THE BLOG

Networking Basics - OSPF Theory ccie r/s ccna r/s ccnp r/s Mar 18, 2021

 

In my latest training video, I cover the theory of Open Shortest Path First (OSPF) routing protocol.

 

OSPF is the most popular interior gateway protocol used today. In this...

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OSPF Advanced Concepts - Part 4 ccie r/s ccna r/s ccnp r/s Sep 24, 2019

In the previous part of our OSPF series, we examined options for manually filtering routes. As we wrap up our look at advanced OSPF topics, we'll discuss default routes, and compare OSPFv2...

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OSPF Advanced Concepts - Part 3 ccie r/s ccna r/s ccnp r/s Sep 10, 2019

In our previous blog post, we examined how OSPF can automatically filter routes through the use of special areas and LSA Types. But what about your options for manually filtering...

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OSPF Advanced Concepts - Part 2 ccie r/s ccna r/s ccnp r/s Aug 27, 2019

Last time, we began our look at advanced OSPF topics with the configuration of backbone and non-backbone areas. In this blog post, we'll look at the creation of more specific area types.

Stubby...

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OSPF Advanced Concepts - Part 1 ccie r/s ccna r/s ccnp r/s Aug 13, 2019

The time has arrived to tackle some of the more advanced (and interesting) features of the Open Shortest Path First routing protocol. We begin by examining the configuration and verification of the...

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OSPF Basic Concepts - Part 3 ccie r/s ccna r/s ccnp r/s Jul 30, 2019

Before we move on to more advanced topics, we'll wrap up this OSPF Basics series in Part 3. Here we'll examine LSA types, area types, and virtual links.

OSPF LSA Types

Link State Advertisements...

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OSPF Basic Concepts - Part 2 ccie r/s ccna r/s ccnp r/s Jul 23, 2019

In the previous blog post, we looked at a few fundamental OSPF concepts, including neighbor and adjacency formation. As we continue through the basics of OSPF, this post will examine...

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OSPF Basic Concepts - Part 1 ccie r/s ccna r/s ccnp r/s Jul 09, 2019

The OpenShortest Path First (OSPF) dynamic routing protocol is one of the most beloved inventions in all of networking, widely adopted as the Interior Gateway Protocol (IGP) of choice for many...

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Fundamentals of Border Gateway Protocol (BGP) - Part 6 ccie r/s ccna r/s ccnp r/s Jun 04, 2019

This post is the 6th and final in a series of Border Gateway Protocol (BGP) posts. If you missed any of the first five parts, here are the links:

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Fundamentals of Border Gateway Protocol (BGP) - Part 5 ccie r/s ccna r/s ccnp r/s May 21, 2019

This post is the 5th in a series of Border Gateway Protocol (BGP) posts. If you missed any of the first four, here are the links:

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Fundamentals of Border Gateway Protocol (BGP) - Part 4 ccie r/s ccna r/s ccnp r/s May 07, 2019

This post is the 4th in a series of Border Gateway Protocol (BGP) posts. If you missed any of the first three, here are the links:

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Fundamentals of Border Gateway Protocol (BGP) - Part 3 ccie r/s ccna r/s ccnp r/s Apr 08, 2019

This post is the 3rd in a series of Border Gateway Protocol (BGP) posts. If you missed either of the first two, here are the links:

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Fundamentals of Border Gateway Protocol (BGP) - Part 2 ccie r/s ccna r/s ccnp r/s Mar 12, 2019

Part 1 of our blog series on Border Gateway Protocol (BGP) gave you an overview of  BGP and then delved into BGP message types and neighbor states. Now, in this post, you'll learn about one of...

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Fundamentals of Border Gateway Protocol (BGP) - Part 1 ccie r/s ccna r/s ccnp r/s Jan 29, 2019

One of the most intimidating topics for Cisco certification candidates in the Route/Switch track is Border Gateway Protocol (BGP). To help remove the FUD (Fear, Uncertainty, and Doubt) surrounding...

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Route Redistribution- Part 4 ccie r/s ccnp r/s Nov 29, 2018

This post is the fourth in a series of posts on route redistribution. If you haven't yet read the first three, here are the links:

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Route Redistribution- Part 3 ccie r/s ccnp r/s Nov 06, 2018

 

This post is the third in a series of posts on Route Redistribution. If you didn’t yet read the first two, here are the links:

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Route Redistribution- Part 2 ccie r/s ccnp r/s Oct 30, 2018

In a previous post, we considered the need for route redistribution, and we also took a look at some configuration examples. This posts builds on that previous configuration and discusses how...

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Route Redistribution - Part 1 ccie r/s ccnp r/s Sep 25, 2018

Introduction to Route Redistribution 

Until there is one routing protocol to rule them all, there is a need to have multiple routing protocols peacefully coexist on the same network. Perhaps...

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5 SDN Concepts You've Gotta Know ccie r/s ccna r/s ccnp r/s Nov 28, 2017

I recently did a Facebook Live session covering 5 major Software Defined Networking (SDN) concepts. If you missed the live session, or just want to watch a replay, check out this video.

We...

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OSPF Route Filtering ccie r/s ccnp r/s Nov 14, 2017

Let's say you have one or more IP routes that you don't want appearing in a router's IP routing table. The reason might be for security or for router performance, as a couple of...

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Configuring Quality of Service Using MQC ccie collaboration ccie r/s ccna collaboration ccna r/s ccnp collaboration ccnp r/s Oct 17, 2017

The Need to Know MQC in a World of Automation

These days, Quality of Service (QoS) can be configured relatively easy. If we’re using the APIC-EM as a network controller to manage our routers...

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Fundamentals of Auto Smartports ccie r/s ccna r/s ccnp r/s Sep 26, 2017

The Auto Smartports feature available on Cisco Catalyst switches allows a port to automatically detect that you’ve attached a device it can recognize (e.g. a Cisco IP Phone, wireless access...

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BGP Route Reflectors ccie r/s ccnp r/s Aug 15, 2017

A BGP-speaking router, by default, will not advertise an Internal BGP (iBGP) route to an iBGP neighbor. One solution for this issue is to create a full mesh of neighborships within an Autonomous...

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Understanding EIGRP Part 6 (Router ID and Neighborship Requirements) ccie r/s ccna r/s ccnp r/s Feb 23, 2017

This blog post wraps up our series on Understanding EIGRP by discussing two final topics:

  • The EIGRP Router ID
  • EIGRP's Neighborship Requirements

Let's begin our discussion by considering the...

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Understanding EIGRP – Part 5 (Static Neighbors) ccie r/s ccna r/s ccnp r/s Feb 05, 2017

Typically, an EIGRP-speaking router dynamically discovers its neighbors, by sending multicast Hello messages. However, there is an option to statically configure those neighbors, and communicate...

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Fundamentals of the Internet of Things (IoT) career success ccie r/s ccna r/s ccnp r/s Feb 02, 2017

It's another one of those buzzwords we're hearing a ton these days, the Internet of Things, or IoT for short.

But what exactly is it, and how's it going to impact us as networking professionals?...

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Understanding EIGRP – Part 4 (Passive Interfaces) ccie r/s ccna r/s ccnp r/s Jan 31, 2017

Sometimes, we might want a router interface to participate in an EIGRP routing process (in order to advertise that interface's network) without that interface sending out EIGRP Hello messages....

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Intermediate System to Intermediate System (IS-IS) Routing Protocol Fundamentals ccie r/s ccna r/s ccnp r/s Jan 20, 2017

In our Cisco routing and switching studies, we commonly study routing protocols such as RIP, OSPF, EIGRP, and BGP. However, there's a very scalable, fast converging, link-state routing...

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Understanding EIGRP – Part 3 (EIGRP Timers) ccie r/s ccna r/s ccnp r/s Jan 09, 2017

Once of EIGRP’s claims to fame is its fast convergence in the event of a link failure. However, one thing that might slow down this convergence is timer configuration. That's the focus of...

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What is Cisco IWAN (Intelligent WAN)? ccie r/s ccnp r/s Jan 05, 2017

One of the buzzwords you hear a lot in our industry these days is Cisco IWAN. But, what exactly is Cisco IWAN, and what can it do for us? That's what you'll learn in this video.

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Understanding EIGRP – Part 2 ccie r/s ccna r/s ccnp r/s Dec 02, 2016

In the first blog post in our Understanding EIGRP series, we were introduced to EIGRP’s features, in addition to a basic configuration example, and a collection of verification commands....

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Understanding EIGRP – Part 1 ccie r/s ccna r/s ccnp r/s Nov 18, 2016

I used to work as a Network Design Specialist at Walt Disney World, in Florida. Their massive network contained over 500 Cisco routers (and thousands of Cisco Catalyst switches). What was the...

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Your Framework for Cisco Exam Preparation ccie collaboration ccie r/s ccna collaboration ccna r/s ccnp collaboration ccnp r/s Sep 20, 2016

You want to get your first (or next) Cisco certification, but do you have a specific preparation strategy, or are you just winging it? If you do have a structured framework you’re confidently...

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BPDUGuard: A Spanning Tree Protocol Enhancement ccie r/s ccna r/s ccnp r/s Aug 30, 2016

Yet another new topic on the new CCNA R/S v3 exam is BPDUGuard, which is an enhancement to Spanning Tree Protocol (STP) available on our Cisco Catalyst switches. Specifically, BPDUGuard can help...

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Configuring VRF-Lite ccie r/s ccnp r/s Jun 07, 2016

You’re probably familiar with the concept of virtualization, where you can run multiple virtual servers on a single physical server. However, did you know that you can run multiple virtual...

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Fundamentals of VRF-Lite ccie r/s ccnp r/s Feb 24, 2016

Have you ever used some sort of virtualization software (e.g. vmware) to get multiple virtualized servers running on a single physical server? It’s a great way to save resources, by...

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Cisco Learning Labs – Review ccna r/s ccnp r/s Jan 12, 2016

How do you get hands-on experience when you’re preparing for your CCNA R/S or CCNP R/S certifications? One option is using the Cisco Learning Labs. You can check out my review here.

Links to...

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Troubleshooting Route Redistribution ccie r/s ccnp r/s May 15, 2015

This video shows you how to troubleshoot a route redistribution scenario with multiple redistribution points.

This video is a sample from my new CCNP R/S v2 Complete Video Course Library (which...

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Troubleshooting OSPF Neighborships ccie r/s ccnp r/s Apr 23, 2015

In this new video, you’ll learn common issues that can prevent an OSPFv2 neighborship from forming. Then, you’ll walk through a sample OSPF troubleshooting scenario.

 

This video...

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Gateway Load Balancing Protocol (GLBP) ccie r/s ccnp r/s Jan 01, 2015

Happy New Year!

If one of your goals for 2015 is to earn your CCNP R/S certification, you might want to check out a new video I did.


The video discusses the theory of GLBP, a First Hop...

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BGP Peer Groups ccie r/s ccnp r/s Nov 26, 2014

This video from my ROUTE Complete Video Course demonstrates how BGP Peer Groups can help conserve a router’s CPU resources if the router is doing BGP route filtering with multiple BGP...

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