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One command that had a fairly long history first with the PIX Firewall and now the ASA is the shun command. In this post we’ll examine this command’s history, why it’s useful, and its new-found resurgence in threat detection implementation.

If you’re in IT, you’ve likely heard the saying, “In technology, the only thing constant is change itself,” and boy is that right! For technical companies, if you are not moving forward, then you’re falling behind. There is no such thing as standing still! A perfect example of this mindset is in Cisco’s evolution of video conferencing and telepresence.

In light of the recent tragic events in Haiti, it might be a good time to review some of the requirements for a well designed Uninterruptible Power Source (UPS) to be included in all of our critical network installations. As a CCNA, we are called upon to help maintai...

Interior Gateway Routing Protocol (IGRP) was a Cisco-proprietary Distance-Vector (D-V) classful routing protocol - basically an improved version of RIPv1. Like other D-V protocols, each IGRP router periodically flooded its routing table, but it differed from RIP in two ways. First, RIP’s advertisement interval was thirty seconds but IGRP’s was ninety seconds, which allowed IGRP to scale to larger networks than RIP. Second, RIP used a simple hop count metric, but IGRP’s more sophisticated metric was based on minimum path bandwidth and total path delay, with options to include link reliability and interface loading.

In 2013, Cisco released their Software Defined Networking (SDN) solution for the data center known as Cisco Application Centric Infrastructure (ACI). For many years, the networking industry has been asking for an approach to configuring networking devices more efficiently than having to individually configure each and every router and switch.

Moving data from one networked device to another requires several different functions. Each function has its own protocol or protocols that define how it is accomplished. Also, the process of delivering data from one device to another can vary. The main factor in data delivery is determining whether the two devices are directly connected or remotely connected.

Moving data from one networked device to another requires several different functions. Each function has its own protocol or protocols that define how it is accomplished. Also, the process of delivering data from one device to another can vary. The main factor in data delivery is determining whether the two devices are directly connected or remotely connected.

Like it or not, Internet of Things (IoT) is upon us. There are a number of factors that will impact its adoption rate, and the inevitable privacy (or lack of) discussions will likely happen sooner than later. This is going to change the world as we know it, in many cases for the better. But we will need to keep an eye on the extent to which it invades our personal lives if it is going to be the positive force it has the potential to be.

Yes, there’s big money in AWS Certification, which tends to outpace other cloud certification salaries, but there’s more to the cloud than dollars and cents.

Cisco Access Control Lists (ACLs) are used in nearly all product lines for several purposes, including filtering packets (data traffic) as it crosses from an inbound port to an outbound port on a router or switch, defining classes of traffic, and restricting access to devices or services. Knowing how to design, configure, and troubleshoot ACLs is required for all network engineers working within a Cisco network.

While the Internet uses IP addresses assigned by an Internet authority such as the American Registry for Internet Numbers (ARIN), there are too few of these numbers to uniquely identify the millions of computers and computing devices in the world. Therefore, most enterprises use private addresses which allow them to identify the aforementioned computers. Of course, these IP numbers cannot be allowed on the Internet because all private networks use the same ones so there would be vast overlapping of addresses, and the addresses are not compliant anyway. Therefore, it is necessary to change the identity of a private host to a legal public host. This process is called Network Address Translation (NAT) and may be implemented on Cisco firewall products and Cisco routers. The firewall device(s) at the Internet demarcation point is by far the more popular way to implement NAT, but routers are used in small offices or small-to-medium-sized networks in which a separate firewalling solution is not possible or affordable. The focus of this paper is on the router-based NAT solution.

As IT departments struggle with skills gaps and businesses attempt to recovery economically from the COVID-19 pandemic, these 10 IT skills are essential to drive success. Job roles in these areas pay well, but decision-makers are struggling to find qualified candidates. If you’re looking to make an IT skills investment or start a new career path this year, these are the areas to consider.

Telepresence is a set of technologies that allow video conferencing in such a way that the user feels as if they are actually at the remote site. Cisco sells a variety of platforms in the telepresence space supporting up to three 65” high definition video displays,...

Switches play a vital role in moving data from one device to another. Specifically, switches greatly improve network performance, compared to hubs, by providing dedicated bandwidth to each end device, supporting full-duplex connectivity, utilizing the MAC address table to make forwarding decisions, and utilizing ASICs and CAM tables to increase the rate at which frames can be processed.

Instructor John Harmon continues his explanation of subnetting by showing how subnet masks can be used to sub-divide networks.

Instructor John Harmon explains subnetting using binary numbers and decimal conversions.

You may have noticed that it’s the dynamic routing protocols that get all the glory. Since I like rooting (routing?) for the underdog, let’s talk about static routes! As you may recall, a router has three methods for learning a route. A route can appear in the routi...

Subnetting is a complicated topic that has confused students for a very long time. However, subnetting is an important topic for many different certifications with various vendors, including Cisco. In the real world environment, people are used to just punching in the numbers in many of the free subnet calculators that are readily available on the internet. For exam purposes, you still have to do this in a very fast manner since many exams are time-based and you don't have the luxury of spending those precious minutes on any single question. This Cisco training whitepaper will solve some of those age-old and complicated subnetting puzzles.

Learn how Docker makes it easy to update, test and debug software with this white paper and gain foundational knowledge about Dockerfile, Docker images and containers.

Certifications are the most common way in IT to prove you have the skills to solve various technical and business challenges. In this article, I'll address a range of skill sets. For each certification listed, I've included what the certification measures, the requirements to obtain it.

Take charge of your Cisco network devices with Python programming As a network engineer, you might wonder why there’s any need for you to learn Python. After all, network automation is clearly where the industry is headed. And there are many tools that allow yo...

Internet Protocol (IP) routing protocols have one primary goal: to fill the IP routing table with the current best routes it can find. The goal is simple, but the process and options can be complicated. Routing protocols define various ways that routers chat among th...

According to the OSI layer concept, routing, or best path selection, takes place on Layer 3 and is based on the logical address. In this post, we want to discuss some of the points in that statement.

According to the OSI layer concept, routing, or best path selection, takes place on Layer 3 and is based on the logical address. In this post, we want to discuss some of the points in that statement.

In the previous discussion on QoS, the uses of Per-Hop Behaviors DiffServ to mark packets were identified and discussed in detail. Today’s post will identify the mechanisms to implement QoS. The five main categories of tools used to implement QoS are as follows. Cl...

Learn how to calculate QOS Bandwidth Percent vs Bandwidth Remaining Percent using a Cisco-defined formula. Read on for answers and examples from the experts at Global Knowledge!

In this hour-long webinar, Global Knowledge instructor John Barnes will guide you through implementing Cisco private VLANs. He will review VLANs and 802.1q, and he will discuss private VLAN fundamentals and operation, covering primary VLANs and secondary VLANs. He will cover VLAN mapping and discuss using private VLANs between multiple switches. He will also provide a use case example.

Global Knowledge Course Director and Lab Topology Architect Joey DeWiele, a specialist in Unified Communications, explains presence.

What is PBR? Policy-Based Routin (PBR) is the process of using a route map to match on something more than the destination and then defining the path out of the router based on those conditions. PBR could match on destination only, but typically we would match on more. PBR is considered to be an exception to the RIB and is looked at before examining the RIB.

Policy-based routing (PBR) provides network administrators with agility and flexibility to better manage traffic. With carefully architected policies, you can optimize how segments of your network process data, as well as how bandwidth is managed for business-critical applications.

The Global Site Selector (GSS) leverages the Domain Name System (DNS) to provide clients with reliable and efficient content services. Domain to IP address mapping is performed with consideration for availability, location, and load of content servers. Using the GSS in combination with Cisco’s Content Services Switch (CSS), Cisco’s Catalyst 6000 Content Switching Module (CSM), or Cisco’s Application Control Engine (ACE) allows users to create Global Server Load Balancing (GSLB) networks.

Understand the Cisco Security technology and certification training portfolio. This overview will cover the courses needed to prepare for the CCNA Security and CCNP Security certifications. You will also learn about recommended skills-focused courses covering SourceFire technologies, the ASA security solution, and the ISE access control and authentication platform.

Understand the Cisco Collaboration technology and certification training portfolio. This overview will cover the courses needed to prepare for the CCNA Collaboration and CCNP Collaboration certifications. You will also learn about recommended skills-focused courses covering basic and advanced Unified Communications Manager administration.

A video covering our Cisco Unified Communications courses - ACUCW1 & ACUCW2 - by Global Knowledge Course Director and Lab Topology Architect Joey DeWiele, a specialist in Unified Communications.

Now that we are moving towards IPv6, the logical move would be to also run OSPF for that protocol suite, which makes sense and reduces the learning curve for implementation and support. But, that would mean that you have to run two OSPF processes — one for IPv4 unicast and one for IPv6 unicast. That means two sets of policies have to be applied, including security for OSPF itself. Running OSPFv3 for both IPv4 and IPv6 reduces the number routing protocols and the configuration that goes with that. It makes it easier to implement policy in a consistent way for both protocol suites.

As cybersecurity threats continue to be a top concern facing organizations today, the Information Technology (IT) Governance team must stay abreast in assuring that the organization is protected. The IT Governance team must continually evaluate the risks to the organization and put in place Processes, Procedures and Technologies to protect the assets of the organization.  

Looking ahead at new and emerging certifications provides insight into the areas deemed valuable in the IT industry. If you are an early adopter or in a position where you need to show that you have the bleeding-edge expertise of a technology, this list of recent and upcoming certifications is for you. 

Find out what changes have been made and how you now have multiple paths to success with the help of Cisco Certification 2020! The new set of certification exams launched on 24th February. It provides a common language for software developers and networkers to bring the two together. The certification programme will also open-up a brand new horizon of job roles and skill sets that are already starting to emerge. Announced at last year’s Cisco Live event in San Diego, the new DevNet certifications aim to help professionals combine infrastructure expertise with programming to take advantage of the possibilities of intent-based networking. Changes to the Cisco certification programme also include new training and certifications in five key technology tracks. In the traditional Cisco network programme, the certifications range from the associate level to the expert level. The new certification involves a DevNet Associate, a DevNet Professional and soon there will also be a DevNet Expert certification. In this one hour webinar, John Berry discusses what’s new in Cisco Certification, what the professional of the future should look like and how to prepare technology professionals for new roles as a network automation developer.

Find out which OSI layer is concerned with reliable end-to-end delivery of data - and more. Get answers to your OSI reference model and network layer questions here.

ASA and PIX software version 7.0 introduced the configuration command nat-control which didn’t exist in previous versions of code. Although training course material for both the SNAF (Securing Networks with ASA Fundamentals) and SNAA (Securing Networks with ASA Advan...