1. Unit 5: Chapter 5, Ethernet LANs
NT1210 Introduction to Networking
Unit 5:
Chapter 5, Ethernet LANs 1

2. Class Agenda 1/19/16 Learning Objectives
Lesson Presentation and Discussions.
Midterm Exams is in the next class.
Lab Activities will be performed in class.
Assignments will be given in class.
Break Times. 10 Minutes break in every 1 Hour.
Note: Submit all Assignment and labs due today.

3. Objectives Define Ethernet LAN concepts.
Evaluate the advantages and disadvantages of Ethernet technology in LANs.
Analyze the advantages of using Layer 2 devices to segment LANs.
Troubleshoot wired LANs for connectivity and performance. 3

4. Defining Ethernet LANs
Ethernet: Originally developed as LAN technology
Connect end-user devices in one site with devices relatively close by
Each LAN site connects to WAN via router
Ethernet standards kept growing to support faster speeds and longer cabling distances
Modern Ethernet networks might be LANs or WANs
Companies generally own their own LANs 4

5. Principles of Ethernet
Ethernet was first developed by Xerox Corporation. The original intent was to create a technology to allow computers to connect with laser printers.
From this humble beginnings, Ethernet rose to be used to interconnect such devices as computers, printers, wireless access points, servers, switches, routers, video-game systems, and more.

6. Defining Ethernet LANs
Late 1970s: End of proprietary standards
LAN standards all start with IEE Standard 802 6
Table 5-1

7. Characteristics defined by the IEEE 802 standards committee
Bandwidth
Access
CSMA/CD technology
Channel Bonding
Topology Options
Media Types
Analogy:
Imagine that you are driving around in Europe in an American made car, and suddenly you hear a really bad sound from one of the wheels. You stop at the next service station to have it checked out and are told that your brakes are worn out and need to be replaced. You can see that the service station has a lot of brake inventory so you think this is not going to take long to fix. Sadly, the owner tells you that he cannot help you because he only has metric based brake pads and they will not fit on American cars. Had you known this could happen, you might have brought some spare parts with you. Such is the need to understand the importance of standards.
The reason for the existence of the IEEE is to create and ratify standards for products that consume or transmit electrical power. They do not deal with the quality of the finish product like Underwriter’s Labs do, but rather they focus on the standards used to create safe and effective usage of electricity and related technologies including signaling standards.
In the world of networking these standards all begin with the number 802 and are followed by a dot and some number and letter combination. While the Net+ exam requires you to know these for answering questions, fortunately, the real world only needs you to really know a few. They are:
802.1 (especially as it relates to switching technologies)
802.3 Ethernet CSMA/CD
Wireless
On a lesser level, you will want to be familiar with these:
802.5 Token Ring CSMA/CA (decreasing in importance)
802.9 Integrated Voice and Data (increasing in importance)
Network Security (increasing in importance)

8. Characteristics defined by the IEEE 802 standards committee
Bandwidth
Access
CSMA/CD technology
Channel Bonding
Topology Options
Media Types
Analogy:
Imagine that you are driving around in Europe in an American made car, and suddenly you hear a really bad sound from one of the wheels. You stop at the next service station to have it checked out and are told that your brakes are worn out and need to be replaced. You can see that the service station has a lot of brake inventory so you think this is not going to take long to fix. Sadly, the owner tells you that he cannot help you because he only has metric based brake pads and they will not fit on American cars. Had you known this could happen, you might have brought some spare parts with you. Such is the need to understand the importance of standards.
The reason for the existence of the IEEE is to create and ratify standards for products that consume or transmit electrical power. They do not deal with the quality of the finish product like Underwriter’s Labs do, but rather they focus on the standards used to create safe and effective usage of electricity and related technologies including signaling standards.
In the world of networking these standards all begin with the number 802 and are followed by a dot and some number and letter combination. While the Net+ exam requires you to know these for answering questions, fortunately, the real world only needs you to really know a few. They are:
802.1 (especially as it relates to switching technologies)
802.3 Ethernet CSMA/CD
Wireless
On a lesser level, you will want to be familiar with these:
802.5 Token Ring CSMA/CA (decreasing in importance)
802.9 Integrated Voice and Data (increasing in importance)
Network Security (increasing in importance)

9. Defining Ethernet LANs
Three Important IEEE LAN Standards
Working Group
Common Reference
Purpose
802.2
Logical Link Control
Defines features in common across Ethernet, Token Ring, and others
802.3
Ethernet
Defines features specific to Ethernet
802.5
Token Ring
Defines features specific to Token Ring
Key Original IEEE 802 LAN Standards 9
Table 5-1

10. Other Standards
802.1 (especially as it relates to switching technologies)
802.3 Ethernet CSMA/CD
Wireless
On a lesser level, you will want to be familiar with these:
802.5 Token Ring CSMA/CA (decreasing in importance)
802.9 Integrated Voice and Data (increasing in importance)
Network Security (increasing in importance)

11. Defining Ethernet LANs: LAN vs. WAN
Many Telcos today offer WAN services to customer site uses an Ethernet standard. The LANs at each site can still use Ethernet, but the WAN links also use Ethernet.
Ethernet LAN vs. Ethernet WAN 11
Figure 5-1

12. Defining Ethernet LANs: Wired vs. Wireless
Wired: Ethernet
Wireless: Wireless LANs
Comparing the Combined Hybrid LAN to a Wireless-Only LAN Edge 12
Figure 5-3

13. Ethernet Origins
IEEE 802.3, in general this in is interchangeable with the term Ethernet.
In the early days, it was called 10BASE5.
10 = 10 Mbps (10 million bits per second)
BASE = Baseband, one signal on the line at a time.
5 = 500 meters of cable max
The cable use was RG-6, became known as thicknet.

14. Defining Ethernet LANs: Ethernet Bit Rates
10BASE-5: Standard that used thick coaxial cabling (thicknet) with bus topology
10BASE-2: Standard that used thinner coaxial cable (Thinnet) with bus topology
10BASE-T: Ethernet standard deployed in 1990 used UTP cabling with star topology
Ethernet Standards Dates, Speeds, and Common Names 14
Figure 5-5

15. Defining Ethernet LANs: Distances
Standard
Shortcut Family Name
Specific Shortcut Name
Year
Cabling
Max Length1
802.3z
1000Base-X
1000Base-LX
1998 MM
550 m
1000Base-SX SM
5 Km1
802.3ab
1000BASE-T
1999
UTP (4 pair)
100 m
Gigabit Ethernet Standards and Cable Lengths 15
Table 5-2

16. Defining Ethernet LANs: Standard Names
Original IEEE
IEEE Shorthand Name
Informal Name(s)
Speed
Typical Cabling
802.3i
10BASE-T
Ethernet
10 Mbps
UTP
802.3u
100BASE-T
Fast Ethernet (Fast E)
100 Mbps
802.3z
1000BASE-X
Gigabit Ethernet (Gig E, GbE)
1000 Mbps
Fiber
802.3ab
1000BASE-T
802.3ae
10GBASE-X
10 GbE
10 Gbps
802.3an
10GBASE-T
802.3ba
40GBASE-X
40GbE (40 GigE)
40 Gbps
100GBASE-X
100GbE (100 GigE)
100 Gbps
Ethernet Naming Summary 16
Table 5-4

17. LANs: Topologies
Modern Ethernet LANs use a star topology (physical topologies refers to the shape of the network). In a simple Ethernet LAN, all the devices connect to a single LAN switch. If you spread the devices out to all points on the compass, it looks a little like a star.
Star Topology in an Ethernet LAN Compared to a Drawing of a Sun (Star) 17
Figure 5-7

18. Duplex Auto-Negotiation
Duplex setting on link determines whether to use half- duplex or full-duplex
Devices can negotiate duplex setting with auto- negotiation
Modern LANs use full duplex, but if older hubs exist on network, links have to auto-negotiate
History of Half and Full Duplex 18

19. Building Ethernet LANs: Distance Considerations
UTP links: Maximum 100 meters
Multimode links: Several hundred meters (3-6)
Single mode links: Several kilometers (30-60) 19

20. Building Ethernet LANs: UTP Pinouts
Straight-through Cables: Used to connect 2 devices (e.g., PCs and switches)
Use wire pairs 1, 2 and 3, 6
100BASE-T Transmit and Receive Logic, PC to Switch, with Straight-through Cable 20
Figure 5-15

21. Building Ethernet LANs: UTP Pinouts
Crossover Cables: How the wire pairs communicate
Crossover Cable for 10BASE-T and 100BASE-T 21
Figure 5-16

22. Building Ethernet LANs: UTP Pinouts
Crossover Cables: TIA cabling standards specify which color pair to put in each position in connectors on each end of cable
T568A on one end, and T568B on the other.
TIA Pinout Standards T568A and T568B to Create a Crossover Cable 22
Figure 5-17

23. Break Take 15 23

24. Exploring Ethernet: MAC Address
IEEE defines MAC addresses as 48-bit numbers usually written in hexadecimal (hex)
Each hex digit represents 4 bits (MAC address = 12 hex digits)
Examples of how MAC address expressed A A A 24

25. Exploring Ethernet: MAC Address
Universal MAC address: Permanent address unique across all networks
Uses 2-part format:
Organizationally Unique Identifier (OUI): Code registered to vendor; first half of MAC address
Vendor assigned: Unique serial number chosen by vendor; second half of MAC address
IEEE Organizationally Unique Identifier (OUI) and Unique MAC Addresses 25
Figure 5-20

26. Exploring Ethernet: MAC Address
IEEE Organizationally Unique Identifier (OUI) and Unique MAC Addresses 26
Figure 5-20

27. Exploring Ethernet: LAN Switching
Example of how a switch forwards frames
Example of how a switch forwards frames using 4 PCs: A, B, C, and D
PC A sends a frame destined for PC D (MAC address 0000.DDDD.DDDD)
Switch's port identifiers with the switch's MAC address table find the location of PC D on the network through its MAC address
Explanation of Graphic:
PC A's NIC builds a frame with the destination address of 0000.DDDD.DDDD and sends the frame
SW1 receives the frame, compares the destination MAC address to the MAC table where it finds an entry that lists G4 as the port for that MAC address’ device.
MAC table entry on SW1
SW1 forwards the unchanged Ethernet frame out its G4 port to PC D (destination)
Switch Forwarding Decision: Single Switch 27
Figure 5-21

28. ARP
The Address Resolution Protocol (ARP) is used to resolve a logical (IP) address to a physical (MAC) address.
This protocol is used often when new routes are needed or a new IP address is encountered by your network device where traffic needs to be routed.

29. Exploring Ethernet: Switch Learning
Switches build MAC address tables two ways
Entries manually typed into MAC address table
Switch learns MAC addresses by reading frames that pass through it
SW1 Learns the MAC Address of PC A 29

30. LAN Troubleshooting Ping and Traceroute Arp ping Netstat, nbtstat
Ipconfig, ifconfig,
Nslookup

31. Questions? Comments? 31

32. Unit 5 Assignment Unit 5 Assignment 1: Exploring LAN Switches
Unit 5 Assignment 2: Ethernet Local Area Networks Review
Unit 5 Research Project 1: Chapter 6 Mind Maps
(Instructor example)

33. Unit 5 Lab Unit 5 Lab 5.1: LAN Standards
Unit 5 Lab 5.2: MAC and IP Addresses
Unit 5 Lab 5.3: Finding Network Settings
Unit 5 Lab 5.4: Basic Network Troubleshooting

34. Reading Assignment Odom, Chapter 5: Ethernet LANs
Richardson, Lab Manual Chapter 5
Midterm Exams will be held in the next class