draft.

Virtual LAN (VLAN)

Virtual Trunking Protocol (VTP)

• Document ID: 10558: Understanding VLAN Trunk Protocol (VTP)
  • VLAN Trunk Protocol (VTP) reduces administration in a switched network. When you configure a new VLAN on one VTP server, the VLAN is distributed through all switches in the domain. This reduces the need to configure the same VLAN everywhere. VTP is a Cisco-proprietary protocol that is available on most of the Cisco Catalyst series products.
• Document ID: 98155: Troubleshooting VLAN Trunk Protocol (VTP)
  • This document provides information on how to troubleshoot VLAN Trunk Protocol (VTP).

Private VLAN

•  Private VLANs Revisited

EtherChannel

• Document ID: 12025: System Requirements to Implement EtherChannel on Catalyst Switches
  • Each section of this document contains the system requirements to implement EtherChannel on the platforms that the document describes. This document also contains a table that describes suggestions for EtherChannel modes between Catalyst switches.

Chapter 3 STP

Spanning Tree Protocol (STP)

• Document ID: 5234: Understanding and Configuring Spanning Tree Protocol (STP) on Catalyst Switches
  • Spanning Tree Protocol (STP) is a Layer 2 protocol that runs on bridges and switches. The specification for STP is IEEE 802.1D. The main purpose of STP is to ensure that you do not create loops when you have redundant paths in your network. Loops are deadly to a network.
• Document ID: 12013: Understanding Spanning-Tree Protocol Topology Changes
  • When you monitor Spanning-Tree Protocol (STP) operations, you may be concerned when you see topology change counters that increment in the statistics log. Topology changes are normal in STP. But, too many of them can have an impact on network performances.
• Understanding STP Convergence, Part I and Understanding STP Convergence, Part II or from the same author Understanding STP and RSTP Convergence
  • In this post we are going to look into STP convergence process. Many people have perfect understanding of STP, but yet face difficulties when they see questions like “How many seconds will it take for STP to recover connectivity if a given link fails?”.
• Document ID: 19120: Understanding and Tuning Spanning Tree Protocol Timers
  • This document describes the Spanning Tree Protocol (STP) timers and the rules to follow in order to tune the timers.
• Document ID: 28943: Troubleshooting STP on Catalyst Switches Running Cisco IOS System Software
  • This document provides guidelines to use Cisco IOS® software to troubleshoot issues with Spanning-Tree Protocol (STP). There are specific commands which apply to the Catalyst 6500/6000 only; however, you can apply most of the principles to any Cisco Catalyst switch that runs Cisco IOS software.
    

STP features

• Document ID: 10575: Understanding and Configuring the Cisco UplinkFast Feature
  • UplinkFast is a Cisco specific feature that improves the convergence time of the Spanning-Tree Protocol (STP) in the event of the failure of an uplink.
• Document ID: 12014: Understanding and Configuring Backbone Fast on Catalyst Switches
  • Backbone fast is a Cisco proprietary feature that, once enabled on all switches of a bridge network, can save a switch up to 20 seconds (max_age) when it recovers from an indirect link failure. After a quick review of some Spanning-Tree Protocol (STP) basics, you can see the exact failure scenario to which backbone fast applies and how to configure it for Catalyst switches that run both CatOS and Cisco IOS® software.
  • Describes also what to do if switch receives Inferior BPDU

Configuring STP

• Catalyst 3560 Software Configuration Guide, Release 12.2(58)SE
• Catalyst 3550 Multilayer Switch Software Configuration Guide, 12.1(8)EA1
•  

 Rapid STP

• Document ID: 24062: Understanding Rapid Spanning Tree Protocol (802.1w)
  • The 802.1D Spanning Tree Protocol (STP) standard was designed at a time when the recovery of connectivity after an outage within a minute or so was considered adequate performance. With the advent of Layer 3 switching in LAN environments, bridging now competes with routed solutions where protocols, such as Open Shortest Path First (OSPF) and Enhanced Interior Gateway Routing Protocol (EIGRP), are able to provide an alternate path in less time.
    

Multiple STP

• Document ID: 24248: Understanding Multiple Spanning Tree Protocol (802.1s)
  • Multiple Spanning Tree (MST) is an IEEE standard inspired from the Cisco proprietary Multiple Instances Spanning Tree Protocol (MISTP) implementation. This document assumes that the reader is familiar with Rapid STP (RSTP) (802.1w), as MST heavily relies on this other IEEE standard.
  •  
• MSTP Tutorial Part I: Inside a Region
  • Before we begin with MSTP (Multiple Spanning Trees Protocol), I would like to note that this tutorial is going to be is divided in two parts. The first part describes how MSTP works inside a single region (the definition of the term will follow later). The second part is dedicated to MSTP region interaction with other regions and different STP protocols (IEEE STP, RSTP and Cisco PVST+).
• MSTP Tutorial Part II: Outside a Region
  • This post continues the previous article dedicated to MSTP operations inside a single region. Before reading any further, make sure you read and fully understand the first part of MSTP overview: MSTP Tutorial Part I: Inside a Region. The information there is critical to understand the new post.

 Chapter XY Securing L2

Monitoring SPAN and RSPAN

Chapter 5: Implementing high availability in a Campus Environments

• Cisco Nonstop Forwarding with Stateful Switchover Deployment Guide

Chapter 6: Securing …

Blocking port

• Document ID: 23563: Unicast Flooding in Switched Campus Networks

  • This document discusses possible causes and implications of unicast packet flooding in switched networks.

Notes:

show tech -> Output Interpreter