New Skills

New Training: Troubleshooting Cisco Etherchannel and LAG Ports

by Team Nuggets
New Training: BGP Foundation Concepts picture: A
Published on February 22, 2021

In this 5-video skill, CBT Nuggets trainer Jeremy Cioara covers common issues that can occur with EtherChannel (LAG) interfaces and the troubleshooting methods you can use to mitigate them. Gain an understanding of LACP, PAgP, and manual EtherChannel configuration concepts. Cover LACP show commands and features. Watch this new Cisco training.

Watch the full course: Cisco CCNP Enterprise Core

This training includes:

  • 5 videos

  • 1 hour of training

You’ll learn these topics in this skill:

  • Introduction to Troubleshooting Cisco EtherChannel and LAG Ports

  • EtherChannel Review and Base Configuration

  • Critical LACP Show Commands

  • Additional LACP Features

  • Troubleshooting Static and Dynamic EtherChannel and LAG Ports

What is Port Aggregation Protocol (PAgP)?

Port Aggregation Protocol (PAgP) is a protocol for aggregating Ethernet switch ports into an EtherChannel. Unlike Link Aggregation Control Protocol (LACP), which is an open standard specified by IEEE 802.3ad, PAgP is a proprietary Cisco protocol. This means that you can only use PAgP on Cisco switches or switches that have been licensed to support PAgP. Another difference between the two protocols is that LACP can support a cross-stack EtherChannel and PAgP cannot.

PAgP has two modes. In Desirable mode, the device initiates the creation of an EtherChannel by sending a set of frames to another device. In Auto mode, it only receives these frames from another device. These two modes are the equivalent of Active and Passive modes in LACP, respectively.

A limitation of PAgP is that the physical ports that make up the aggregation group must reside on the same device. Though some Cisco devices can overcome this through a Virtual Switching System (VSS).

Recommended Articles