Author: renjithbs

  • IEEE 802.11 standards

    Wireless LAN (WLAN) based on IEEE 802.11 standards uses different types of Service Sets to define how devices communicate within a wireless network. These service sets specify the architecture and functionality of the network. Below are the key types: 1. Basic Service Set (BSS) 2. Extended Service Set (ESS) 3. Independent Basic Service Set (IBSS)

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  • Introduction to Wireless LANs (WLANs)

    What is a Wireless LAN (WLAN)? A Wireless Local Area Network (WLAN) is a type of network that allows devices to connect and communicate wirelessly over a short distance using radio waves. It eliminates the need for physical cables, providing flexibility and mobility within a defined area such as a home, office, or public space.

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  • Introduction to Wireless Networks

    Wireless networks are communication systems that use radio waves or infrared signals to transmit data without requiring physical connections (such as cables or wires). They have become an integral part of modern communication, enabling mobility, flexibility, and scalability in various environments, from homes and offices to large-scale industrial applications. Types of Wireless Networks Key Components

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  • πŸ›  Real-World Troubleshooting of Spanning Tree Issues

    Spanning Tree Protocol (STP) helps prevent Layer 2 loops, but misconfigurations and failures can still cause network outages. Here’s how to troubleshoot common STP issues effectively. πŸ” 1️⃣ Issue: Network Loop / Broadcast Storm 🚨 Symptoms:βœ… High CPU utilization on switches.βœ… MAC address table fluctuates rapidly.βœ… End devices lose connectivity intermittently.βœ… Excessive broadcast/multicast traffic in

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  • Spanning Tree Protection Mechanisms

    To prevent switching loops, unauthorized topology changes, and misconfigurations, Cisco offers several Spanning Tree Protocol (STP) protection mechanisms: 1️⃣ BPDU Guard (Prevents Unauthorized Switches) βœ… Purpose: Disables a port if it receives a BPDU.βœ… Use Case: Prevents unauthorized switches from connecting to PortFast-enabled ports.🚨 Applies to: Access ports (where only end devices should be connected).

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  • Spanning Tree Enhancements: PortFast, UplinkFast, and BackboneFast

    Cisco introduced these STP enhancements to speed up convergence and improve network reliability. Let’s break them down! 1️⃣ PortFast (Edge Port) βœ… Purpose: Bypasses STP states (Listening & Learning) to immediately forward traffic.βœ… Use Case: For end-user devices (PCs, printers, servers) to reduce boot time delays.🚨 Warning: DO NOT enable on switch-to-switch links! It can

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  • PVST vs. Rapid PVST

    Cisco switches support Per-VLAN Spanning Tree (PVST) and Rapid Per-VLAN Spanning Tree (Rapid PVST) to prevent Layer 2 loops. Let’s compare them! 1️⃣ What is PVST? (Per-VLAN Spanning Tree) βœ… Cisco proprietary version of STP.βœ… Runs one STP instance per VLAN.βœ… Based on IEEE 802.1D (classic STP) β†’ Slow (50 sec convergence).βœ… Each VLAN can

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  • Real-World STP Troubleshooting Scenario

    Scenario: Network Loop and High CPU Usage Company ABC has a redundant Layer 2 network using Rapid Spanning Tree Protocol (RSTP). Users report network slowdowns, high latency, and intermittent connectivity. The network administrator notices that CPU usage on the core switch is spiking to 90%. Symptoms Observed: βœ… High CPU usage on switches.βœ… Excessive broadcast

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  • How Spanning Tree Protocol (STP) Works

    1️⃣ The Problem: Why Do We Need STP? In a redundant Layer 2 network, multiple paths exist between switches to improve reliability. However, this can cause switching loops, leading to: 🚨 Broadcast Storms – Frames endlessly circulate, consuming bandwidth.🚨 MAC Table Instability – Switches receive frames on multiple interfaces, confusing MAC address learning.🚨 Multiple Frame

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  • Spanning Tree Protocol (STP) Port States

    STP operates by transitioning ports through different states to avoid loops while still allowing network connectivity. Each port in STP can be in one of the following states: 1️⃣ Disabled State πŸ”΄ Not part of STP operation πŸ”Ή Command to Disable a Port: Switch(config)# interface GigabitEthernet0/1Switch(config-if)# shutdown 2️⃣ Blocking State 🟑 Prevents network loops πŸ”Ή

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