UNIT 5: Functioning of Network Devices and Network Management System

UNIT 5: Functioning of Network Devices and Network Management System

This unit focuses on understanding the functioning of various network devices and the network management system. We will discuss the working of network devices such as NIC, hub, switch, router, and WiFi devices, and also explore the network management system and the SNMP protocol in detail.

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5.1. Functioning of Network Devices

Network devices are the backbone of any network. These devices help in sending, receiving, and managing data between different parts of a network.

5.1.1. NIC (Network Interface Card)

NIC is a hardware device that connects a computer to a network. It is responsible for sending and receiving data over the network.

• Functionality:
  • NIC sends and receives data packets over the network.
  • It uses the MAC (Media Access Control) address, which helps in identifying devices in the network.
• Diagram:

  [Computer] ---- NIC ----> [Network] ----> [Switch/Router]
  

5.1.2. Hub

A Hub is a basic networking device that connects multiple devices in a network and sends data to all the connected devices. It works as a "repeater" by broadcasting the data to all connected devices.

• Functionality:

  • Hub broadcasts the data packet to all the ports without checking which device the data is meant for.
  • It can affect connection quality and data security since all devices receive the same data.

• Diagram:

  [Computer 1]       [Hub]      [Computer 2]
        |------------------------|
  

5.1.3. Switch

A Switch is a more advanced network device that directs data packets specifically to the devices they are meant for. Unlike a hub, a switch is smarter because it uses the MAC address to send data only to the intended device.

• Functionality:

  • The switch uses MAC addresses to forward the data packets.
  • It helps control network traffic and reduces congestion compared to a hub.

• Diagram:

  [Computer 1]       [Switch]    [Computer 2]
        |-----------------------|
  

5.1.4. Router

A Router is a device that connects two or more networks and directs data packets between them. It helps in directing traffic between different networks, such as between a local network and the internet.

• Functionality:

  • Routers use IP addresses to forward data packets between networks.
  • It helps in routing traffic and ensuring data reaches the correct network.

• Diagram:

  [Computer] -----> [Router] -----> [Internet]
  

5.1.5. WiFi Devices

WiFi devices are used to send and receive data over wireless networks. WiFi routers or access points transmit data wirelessly to devices on the network.

• Functionality:

  • WiFi devices transmit and receive data wirelessly between devices and the network.
  • They use radio waves to communicate between devices and the network.

• Diagram:

  [Computer] <-----> [WiFi Router] <-----> [Internet]
  

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5.2. Network Management System (NMS) and SNMP Protocol

A Network Management System (NMS) is a software-based solution used to monitor, manage, and control network resources. It ensures the proper functioning of the network and resolves issues as they arise.

5.2.1. SNMP (Simple Network Management Protocol)

SNMP is a protocol used to monitor and control network devices such as routers, switches, servers, etc. It works with NMS to gather information from network devices and manage them.

• Functionality:

  • SNMP is used to retrieve information from network devices, monitor their status, and manage them.
  • It uses the Media Access Control (MAC) address to interact with network devices.

• SNMP Structure:

  • Manager: The device that collects data from network devices.
  • Agent: The software running on network devices that communicates with the SNMP Manager.

• Key SNMP Commands:

  • GET: Retrieves information from a network device.
  • SET: Changes settings on a network device.
  • TRAP: An alert sent by a network device to notify the manager about a specific event.

• Diagram:

  [SNMP Manager] <---> [Router] <---> [Switch] <---> [Server]
  

5.2.2. Examples of SNMP Protocol

1. GET Request:
   • An SNMP manager sends a GET request to fetch data from a device like a switch or router.
2. SET Request:
   • An SNMP manager sends a SET request to modify settings on a device, such as changing the device's IP address or other configurations.

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Summary

• Network Devices: These devices, such as NIC, hub, switch, router, and WiFi devices, are crucial for the operation of a network. They help in sending, receiving, and managing data across the network.

• Network Management System (NMS): NMS is used to monitor and manage the performance of network devices. The SNMP protocol plays a vital role in retrieving data from network devices and controlling them.

By properly utilizing these devices and protocols, the network can be made more efficient and reliable.