Untitled Quiz

Introduction & LAN Standards

• The objective of the class is for students to explain the key components of LAN and IEEE 802 models.
• The subtopic is introduction to LAN and IEEE 802 LAN Standard.

Geographical Coverage

• Networks can be classified by their geographical coverage.
• Personal Area Networks (PANs): Devices within 10 meters. Usually include cell phones, tablets, and laptops.
• Local Area Networks (LANs): Cover smaller areas (building, floor, or campus). Examples include Ethernet and token ring.
• Metropolitan Area Networks (MANs): Connect LANs within a campus or metropolitan area. Example includes FDDI.
• Wide Area Networks (WANs): Cover large areas (country, or globe). Examples include the public switched telephone network (PSTN) or the internet.

What is LAN?

• A LAN is a network of computers and other components located relatively close together in a limited area.
• LANs can range in size, from two computers in a home office to hundreds of computers in a large corporation.
• A LAN can be wired or wireless.
• LANs can be used by a small business or large corporate office to connect computers and shared peripherals like printers.

LAN Components

• Computers: Endpoints in the network for sending and receiving data.
• Interconnections: Enable data travel from one point to another.
• Network Interface Cards (NICs): Translate the data from the computer into a format for transmission over the LAN.
• Network Transmission Media: Wired media (unshielded twisted pair [UTP], coaxial, fiber optic) and wireless media (Bluetooth, microwave, satellite, infrared) carry signals between devices.
• Network Devices:
  • Hubs: Aggregation devices (Layer 1 OSI).
  • Ethernet Switches: Aggregation point (Layer 2 OSI) for intelligent frame distribution.
  • Routers: Connect multiple LAN segments (Layer 3 OSI).
  • Access Points: Wireless network devices to enable connection to a local area network.

Protocols

• Protocols govern data transmission over a LAN:
  • Ethernet protocols (CSMA/CD)
  • Internet Protocol (IP) - IPv4, IPv6
  • Address Resolution Protocol (ARP) and Reverse Address Resolution Protocol (RARP)
  • Dynamic Host Configuration Protocol (DHCP)
  • Transmission Control Protocol (TCP)
  • Internet Control Message Protocol (ICMP)

Software

• Network Operating System (NOS): Examples include Microsoft Windows NT 4 and Windows 2000 Server, and Novell NetWare 3.x, 4.x and 5.x.
• Operating Systems: Windows 8 (example)
• Application Software: Examples include MS Office, VBasic, etc.

Revision

• Host name, MAC address, and IP address identify devices on a LAN.
• Local Address is the TCP/IP network address used to access another computer on the same network subnet.
• Host name is a label that identifies a device on a network.
• MAC address (Media Access Control address) is a unique hardware (or physical address) that identifies a device.
• IP address identifies a device on a network or the internet

Host Name | MAC Address | IP Address

• Host Name: A label assigned to a device on a network.
• MAC Address: A hardware or physical address (48-bit hexadecimal) unique to a device.
• IP Address: A unique address that identifies a device on a network or the internet.

The 802 Project Model

• IEEE 802 standards are for the physical components (interface card and cabling) of a network, at the physical and data-link layers of the OSI model.
• A collection of rules covering physical and data-link layers. Applicable to LANs and MANs.
• Aims for multi-vendor interoperability.

Logical Link Control (LLC) | Media Access Control (MAC) Sublayers

• LLC Sublayer: Establishes, controls, sequences, and acknowledges frames for managing data-link communication. Also defines the use of service access points (SAPs). OSI layers above LLC use SAPs for data transfer.
• MAC Sublayer: Manages media access, delimits frames, checks frame errors, and identifies addresses. The lowest sublayer provides shared access. It's directly responsible for transmitting error-free data between computers over the network.

IEEE 802 Standard

• The speed of the network, and the way the NIC accesses and transmits data.
• The types of cables used and the method for accessing the network infrastructure.
• The NICs and drivers used to implement the network.
• Picking the right protocol at the data-link layer is important.

IEEE 802 Categories

• The LAN standards created by the 802 committees can be broken into 16 different categories.

Ethernet Explanation

• Ethernet uses CSMA/CD (carrier sense multiple access/collision detection) for transmitting data packets on a network.
• The physical layer is important for hardware like repeaters, cables, and network interface cards (i.e., 100BaseTX or 10BaseT indicating cable type).
• It determines cable length and the desired network topology.

IEEE 802.3 Popular Versions

• IEEE 802.3 is the original standard for 10Base-5 bus topology using thick coaxial cable.
• IEEE 802.3a uses thin coaxial cable (10Base2).
• IEEE 802.3i uses twisted-pair cable (10Base-T).
• IEEE 802.3u uses twisted-pair for 100BASE-TX, 100BASE-T4, and 100BASE-FX.
• IEEE 802.3j is the standard for Ethernet over fiber (10BASE-F).

Comparison Between Ethernet and LAN

• Ethernet is a prevalent packet-switched LAN, using bus or star topology. LANs use bus, star, or ring topologies.
• Ethernet control is decentralized; LAN control is centralized.
• Ethernet uses guided media; LANs use guided and non-guided media for transmission.
• Ethernet reliability is lower than LANs.
• Ethernet has limitations during transmission; LANs do not have limitations.

IEEE 802.11

• Defines standards for wireless networks.

802.11 a | b | g | n | ac | ax

• Different generations of Wi-Fi, with varying speeds, ranges, and capabilities.
• Some standards might be backward compatible (i.e.: 2.4 GHz).
• Also include features like beamforming, MIMO, OFDM, and other specifications.

Exercise

• Question 1: Correct answer is A (WiFi 5)
• Question 2: Correct answer is A (2.4 GHz)
• Question 3: Correct answer is D (all above)
• Question 4: Correct answer is not provided.
• Question 5: Correct answer is D (I, II and IV).

Which of the following statement is correct about IEEE 802.3 standard

• Correct answers are I and II

Which frequency for IEEE 802.11g standard?

• 2.4 GHz.

The most suitable IEEE 802 standard?

• IEEE 802.3

Which of the following is TRUE about 802.3u standard?

• Correct answers are III and IV

VLAN Technologies

• VLAN (Virtual LAN): A logical grouping of network devices and users that share a physical LAN but are isolated from each other.
• Allows for network segmentation, organizational management via traffic isolation, unique IP addressing ranges within a VLAN.
• VLANs improve network scalability, security, and ease of network management.

Broadcast Domain

• Broadcast domain encompasses the devices within a network segment that receive broadcast messages.
• Devices connected to the same network segment have access to the same broadcast domain.
• A routed network will have multiple broadcast domains.

Collision Domain

• Collision domain relates to the physical network segment of devices sharing a common transmission medium.
• Collision is the simultaneous attempts at sending data within a segment, which causes the packets to collide (causing losses and delays).
• Hub environments have a single collision domain; bridges or switches divide the network into multiple collision domains, improving efficiency by eliminating collisions within the segment.

Virtual Trunk Protocol (VTP)

• VTP is a Cisco protocol used to synchronize VLAN information among network switches.
• VTP Server, VTP Client, and VTP Transparent (different modes in a switch)

VTP Pruning

• Reducing traffic on trunk links and optimizes bandwidth use by filtering out unnecessary broadcast and unknown unicast frames from switches.
• VTP pruning is enabled by default, which results in optimizing the efficiency of the network.

EtherChannel

• Combining physical network links into one logical channel, enhancing the bandwidth, load balancing, and redundancy among network devices.

EtherChannel Modes

• PAgP (Protocol for Aggregating the Port): A proprietary Cisco protocol for EtherChannel.
• LACP (Link Aggregation Control Protocol): An open standard protocol for EtherChannel used by most vendors.
• On (ON mode): Forces the creation of an EtherChannel without any negotiation protocol.

EtherChannel Requirements

• All ports in an EtherChannel must use the same duplex and speed settings.
• All ports must use the same VLAN configuration.
• All ports must have the same switchport mode (access or trunk).

Other

• Various other topics and features related to VLANs and network technologies were covered in the provided presentation materials.
• Many specifics of implementation commands were illustrated.