 2012 Cengage Learning. All rights reserved.

6. Network Repeaters and Hubs
A repeater extends the length of a network
Copyright © 2012 Cengage Learning. All rights reserved.

7. Hub (Multiport Repeater)
Hub – a multi-port repeater
Signaling Process:
Receives signal from one port
Cleans the signal - Filters out electrical noise
Regenerates the signal to full strength
Transmits the signal to all other ports
Copyright © 2012 Cengage Learning. All rights reserved.

8. Hubs (Multiport Repeaters)
A multiport repeater or hub
Copyright © 2012 Cengage Learning. All rights reserved.

9. Hubs and Network Bandwidth
Network Bandwidth – The amount of data that can be transferred in an interval.
Usually measured in bits per second (bps)
Speeds range from 10 Mbps up to 10 Gbps
Bandwidth sharing – when all computers connected to the hub must share the amount of bandwidth the hub provides
Causes collisions
Copyright © 2012 Cengage Learning. All rights reserved.

10. Hub Indicator Lights Power, link status, network activity, collisions
Uplink port – port used to connect two hubs together or hub to a switch
Simulation 3: Basic operation of a hub
Copyright © 2012 Cengage Learning. All rights reserved.

11. Comprehension Check
Enables you to connect computers whose distance from one another would make communication impossible.
Repeater
Networking device that sends data out all ports
Hub
Two things that hubs do to improve data quality
Cleans and regenerates signal going out all ports
Copyright © 2012 Cengage Learning. All rights reserved.

12. Comprehension Check Name the four lights found on a network hub
Power, link status, network activity, collisions
Network Bandwidth
The amount of data that can be transferred in an interval
How is network bandwidth measured?
bps (Mbps or Gbps)
Copyright © 2012 Cengage Learning. All rights reserved.

13. Section 1.2 Switches and WAPs PP. 66-79
Copyright © 2012 Cengage Learning. All rights reserved.

14. Network Switches Looks like a hub Inside a LAN
Reads data a frame at a time
Gets MAC address from each frame
Forwards the message to only the port tied to that MAC address.
Copyright © 2012 Cengage Learning. All rights reserved.

15. Network Switches Switches maintain a switching table
Copyright © 2012 Cengage Learning. All rights reserved.

16. Network Switches Steps of switch operation: 1. Receives a frame.
2. Reads the source and destination MAC addresses.
3. Looks up the destination MAC address in its switching table.
4. Forwards the frame to the port where the computer owning the MAC address is found.
5. The switching table is updated with the source MAC address and port information.
Simulation 4: Basic operation of a switch
Copyright © 2012 Cengage Learning. All rights reserved.

17. Switches and Network Bandwidth
Each port gets dedicated bandwidth
Can operate in full-duplex mode
Can send and receive data simultaneously
Hubs only half-duplex
Switches are the preferred device because of these advantages
Copyright © 2012 Cengage Learning. All rights reserved.

18. Switch Indicator Lights
Link status indicators
Activity indicators
May have full-duplex or half-duplex mode indicators
Uplink Port – Used to connect switches
Expand network
Some switches have a dedicated uplink
Copyright © 2012 Cengage Learning. All rights reserved.

19. Wireless Access Points
Wireless Access Point - Operate similarly to a hub without wires.
Wireless Router - combines the functions of an AP, a switch, and a router
Small businesses and home networks
Wireless LANs usually attached to wired networks
Copyright © 2012 Cengage Learning. All rights reserved.

20. Wireless Access Points
A wireless router
Copyright © 2012 Cengage Learning. All rights reserved.

21. Basic AP Operation All stations hear all data being transmitted
Receiving device sends an acknowledgment back to the sending device to indicate successful reception
Request to send (RTS) - optional
Workstation requesting permission to transmit to AP
Clear to Send (CTS) - optional
AP response saying it OK to transmit
Copyright © 2012 Cengage Learning. All rights reserved.

22. Wireless APs and Network Bandwidth
All the extra chatter required to send data in a wireless network slows communication
The effective bandwidth is about half of effective bandwidth found on physical networks
Most APs operate from 11Mbps to several hundred Mbps
11 Mbps is b which is outdated
Copyright © 2012 Cengage Learning. All rights reserved.

23. Comprehension Check
Which networking appliance reads frames and sends each frame out only one port
Switch
How do switches (typically) know what port to send out a message.
Switching table
Can send and receive data simultaneously (term)
Full-duplex
Copyright © 2012 Cengage Learning. All rights reserved.

24. Comprehension Check A special port used to connect switches
Uplink Port
A wireless device that is similar to a hub
Wireless Access Point (WAP)
Message sent to the AP when a workstation wants to transmit.
Request to send (RTS)
Message sent to workstation from AP indicating it is OK to send the message
Clear to Send (CTS)
Copyright © 2012 Cengage Learning. All rights reserved.

25. Lab 1.2 Setup a Basic Network: To put on same LAN: Try
One computer per team
Use a single switch to put them on the same LAN
To put on same LAN:
Use Windows search feature to access the “networking and sharing center”
Select “Change adapter settings” in the upper left corner.
right-click - “Local area connection” and select “properties”
Enter password
From the Networking tab select
“Internet Protocol Version 4 (TCP/IPv4)”
Press the “properties” button
Set your own IP address by pressing the “use the follo
Try
IP Address
Subnet Mask
Copyright © 2012 Cengage Learning. All rights reserved.

26. Section 1.3
NICs PP
Copyright © 2012 Cengage Learning. All rights reserved.

27. Network Interface Cards
Connect computer to medium
Incoming messages: Receives bit signals and assembles them into frames
Outgoing messages: receive packets from network protocol
Creates frames by adding MAC addresses and error check
Converts frame into bit signals and transmits them
Copyright © 2012 Cengage Learning. All rights reserved.

28. Network Interface Cards
A NIC handles incoming data from the network medium
Copyright © 2012 Cengage Learning. All rights reserved.

29. Network Interface Cards
NIC required to attach to networking medium
Networking medium might be copper wire, fiber-optic cable, or airwaves
Most NICs are built into a computer’s motherboard
May use more than one NIC (especially servers)
It is important to know how to install a new NIC
Copyright © 2012 Cengage Learning. All rights reserved.

30. Network Interface Cards
A NIC handles outgoing data to be sent to the network medium
Copyright © 2012 Cengage Learning. All rights reserved.

31. NICs and MAC addresses All NICs have a unique MAC address
MAC address is stored in read-only memory (ROM) on the NIC
MAC Address = Two 24-bit hexadecimal numbers
24-bit manufacturer ID called OUI
24-bit serial number assigned by the manufacturer
48-bit address expressed in 12 hexadecimal digits: B-1A-C4
Copyright © 2012 Cengage Learning. All rights reserved.

32. The NIC as a Gatekeeper
NIC validates the MAC addresses of incoming frames
Three ways a frame may be accepted by a NIC:
Match the MAC address of the NIC
Broadcast frame (ff-ff-ff-ff-ff-ff)
If NIC is in permiscuous mode
Unicast Frame – A frame addressed to only one computer on the LAN
When the destination MAC address matches the NICs MAC address, it’s a unicast frame
Copyright © 2012 Cengage Learning. All rights reserved.

33. The NIC as a Gatekeeper
Broadcast Frame – A frame designed to be sent to all computers on a network.
Typically: ff-ff-ff-ff-ff-ff
Promiscuous mode – turns off the gatekeeper functions and enables the NIC to process all frames it sees
Simulation 5: How a NIC works
Copyright © 2012 Cengage Learning. All rights reserved.

34. NIC Indicator Lights
NICs have indicator lights to show status information
Usually a link status indicator and an activity indicator
The link light is usually green when connected to a network
Some NICs support multiple speeds
Usually a separate light for each speed so that you can determine at what speed the NIC is connected to the hub or switch
In other cases the light is a different color for each speed, such as amber for 100 Mbps and green for 1000 Mbps
Copyright © 2012 Cengage Learning. All rights reserved.

35. Selecting a NIC NICs commonly built into motherboard
An additional NIC or a faster NIC may need to be installed
When selecting a NIC you need to select correct bus interface
PCI-Express is most common
The NIC driver (software) must be available for your OS
For servers, consider a NIC with onboard memory and multiple ports that performs faster
Copyright © 2012 Cengage Learning. All rights reserved.

36. NIC Drivers Most OSs ship with NIC drivers
NICs ship with drivers for the most common OSs
If the OS has a suitable driver available, it is installed automatically
After installation, Windows 7 shows your installed NIC as a “Network Connection”
In Windows, each connection is assigned a name as in “Local Area Connection”, “Local Area Connection 2”
You can rename these
Copyright © 2012 Cengage Learning. All rights reserved.

37. NIC Drivers
Copyright © 2012 Cengage Learning. All rights reserved.

38. Wireless NICs NICS use SSID to join the network.
Choose Wireless NICs based on the type of wireless AP
Typical Wireless Standards: n; ac
Older standards: a, b, and g
Service Set ID (SSID) - the name assigned to the wireless network
NICS use SSID to join the network.
Typically need to enter a security key or UID and PSWD
Copyright © 2012 Cengage Learning. All rights reserved.

39. Comprehension Check What is required to attach a computer to a network
Network Interface Card (NIC)
What does the NIC do with bit signals coming from network?
Assembles them into frames
What identification code is tied to a NIC
MAC address
Three ways a frame may be accepted by a NIC:
Match the MAC address of the NIC
Broadcast frame (ff-ff-ff-ff-ff-ff)
If NIC is in permiscuous mode
Copyright © 2012 Cengage Learning. All rights reserved.

40. Comprehension Check
NIC setting that the gatekeeper functions and enables the NIC to process all frames it sees
Promiscuous mode
What color is the link light when successfully connected to a network
Green
Consider a NIC with onboard memory and multiple ports that performs faster if the computer is a
Server
The name assigned to the wireless network
Service Set ID (SSID)
Copyright © 2012 Cengage Learning. All rights reserved.

41. Lab 1.3 To Do Disable integrated NIC and add a new one to a junker
Work with two of the servers in promiscuous mode
Start using Wireshark now
Evaluate “Packet tracer”
Lookup networking symbols
Should we just use Cisco standards?
Are there other standards we could use?
Copyright © 2012 Cengage Learning. All rights reserved.

42. Section 1.4
Routers PP
Copyright © 2012 Cengage Learning. All rights reserved.

43. Routers Most complex networking device
Connect LANs together to create an internetwork
Copyright © 2012 Cengage Learning. All rights reserved.

44. Routers
Routers - devices that enable multiple LANs to communicate with one another by forwarding packets from one LAN to another
Copyright © 2012 Cengage Learning. All rights reserved.

45. Routers vs Switches Routers Switches Connect LANS
Connect computers within a LAN
IP addresses (Logical)
MAC addresses (Physical)
Work with packets
Work with frames
Do not forward broadcasts
Do forward broadcasts
Use routing tables
Use switching tables
Copyright © 2012 Cengage Learning. All rights reserved.

46. Routers Connect LANs It is possible to overload a LAN with computers
Broadcast traffic can really affect this
The next slide shows 3 different groups of users and 3 different servers all connected by switches
Copyright © 2012 Cengage Learning. All rights reserved.

47. Routers Connect LANs
Since they are connected by switches, they are all part of the same LAN and all broadcast traffic will be heard by all devices
Copyright © 2012 Cengage Learning. All rights reserved.

48. Routers Connect LANs
The picture on the next slide shows a better solution for the previous network
The administrator groups users and servers together based on their department or function
Copyright © 2012 Cengage Learning. All rights reserved.

49. Routers Connect LANs
The router is used to create 3 separate LANs in order to contain broadcast traffic and facilitate more effective communication in each department LAN
Copyright © 2012 Cengage Learning. All rights reserved.

50. Routers Create Broadcast Domains
The scope of devices to which broadcast frames are forwarded is called a broadcast domain
Each router interface in a network creates another broadcast domain
Copyright © 2012 Cengage Learning. All rights reserved.

51. Routers Work with IP Addresses and Routing Tables
Routers maintain routing tables composed of IP network addresses and interface pairs to determine where to forward packets on an internetwork
Copyright © 2012 Cengage Learning. All rights reserved.

52. Routers Work with IP Addresses and Routing Tables
What happens when a router isn’t connected to the network the packet is addressed to?
The following slide shows what the routing table would look like on each router between the source and destination networks
Copyright © 2012 Cengage Learning. All rights reserved.

53. Routers Work with IP Addresses and Routing Tables
Copyright © 2012 Cengage Learning. All rights reserved.

54. Routers Work with IP Addresses and Routing Tables
Default route — where to send a packet when the router doesn’t have an entry in its routing table
Network unreachable — Message sent when the network can’t be found and there is no default route
Default gateway — the IP address of the computer’s router
Simulation 6: Router operation in a simple internetwork
Copyright © 2012 Cengage Learning. All rights reserved.

55. Chapter Comprehension Check
Network repeaters and hubs take incoming bit signals and
repeat those signals out all connected ports
Switches use _______ ______ to determine which MAC address can be found on which port
switching tables
A central device in a wireless network and perform a similar function to hubs
Access points
Create and mediate the connection between the computer and network medium
Network interface cards
Copyright © 2012 Cengage Learning. All rights reserved.

56. Chapter Comprehension Check
Connect LANs to one another and forward packets from one LAN to another
Router
Routers use what address type to route messages between networks
IP Address
Unlike hubs and switches, routers do not forward
broadcast frames
The IP address of the computer’s router
Default Gateway
Copyright © 2012 Cengage Learning. All rights reserved.

57. Comprehension Check
Used by the router to determine to which network to route packets
Routing Table
Where to send a packet when the router doesn’t have an entry in its routing table
Default route
Copyright © 2012 Cengage Learning. All rights reserved.

58. Lab As a class brainstorm labs that may make sense to do here.
Copyright © 2012 Cengage Learning. All rights reserved.