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Discover the top 5 highest-paying and popular Cisco certifications from the IT Skills and Salary Report. Learn how to get certified and unlock IT career opportunities.

Next Hop Resolution Protocol enables businesses to have a way for next-hop servers and next-hop clients to communicate with each other directly, bypassing a central hub and preventing potential bottlenecks.

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.

Look back at the some of the highest paying IT certifications of 2020.

Every second of every day, data is being sent and received. Billions of data packets are processed by your company’s network every day. In fact, you received dozens of packets just to read this article, but the vast majority of us have no idea how this works. People have no clue as to what goes on behind the scenes to ensure data actually gets to the right device.

Learn about the five types of area networks.

Here are 18 certification options, in no particular order, that are worth your effort based on site searches, feedback from subject matter experts and data in the Global Knowledge 2019 IT Skills and Salary Report.

With Multiprotocol Label Switching (MPLS) as popular as it is in the provider space and private MPLS clouds for larger enterprise, we needed some tools to help troubleshoot and maintain these networks. With the providers in mind, the normal ping or traceroute may not be enough.

The key difference between hubs, switches and bridges is that hubs operate at Layer 1 of the OSI model, while bridges and switches work with MAC addresses at Layer 2 of the OSI model.

Early one morning, an engineer end user discovered that the Engineer servers were unreachable, and he didn’t know if he could reach the Internet. The administrator investigated the user’s PC with the IPCONFIG /ALL command and verified that the PC was a DHCP client, but it had received an address from the Accounting DHCP server, not the Engineering DHCP server.

When you connect your server or storage, it will send a Fabric login (FLOGI) request. This FLOGI request serves two purposes: Fibre Channel ID is the WWPN connection to this port from the FLOGI server Exchange buffer credits with the switch To better understand the first function, it is exactly the same if I rewrite it as, “request an IP address for a MAC address from the DHCP server”.

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.

While cybersecurity remains the most popular certification category in our IT Skills and Salary Report, foundational-level certifications highlight our list of the most popular IT certifications of 2020. 

According to the Global Knowledge IT Skills and Salary Report, women make up 16% of the tech workforce, and an even smaller percentage (8%) are at the senior or executive level. Here’s an overview of the most popular and most pursued certifications by women in tech.

Global Knowledge subject matter experts predict the top trends for 2020 in IT training, Microsoft, Cisco, AWS, cybersecurity and more.

Managers are in dire need of cybersecurity professionals with specific skills. If you’re looking to advance your career, or transfer into the cyber field, now is the time to get certified.

The value of IT certifications has grown considerably over the last decade. Examine the evolution of certification trends, see the top-paying certifications and learn how decision-makers are struggling to hire certified employees.

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. 

In support of software-defined networking, Cisco has introduced several products to strengthen networks and meet the increased demand for flexible and cost-efficient solutions. The Cisco SDN solution in the data center is ACI. Outside the data center the primary Cisco solution is DNA.

The CCNAX - CCNA Routing and Switching Boot Camp is a great option to obtain Cisco Routing and Switching skills while pursuing the CCNA Routing and Switching certification. 

Software-defined networking (SDN) is a solution that will enable your organization to meet the demands of network programmability and automation. The result will be greater network agility to support new applications while complying with increasing security needs.

Global Knowledge subject matter experts know certification exams inside and out. They understand the study methods and test-taking techniques that pay off the most when it’s exam time. Here are 10 certification exam tips and tricks, directly from our experts and Certification Prep Guides, that will best position you for certification success.

How do you measure the experience and knowledge of an IT professional? One way is through certifications. Earning any certification is a notable achievement, though not all certifications carry the same perceived worth.

IT is a very fast changing industry – what is hot today may be a tiny niche market in only a few years and lesser known things may turn out to be huge trends. That having been said, there are many certifications that will be around for a long time. However, this does not imply that recertification and/or continuing education credits are not required to maintain certification. Predicting the future is always challenging, including in IT, but these certifications are good bets.

Routers and switches make up the bulk of network infrastructure and are vulnerable to attack. We hear about mass Denial of Service (DOS) attacks or Distributed Denial of Service (DDOS), but the network itself is as big a risk because if it is taken out, there is no path for the data to flow.

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...

Topping this year’s list is ISACA with four IT certifications, followed by AWS, Cisco and Citrix. Our 2018 IT Skills & Salary Report also shows trending areas in cybersecurity, cloud computing, and business—demonstrating what skills you need to become a more valuable and higher-paid IT professional.

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.

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.

The purpose of Interior Routing Protocols (IGP), and routing protocols more generally, is to advertise the existence of destination networks. All protocols then have some method of picking what they would consider to be the best path and maintain the information. By...

What is Network Time Protocol (NTP)? Well, it’s a network protocol used to synchronize clocks between computing systems over a packet switched network. It’s been around since the mid-1980s and was developed by David Mills at the University of Delaware; it is one of the oldest protocols still around on the Internet. NTP replaced other time synchronization technologies that didn’t have some capabilities to adjust time based on location of the time source or time server relative to the receiver or adjusting to the variation of delay found on typical data networks.

Precision Time Protocol (PTP) is a protocol designed to go beyond what Network Time Protocol (NTP) can offer relative to accuracy. PTP is IEEE standard 1588 that can give local computing systems accuracy within the sub-microsecond range (such as microsecond, nanosecond or picoseconds) whereas NTP is within milliseconds or longer. PTP standard was first released in 2002 and known as 1588-2002. In 2008, the IEEE released a revised standard for PTP, known as 1588-2008, that improved the accuracy and precision of the protocol. It is also known as PTPv2 and is not backward compatible with the older version. PTP was developed for packet based network for control and measurement systems.

One size does not always fit all. At times there’s a need to run more than one routing protocol and have more than one routing domain: multivendor shops, migration from one protocol to another, scalability issues of a single protocol, political or personal preference, production versus test networks, mergers, and acquisitions.

Routers and switches make up the bulk of the network infrastructure and are vulnerable to attack. In a previous article, I talked about some of the different ways of hardening your network devices. In this blog, I’d like to specifically examine the routing protocols used on the major Cisco network operating systems.

Dynamic Multipoint Virtual Private Network (DMVPN) is a Cisco network solution for those with many sites that need access to either a hub site or to each other.

What were the top paying IT and project management certifications for 2016? his article will help you answer both questions by providing a review of the 15 top-paying certifications.

Cisco Internetwork Operating System (IOS) has been around since a little after the inception of Cisco Systems as a company. In 1984, Len and Sandy Bosack from Stanford University founded Cisco Systems with a small commercial gateway server. The first Cisco router that I touched was an Advanced Gateway Server (AGS), which was the first marketed product of the company. After this came the Mid-Range Gateway Server (MGS), the Compact Gateway Server (CGS) and later the Integrated Gateway Server (IGS) and AGS+. The first version of IOS that I touched was 8.2(7). The operating system was based on a Unix-based system and was designed as a monolithic operating system, meaning that processes are stacked and interrelated.

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.

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.

As I’ve stated before, I like Border Gateway Protocol (BGP). I think it’s an interesting protocol, and yes — it’s complicated, but I guess that part of why I like it. There are a lot of knobs to tweak in BGP, maybe too many, but that’s another post. Anyway, we are now running BGP version 4 and it has had extensions written that support more than just IPv4 unicast routing. We now have IPv4 multicast, IPv6 unicast and multicast, VPNv4, VPNv6, and a few others.

Where should you apply the CSS, and why are there two places to apply it? One approach is to pick one of the parameters and apply the permissions there. Quite often, an administrator will pick the phone-level CSS and configure it there so that it applies to all calls made from all lines. The goal is to specify what partitions are allowed to be called. 

For smaller companies, configuring a dial plan to account for variations in dialed numbers is often not a problem. However, companies that are larger and more global in nature encounter a number of issues when designing their dial plan approach.

Border Gateway Protocol (BGP) is a fascinating protocol because there are a lot of things that can be done with BGP. However, there has always been an issue with BGP, which is convergence (the time the network or protocol takes to accept change). BGP was designed for scale, not speed, so it’s something that we’ve had to tolerate from its inception.

License provisioning has always been a bit of a challenge in the CUCM environment. Prior to CUCM v9.0, licensing was managed on a per-cluster basis with each cluster requiring its own license files that were tied to the media access control (MAC) address of the cluster’s publisher. This approach to license management was limiting in the fact that one cluster might have unused licenses while another cluster may be at its limit and sharing between clusters was not possible.

Occasionally I am asked to configure the ability to block calls based on Caller ID. Prior to Cisco Unified Communications Manager (CUCM) v8, the only way to block these calls was to configure voice translation rules and profiles on the gateway receiving the calls. This has changed in CUCM v8 with the introduction of an additional parameter in translation patterns: Route Next Hop By Calling Party Number.

While most organizations have not yet fully (or in many cases even partially) adopted cloud computing, the trend is growing in all but the smallest businesses.

Spanning Tree Protocol (STP) is dead, or at least it should be. It’s too slow to converge when there’s a change, and it causes issues with performance because there is only one forwarding path. It was developed in 1985 by Radia Perlman at Digital Equipment Corporation to allow for redundant paths within a Layer 2 topology, which was great in 1985. In fact, it was huge! So much so, that it was later standardized by the IEEE as 802.1D, and we’ve been living with it ever since.

RTMT provides a set of canned views of both system resources and application counters that provide you with a snapshot of your environment right out of the box. Read on to learn how you can make RTMT even more helpful by customizing it to show you different views of your resources and CUCM environment.

Many companies are already using VoIP while incorporating video capabilities into their portfolio of services. One question that I am often asked is, “How can we ensure that the voice and video quality is good and consistent when using VoIP?”

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.

According to Cisco marketing, Dynamic Multipoint VPN (DMVPN) “will lower capital and operation expenses, simplifies branch communications, reduces deployment complexity, and improves business resiliency.” Okay. But what is it, really, and why should we care?

With the advent of video use in our everyday communications, a number of questions commonly surface. One of them is the question of terminology. What's the difference between video conferencing and telepresence? What is meant by immersive technologies? Frankly, there is no one single right answer.

The short answer (and a common one in our industry): it depends. When comparing Cisco IOS with Juniper Junos, the decision to choose one over the other is difficult and often boils down to cost. Of course, there are other factors to consider.

Frequently, questions come up in the Cisco Contact Center Express classes I teach concerning the ability of the system to perform this or that task. In this blog post, I will cover some of the more popular questions I get during class.

This is another topic of heated debate, and it changes from network to network, but I found a simple approach that works in most cases. Since I have four queues and four classes of traffic, I need to categorize my important traffic into four classes. Strictly for explanation purposes I took some liberty in defining four categories of traffic that are very effective in both large and small networks. These classes are: Real Time Protocol (RTP), Network Management (NetMgt), Business Critical, and the Default.

Regardless of your vendor preference or your experience on the Juniper JUNOS CLI, assuming you have a point of reference to another vendor, your first thought when experiencing JUNOS is, “I have been here before.” The CLI is familiar, convenient, and polished. The similarities between JUNOS CLI and another CLI such as Cisco’s IOS are not what I want to focus on here however; it is their differences I want to focus on. But first, when you connect to a JUNOS powered device and access Operational Mode (see Brad Wilson’s blog post Introduction to Juniper Junos), it looks very much like the User EXEC Mode in IOS. In fact, there are a lot of JUNOS commands that are very much like the IOS User EXEC Mode commands.

That depends on their configurations. For example: While it makes very good sense to include redundant physical links in a network, connecting switches in loops, without taking the appropriate measures, will cause havoc on a network. Without the correct measures, a switch floods broadcast frames out all of its ports, causing serious problems for the network devices. The main problem is a broadcast storm where broadcast frames are flooded through every switch until all available bandwidth is used and all network devices have more inbound frames than they can process.

As we discussed previously, Cisco created the Nexus Operating System (NX-OS) to power its next-generation data-center switching platform. While this new OS shares many similarities to the original IOS, there are some definite differences that you need to be aware of as you begin using it.

The most obvious difference is that hubs operate at Layer 1 of the OSI model while bridges and switches work with MAC addresses at Layer 2 of the OSI model. Hubs are really just multi-port repeaters. They ignore the content of an Ethernet frame and simply resend every frame they receive out every interface on the hub. The challenge is that the Ethernet frames will show up at every device attached to a hub instead of just the intended destination (a security gap), and inbound frames often collide with outbound frames (a performance issue).

This week we'll review the IPv4 Address Classes including subnet masks, examples of Class C, Class B, and Class A subnet masks, and planning IPv4 addresses.

Both technologies, Ethernet and FC, satisfied the two conditions at that time, but there was a catch. Read more. 

None of us have much time to waste, so what can you do when your environment changes quickly and you need to come up to speed on a device that you have never seen before? You find the quickest way to bring yourself up to speed. Some of you will have experience with other vendors’ equipment, and some of you will not have much experience at all; therefore, we will focus on topics that will get your feet wet the quickest and have you talking Junos in no time.

In the previous post, we discussed the need for VXLAN in the cloud along with the issues it solves. In this post, we will focus more on how VXLAN works.

Configuring a wireless lab for study and testing capabilities is a bit more involved than you might think at first glance. Most of the requirements take place on the management devices, but the underlying switch infrastructure requires some preparations as well. The tasks involved are as follows:

Anyone who’s managed switches over the years knows that the Spanning-tree protocol (STP) is both the best and worst thing to ever happen to the data center at layer 2 of the OSI model. On the plus side, the Spanning-tree protocol is what first allowed us to create redundant paths within our switching infrastructure, making our data center much more resilient to outages than ever before. Anyone who’s experienced a “broadcast storm” knows the full value of Spanning-tree in the traditional switching environment. We’ve also seen many improvements in Spanning-tree over the years to make it work faster and more efficiently (i.e. Rapid Spanning-tree, Bridge Assurance, and many others).

Previously, I talked about the logical and physical steps to building a basic certification lab, concentrating mostly on the CCENT/CCNA Routing and Switching level. Once you have that set of certifications under your belt, there are several options for specialization. Each of these advanced technology tracks serve as methods of enhancing your professional skill set as follows:

The Cisco UCS is truly a “unified” architecture that integrates three major datacenter technologies into a single, coherent system: Computing Network Storage Instead of being simply the next generation of blade servers, the Cisco UCS is an innova­tive architecture designed from scratch to be highly scalable, efficient, and powerful with one-third less infrastructure than traditional blade servers.

The official Cisco CCNP Security FIREWALL training course (as well as other documentation) recommends enabling the inspection of the Internet Control Message Protocol (ICMP), even though it’s disabled by default. The image below displays the recommended practice as configured in ASDM, but the curious student might wonder what the unchecked “ICMP Error” box is. That’s what I’ll focus on in this post.

In this post I’ll focus on a topic that’s mentioned in the Cisco FIREWALL training class but isn’t emphasized there or in the online Cisco ASA documentation. When configuring failover on a pair of ASA security appliances, a situation can arise in which network disruption occurs due to the secondary ASA in a failover pair becoming active first and then the primary comes online second. Both the documentation and the courseware point out that this causes the secondary (and active ASA) to swap its interface MAC addresses with those of the primary. Being naturally skeptical about this behavior, I decided to investigate. The rest of this post illustrates my confirmation of this phenomenon.

Although the GSS can be configured to be authoritative for an entire domain, e.g. cisco.com (option 1), the GSS is designed to be integrated into an existing traditional BIND-based or any DNS system. The GSS operates as an A-record DNS server for Hosted Domains (HD) for which it has been delegated authority from a higher-level name server, which generally would be a name server (NS) controlled by an Enterprise or ISP. In addition to A-record support, the GSS is able to proxy for other query types using NS Forwarding and a back-end name server such as BIND.

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.

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.

This week’s post highlights some of the features and implementation specifics regarding the Datagram Transport Layer Service (DTLS) protocol used in Virtual Private Networks with the Cisco AnyConnect^® SSL client. I’ll provide some background as well as some screenshots and supported CLI commands.

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.

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.

When the hostname.domainname associated with my Small Office Home Office (SOHO) failed to update after a power outage, and a new DHCP-assigned external address was assigned to my router, I was reminded of the need for Dynamic DNS. This article will explore the implem...

As is frequently the case these days, I get a brainstorm for an article during a Cisco Security training class I conduct. This summer I taught the Securing Networks with ASA Fundamentals class, which concentrates heavily on the Adaptive Security Device Manager (ASDM)...

As is sometimes the case, the idea for this article originated with a student question I received during one of the Securing Networks with ASA Fundamentals classes I have taught this summer. The course material mentions a simple scenario whereby IP Telephony traffic...

I recently came across an opportunity to use a relatively new feature in Cisco Unified Communications Manager (CUCM). Suppose you are the telecom administrator at a community hospital. During business hours, the Facilities Department is staffed and team members simpl...