Homework
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DEFINITIONS
Ethernet LANs - These LANs connect nearby devices using copper UTP or fiber-optic cables
802.3 - standard cable used to connect the two Ethernet LANs
Fast Ethernet - 100-Mbps 1995
Gigabit Ethernet - 1000-Mbps late 90’s
MAC address - A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment
Autonegotiation - An Ethernet procedure by which two connected devices choose common transmission parameters, such as speed, duplex mode, and flow control.
MAC address table - a table which lists which MAC address is connected to which port
Ethernet frame – payload of an Ethernet packet
Wired LAN – a local area network that is hard wired using Ethernet cables
Wireless LAN – local area network that is wireless using the 802.11 standard
Star topology - network consists of one central switch, hub or computer, which acts as a conduit to transmit messages.
10BASE-T - Twisted-pair cables for the physical layer of an Ethernet computer network.
100BASE-T - A networking standard that supports data transfer rates up to 100 Mbps, fast Ethernet
1000BASE-T - 1000BASE-T is Gigabit Ethernet (1 gigabit is 1000 megabits per second) on copper cables
10GBASE-T - 10 Gigabit Ethernet, 10 Gbit/s connections
Metro Ethernet - Type of WAN service
Token Ring - Type of LAN technology that uses a special three-byte frame called a token that travels around the ring. Token-possession grants the possessor permission to transmit on the medium.
LAN Edge – Local area network that has the ability to distribute data to multiple users connected to the network.
Wireless-only LAN edge - Local area network that has the ability to distribute data to multiple users connected to the network only using wireless technology.
Wired/wireless LAN edge - Local area network that has the ability to distribute data to multiple users connected to the network using both wireless and hard wired technology.
Media Access Control - (MAC) technology provides unique identification and access control for computers on an Internet Protocol (IP) network.
Shorthand name (IEEE) – More descriptive way of naming different types of Ethernet connections.
Error detection - Ethernet node performs a process to tell whether any of the other bits changed values during transmission. If they have it is an error and they are discarded. Edge switch - An edge switch is a switch located at the meeting point of two networks.
Ethernet broadcast address - A broadcast address is a logical address at which all devices connected to a multiple-access communications network are enabled to receive datagrams.
Duplex - The duplex setting on a single link determines whether the nodes can or cannot send at the same time.
Half duplex - Nodes must take turns Full duplex - Nodes can send at any time
Straight-through cable - Straight-through cable is a type of twisted pair copper wire cable for local area network (LAN) use for which the RJ-45 connectors at each end have the same pinout. Most commonly used to connect devices of different types, such as a computer to a router (or network switch or hub).
Crossover cable - Type of Ethernet cable used to connect computing devices together directly. It is most often used to connect two devices of the same type: e.g. two computers
Ethernet header - The header features destination and source MAC addresses
Ethernet trailer - The contents of the trailer include both user information and system information
Destination MAC address – Where packets are being sent
Source MAC address - Where packets are coming from
Flooding - In a network, flooding is the forwarding by a router of a packet from any node to every other node attached to the router except the node from which the packet arrived.
Forwarding - To forward traffic (in the form of IP packets) between the sites Learning - LAN switches can learn their MAC address tables two ways: The engineer can type the details to give the MAC address table information to the switch. The switch can learn the information by reading the frames that pass through the switch.
Unknown unicast frame - When a switch tries to forward a frame destined to some unicast MAC address, but the switch does not list that destination MAC in its MAC table
Broadcast frame - Any frames with destination MAC address FFFF.FFFF
Known unicast frame - If the switch lists the destination MAC in its MAC address table
Universal MAC address – MAC address unique across the entire Earth/universe

REVIEW QUESTIONS
1. c. Token Ring
2. d. 802.11 LANs
3. b. 4 Gbps
4. a. 1000BASE-LX, MM fiber, 550 meters
5. b. The links could use any Ethernet LAN standard.
6. e. None of the answers is correct.
7. a. 802.3ab
8. a. Overall downward trend for computer technology prices over time c. The introduction of 1000BASE-T products into the market
9. a. Autonegotiation works on the switch–to–PC A link, causing PC A to run at 100 Mbps.
c. Autonegotiation fails to work on the switch–to–PC B link, causing the switch to run at 10 Mbps.
10. a. PC A uses full duplex as the result of the autonegotiation process working. c. Switch port G2 uses half duplex because autonegotiation fails, making the switch use the default duplex setting.
11. c. UTP typically supports a maximum cable length of 100 meters across all UTP standards at all speeds
12. b. A UTP link from an edge switch to a distribution switch c. A UTP link between two distribution switches
13. c. The Type field identifies the data as an IP packet.

14. a. Any nodes in the branch LAN that receive this frame use the FCS field to help detect errors.
c. The Preamble and SFD fields both come before the Destination Address field in the header.
15. a. 48 bits in length
16. a. The IEEE b. Ethernet vendors
17. d. The OUI
18. c. Forwards the frame out port G4 only
19. a. Floods the frame out ports G1, G2, and G4
20. b. SW1 received a frame sent to MAC address 0000.1234.5678 in port G4.