Module 1 - Networking Fundamentals

Layer 1 of the OSI Model is named "Physical" because it is responsible for defining the physical means of moving data between hardware. This includes cabling, interface cards, and other physical components such as NICs and hubs. It focuses on the transmission and reception of raw data bits over a physical medium.

VLAN Tagging, also known as Frame Tagging, is a process that adds tags inside frame headers to identify the VLAN to which a packet belongs. This helps in distinguishing and managing packets as they travel through trunk links. By assigning a specific tag to each packet, network administrators can ensure that the packets are correctly routed to their respective VLANs, allowing for efficient network management and segregation of traffic. Therefore, the statement "True" is correct.

The correct answer is the Application Layer. This layer of the OSI Model supports application and end-user protocols. It is responsible for allowing programmers to make their programs network aware through the use of Device Operating Systems' Applications Programming Interfaces (API). File transfers, email, and Telnet are examples of activities that occur within this layer.

The correct answer is Network Layer. This layer in the OSI Model is responsible for routing and switching technologies, as well as using the Internet Protocol (IP) to ensure that data is delivered to its intended destination on the network. It is where frames from Layer 2 are transformed into packets, and it is the layer where most routing occurs.

The MAC Address, also known as the Media Access Control Address, is a unique physical address assigned by the NIC (Network Interface Card) manufacturer. It is used to identify network devices, such as computers or routers, on a local network. Each device connected to a network has a different MAC Address, allowing for the identification and communication between devices. The MAC Address is hardcoded into the NIC and cannot be changed, making it a reliable and unique identifier for network devices.

The maximum theoretical data rate per stream achievable under the IEEE 802.11g standard is 54 Mbps. This standard was introduced in 2003 and offered higher data rates compared to its predecessor, IEEE 802.11b. The 54 Mbps data rate is achieved using Orthogonal Frequency Division Multiplexing (OFDM) modulation technique, which allows for higher throughput and better performance in wireless networks. However, it is important to note that the actual data rate experienced by users may be lower due to various factors such as distance, interference, and network congestion.

ICMP, IPv4, IPSec, RIP, and ARP are all protocols commonly found in the Network Layer of the OSI Model. This layer is responsible for logical addressing, routing, and the delivery of data packets across different networks. These protocols operate at the Network Layer to perform tasks such as network addressing, error detection and reporting, security, and routing decisions. Therefore, the correct answer is any variation that includes the term "Network Layer," such as "Network," "Layer 3 Network," or "Layer 3 - Network Layer."

The correct answer is Data Link Layer. This layer of the OSI Model is responsible for transferring data between directly connected nodes in a network. It establishes a direct and reliable point-to-point connection. Switches operate in this layer, and the Ethernet protocol exists within this layer. Information in data packets is encoded and decoded into data frames, which consist of a Link Layer Header followed by a packet within this layer.

Client devices receive the correct VLAN packets because switches restrict the passage of VLANs through specific ports. This means that only certain VLANs are allowed to reach the client devices, while others are blocked. The client devices themselves are not aware of which VLAN they are receiving, as this is managed by the hardware switches.

A POE device, such as an external POE Injector, is commonly known as a midspan device. This means that it is a device that can be added to an existing network infrastructure to provide Power over Ethernet capabilities to devices that do not have built-in POE support. Midspan devices are typically used when there is a need to upgrade or add POE functionality to a network without replacing all the existing network switches. Therefore, the statement "A POE device such as an external POE Injector, is commonly known as a midspan device" is true.

The correct answer is Open System Interconnection Model. The OSI Model is a conceptual framework that standardizes the functions of a communication system into seven different layers. These layers help in understanding and implementing network protocols and technologies. The OSI Model provides a systematic approach to network design and troubleshooting by dividing the communication process into smaller, manageable layers.

Client devices (e.g. PCs or laptops) do not actively block all other VLANs. In fact, client devices are typically unaware of VLANs and are not responsible for filtering or blocking VLAN packets. VLAN filtering and blocking is usually done at the network switch level, where the switch determines which VLAN packets to forward to which ports based on their VLAN tags. Therefore, the correct answer is False.

A router is a network host that reads the source and destination addresses in the packet header and makes decisions about where to forward the packet. It functions as a hardware device that connects dissimilar physical networks, allowing data to be transmitted between them. By analyzing the packet header information, the router determines the most efficient path for the packet to reach its destination, forwarding it accordingly. This enables the router to effectively route data between different networks and ensure proper delivery.

Switches operate at the Data Link Layer of the OSI model. The Data Link Layer is responsible for the reliable transfer of data between nodes on a network. Switches use MAC addresses to forward data packets within a local area network (LAN). They analyze the destination MAC address of incoming packets and use their forwarding table to determine the appropriate port to send the packet to. This layer also handles error detection and correction, ensuring the integrity of data transmission.

The RJ-45 connector used in UTP networks typically terminates 8 wires. The RJ-45 connector is commonly used for Ethernet connections and has 8 pins or positions for wires to be connected. Each pin is assigned to a specific wire in the UTP (Unshielded Twisted Pair) cable, allowing for the transmission of data. Therefore, the correct answer is 8.

These protocols, DNS, DHCP, SSH, HTTP, FTP, and SMTP, are all commonly found in the Application Layer of the OSI Model. The Application Layer is responsible for providing network services to user applications. These protocols are specifically designed to support various application-level functions such as domain name resolution (DNS), dynamic IP address allocation (DHCP), secure remote access (SSH), web browsing (HTTP), file transfer (FTP), and email communication (SMTP). Therefore, the correct answer is Layer 7, Application Layer, or any variation that includes both Layer 7 and Application.

The maximum distance over which POE power can be guaranteed delivery along certified Cat 6 cable is 100 metres. This is because Cat 6 cable is designed to support Ethernet connections up to 1000 Mbps and has a maximum length specification of 100 metres. Beyond this distance, there may be signal degradation and power loss, resulting in unreliable POE power delivery.

The frequency range of the IEEE 802.11g standard is 2.4 GHz. This standard operates in the 2.4 GHz frequency band, which is commonly used for Wi-Fi communication. The 2.4 GHz frequency range allows for a good balance between range and data transfer speed, making it suitable for most wireless networking applications.

The 802.3at Power Sourcing Equipment is capable of delivering a maximum power of approximately 35 W.

Trunk links on switches allow for the transmission of multiple VLANs over a single physical connection. This means that multiple VLANs can be configured on a single port, allowing for efficient use of network resources. Trunk links are commonly used in scenarios where there is a need to carry multiple VLANs between switches, such as in a large network with multiple subnets or in a virtualized environment. By configuring multiple VLANs on a trunk link, network administrators can effectively manage and control the flow of traffic between different VLANs on the network.

Access links on switches are typically used to connect end devices, such as computers or printers, to the network. These links are usually configured with only one VLAN per port. This allows the switch to send and receive traffic for a specific VLAN, ensuring that the connected device is only part of that particular VLAN. By limiting each access link to a single VLAN, network administrators can control and separate traffic between different VLANs more effectively. Therefore, the given answer, "True," is correct.

In Ethernet networks, only one active logical path may exist at any time between any two stations for the network to function properly. This is because Ethernet networks use a single path or link to transmit data between stations. Having multiple active logical paths between stations can lead to collisions and data loss, which can disrupt the network's functioning. Therefore, to ensure proper functioning, Ethernet networks typically have only one active logical path between stations.

The correct answer is Power over Ethernet. The IEEE standard 802.3af defines the specifications for Power over Ethernet (PoE), which is a technology that allows network devices to receive power and data over the same Ethernet cable. This standard enables devices such as IP phones, wireless access points, and network cameras to be powered without the need for separate power cables or outlets.

The explanation for the given answer "False" is that IEEE 802.11ac is a recent Wi-Fi specification that requires specific hardware to support its features. Therefore, not all existing Wi-Fi hardware is automatically compatible with 802.11ac and cannot achieve the new fast speeds without upgrading to compatible hardware.

Spanning Tree Protocol is a network protocol that prevents loops in a network by blocking redundant paths. It ensures that there is only one active path between any two network devices, thus preventing broadcast storms and network congestion. By blocking redundant paths, Spanning Tree Protocol helps to maintain a loop-free and stable network topology.

The maximum power delivered by 802.3af Power Sourcing Equipment is not approximately 48 W. The correct answer is False.

When a Power over Ethernet (POE) device is a Switch, it is commonly referred to as an Endspan. This means that the switch is capable of providing power to connected devices through the Ethernet cable itself, eliminating the need for separate power cables. This is in contrast to a Midspan, which is a separate device that is installed between the switch and the powered devices to provide power. Therefore, the statement is true.

The IEEE 802.11n standard operates in the frequency range of both 2.4 GHz and 5 GHz. This means that devices using this standard can connect to wireless networks in either of these frequency bands. The 2.4 GHz band is commonly used and has a longer range, while the 5 GHz band offers faster speeds but has a shorter range. Having both frequency options allows for more flexibility and compatibility with different types of devices and network environments.

The correct answer is Physical because the Physical layer of the OSI model is responsible for converting the data into bits and transmitting it over the network. This layer deals with the actual transmission of data, including the physical medium, cables, connectors, and electrical signals. It ensures that the data is transmitted reliably and accurately between the computers.

The 802.3af Power Sourcing Equipment is a standard used for Power over Ethernet (PoE) applications. It specifies that the maximum power that can be delivered by this equipment is approximately 15 W. Therefore, the statement "The maximum power delivered by 802.3af Power Sourcing Equipment is approximately 15 W" is true.

MIMO stands for Multiple Input Multiple Output in IEEE 802.11. It refers to a technology that uses multiple antennas at both the transmitting and receiving ends of a wireless communication system. This allows for multiple data streams to be transmitted and received simultaneously, increasing the overall data throughput and improving the system's reliability and performance.

Switches are networking devices that are responsible for moving packets between devices in a network. They receive packets from one device and forward them to the appropriate destination device based on the destination MAC address. This allows for efficient and direct communication between devices in a network. Switches operate at the data link layer of the OSI model and are essential for creating local area networks (LANs) by connecting multiple devices together.

Ports on switches which are configured as Access Links can only be configured with a single VLAN per port. Access Links are used to connect end devices to the switch and allow traffic from only one VLAN to pass through the port. This helps to segregate network traffic and ensure that devices in different VLANs do not interfere with each other. Therefore, the statement that Access Links can be configured with multiple VLANs per port is false.

The given statement is false. The maximum power delivered by 802.3at Power Sourcing Equipment is not approximately 48 W. The actual maximum power delivered by 802.3at Power Sourcing Equipment is 30 W.

The correct answer is Spanning Tree Protocol (STP). STP is a network protocol that prevents undesirable switching loops in a network by creating a loop-free logical topology. It achieves this by dynamically selecting a root bridge and calculating the shortest path to the root bridge for each switch in the network. STP disables redundant links and blocks certain ports to eliminate loops and ensure a single active path between end stations.

To successfully transmit 802.3af POE over standard UTP cable, four cables are required. This is because 802.3af POE requires two pairs of wires for power transmission and the remaining two pairs for data transmission. Therefore, a minimum of four cables are needed to transmit both power and data effectively.

In Australia, the DC voltage supplied via 802.3af or 802.3at is typically 48 Volts.

When terminating a Cat 5 cable to an RJ-45 connector, it is important to use the correct connector for the cable type being used. This ensures compatibility and proper connection. Additionally, the outer sheath of the cable should be secured inside the rear of the connector when crimped to provide stability and prevent damage. All cables should be trimmed neatly and pressed firmly into the very end of the connector before crimping to ensure a secure connection. It is also important to maintain as much of the original twists in the UTP cable as close to the connector as possible to maintain signal integrity. Finally, always test the cable to confirm that all pins are connected correctly for proper functionality.

The maximum theoretical data rate per stream achievable under the IEEE 802.11n standard with 20 MHz wide channels is 72.2 Mbps. This standard supports multiple-input multiple-output (MIMO) technology, which allows for the use of multiple antennas to transmit and receive data simultaneously. The 72.2 Mbps data rate is achieved using a 64-QAM modulation scheme with a coding rate of 5/6, which provides a higher level of data encoding and faster transmission speeds.

Creating VLANs provides added security by separating network traffic into different virtual networks, reducing the risk of unauthorized access and potential data breaches. It also provides segmentation, allowing network administrators to logically divide the network into smaller, more manageable segments, improving network performance and reducing network congestion.

PoE (Power over Ethernet) can be found in two forms of equipment: Powered Device and Power Sourcing Equipment. A Powered Device refers to any device that receives power through the Ethernet cable, such as IP phones, wireless access points, or IP cameras. On the other hand, Power Sourcing Equipment refers to the equipment that provides power to the Powered Devices, such as PoE switches or injectors. These two forms of equipment work together to enable the transmission of power and data over the Ethernet cable.

Enabling channel 12 when some clients don't support it may create a coverage gap for those clients. This means that if channel 12 is enabled and some devices in the network do not support it, those devices will not be able to connect to the network. This could result in a coverage gap where certain devices are unable to access the network or experience poor connectivity. Therefore, it is best practice to disable support for channel 12 in order to ensure consistent and reliable connectivity for all devices in the network.

The protocols typically found in the Application Layer are DHCP, SSH, HTTP, and FTP. ISDN, TCP, ICMP, and SSL are not typically found in this layer. ISDN (Integrated Services Digital Network) is a protocol used for digital transmission of voice, video, and data over traditional telephone lines. TCP (Transmission Control Protocol) is a transport layer protocol responsible for establishing and maintaining a reliable connection between devices. ICMP (Internet Control Message Protocol) is a network layer protocol used for error reporting and diagnostic purposes. SSL (Secure Sockets Layer) is a cryptographic protocol used for secure communication over the internet. These protocols operate at different layers of the network stack and are not typically associated with the Application Layer.

Multicasting in a network offers several benefits. Firstly, individual host machines have the freedom to decide whether they want to participate in a multicast group, allowing for greater flexibility and control. Secondly, multicast traffic is only generated when requested by host machines, minimizing unnecessary network traffic and optimizing bandwidth usage. Lastly, multicast traffic creates efficiency and saves bandwidth by transmitting data only when and where it is needed, reducing network congestion and improving overall performance.