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Router, Switch and Hub

Router

  • A device that connects multiple packet-switched networks and directs data packets to their correct destinations.
  • Enables multiple devices to share an internet connection.
  • Types of Network a router connects:
  • LAN( Local Area Network)
  • WAN( Wide Area Network)
  • It acts like an air traffic controller for data packets making sure they reach the correct destination.
  • It reads the Packet Header, Consults the routing table, forwards the packet.
  • Types of Router: Basics Routers:
  • Wireless Router: Connects to modem via Ethernet and creates a WLAN using radio signals.
  • Connects to modem via Ethernet and forms a LAN using physical cables. Specialized Routers:
  • Core Router: handles high-volume data traffic within large networks.
  • Edge Router: Located at the network boundary, connects internal networks to external ones using BGP.
  • Virtual Router: A software-based router that can act as a backup using VRRP.

Hub

  • It is a networking device that connects multiple hosts in a network, functioning as a multi-port repeater.
  • It operates at Layer 1 (Physical Layer) of the OSI model and facilitates data transfer between devices using either twisted part or fiber optic cables.
  • Hubs do not manage traffic intelligently they simply broadcast data to all connected devices.
  • It functions as multi-port repeater, broadcasting data to all connected devices in half-duplex mode.
  • Comes in 4 to 24 ports and has three types: Active, Passive and intelligent hubs.
  • Advantages or hub:
  • Connectivity: Allows multiple clients to connect and communicate in a network.
  • Performance: Minimal impact on network performance due to its broadcast model.
  • Device Support: Supports different media types and speeds.
  • Area Coverage: Extends network range for better communication.
  • Disadvantages of hub:
  • Collision Domain: Increases the chances of packet collisions within the network.
  • Half-Duplex Mode: Cannot operate in full-duplex data can only be sent or received at a time.
  • Limited Scalability: Cannot efficiently support large networks like token ring.
  • High network Traffic: Does not reduce traffic, leading to congestion.
  • Bandwidth Sharing: All devices share the same bandwidth, slowing down the network.

Switch

  • A switch is a network device that segments networks into subnets or LAN segments.
  • I filters and forwards packets based on MAC addresses.
  • With multiple ports, it examines the destination address and processes data accordingly.
  • It supports unicast, multicast and broadcast communication.
  • Features of Network Switches:
  • Operates at the Data Link Layer of the OSI Model and uses packet-switching techniques for data transfer.
  • Performs error checking before forwarding data and ensures data reaches only the intended device.
  • Supports full-duplex communication and allocated limited bandwidth to each LAN segment.
  • Handles unicast, multicast and broadcast transmissions.

  • Comes with multiple ports for better connectivity.

  • Types of switches:

  • Virtual Switches: Used in Virtual Machine(VM) environment to manage traffic between VMs.
  • Routing Switches: Connect LANs and operate at the Network Layer, enabling routing functionality.
  • Unmanaged Switches: Simple plug-and-play switches used in small networks automatically passing data without manual configuration.
  • Manages Switches: Advanced switches used in large networks and SNMP-based configuration, offering better security and control.
  • Smart Switches: Partially managed switches with some control over data transmission but with limitations compared to fully managed switches.
  • LAN Switches: Also called Ethernet or data switches, they prevent packet collisions by efficiently allocating bandwidth.
  • PoE Switches: Power over Ethernet (PoE) switches that transmit both and power over the same cable, commonly used in Gigabit Ethernet networks.
  • Stackable Switches: Can be connected via a backplane to function as a single logical switch.

  • Modular Switches: Allow the addition of extra modules/cards for better flexibility and scalability.

  • Layer 2 Switch:

  • A layer 2 switch operates at the Data Link Layer (Layer 2) of the OSI model and forwards data based on MAC addresses.
  • It is commonly used in LANs to create separate collision domains and reduce congestion.
  • The switch identifies the correct port using MAC addresses to send data to the appropriate destination device.
  • Layer 3 switch:
  • Combines the functionality of regular switch and a router, operating at both the Data Link Layer and Network Layer of the OSI model.
  • It can route packets between different subnets or VLANs using IP addresses, similar to how router work.

  • This makes Layer 3 switches ideal for large networks, as they provide both fast switching and routing capabilities in a single device.

  • Unmanaged switch:

  • It is a basic plug-and-play network device that automatically enables communication between Ethernet devices.
  • It is typically used in home networks or small businesses where the network design in simple and there’s no need for complex configurations.
  • Unmanaged switches are easy to install and use but lack advanced features or configurations options, making them convenient choice for basic networking needs.
  • Managed switch:
  • A managed switch offers advanced features and greater control over network configurations compared to an unmanaged switch.
  • It allows network administrations to set up, monitor and manage the network for better performance and security.
  • Managed switches support remote management via SNMP(Simple Network Management Protocol) and include features like VLANs, QoS(Quality of Service), and redundancy options, making them ideal for complex and large-scale networks.
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