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There are several Wireless LAN Standards, including b, g, and n, which exist in the 2.4 GHz band. These standards need around 20 MHz of radio frequency in order to transmit their signals. In this video, Ben Miller discusses how to pick access points and channels for optimal performance.
Are you at a crossroads professionally or looking to start training for a new job? If so, you might want to consider pursuing network administration as a career. Network administrators are responsible for maintaining computer hardware and software systems that make up a computer network, including maintaining and monitoring active data networks, converged infrastructure networks, and related network equipment.
I recently responded to a message on LinkedIn from a regular reader of this blog. He asked several questions which I will answer over the course of several posts. As part of his first question, he described a strategy report that his group is producing. The audience for this strategy report considers ITIL important to the future of their business, and so he must describe which ITIL processes his data center operations group works most closely with.
The technologies examined reduce operational expenses (OpEx), not capital expenses (CapEx) that has traditionally been the focus of virtualization. Many companies implemented virtualization with the goal of saving money in the form of fewer servers to buy with a side benefit of reducing the footprint of the servers and lowering the required power and cooling. Most of the savings were in capital, but do not expect the same with many of the technologies listed here, because some may even require some additional capital expenditures, at least for software, in order to save on the day-to-day operations of IT. The bigger cost in running an IT department is in the OpEx category anyway, so savings there are recurring.
Answer? When it is flagged as a retransmission in Wireshark!
vSphere 5.5 is now available with myriad small improvements such as a faster Web Client, LACP, Autoscale and higher configuration maximums. In addition, there are changes coming such as VSAN, which may be ground-breaking in regard to VM storage of the future. Since the release of vSphere 5.5, they have not yet announced a change to the blueprint for the test. That being the case, I will say, for now, that the VCP-510 test should remain unchanged as well. My goal here is not to reeducate you on everything that you need to know for the test; instead, it is to point out the few changes that might apply in your company or organization.
CompTIA has raised the bar for Network+ candidates. The new certification exam has significant changes to the five "domains" or knowledge areas with new content related to security, cloud, data-center and operational concerns and troubleshooting. There is also a greater emphasis on wireless networking and VoIP. Use this white paper to help you gain an overview of what's new and what's different.
Good question! There are lots of networks, so I’m sorry to say that it depends. Let me explain. The smallest computer-based networks are usually PANs or Personal Area Networks. They can connect a wireless keyboard, mouse, or other devices to a computer. You may find them wirelessly linking a printer to your computer. You may have noticed these all include wireless connections. A PAN most often uses wireless technologies like infrared and Bluetooth, so it is really a WPAN (Wireless Personal Area Network).
“Twisted Pair” is another way to identify a network cabling solution that’s also called Unshielded Twisted Pair (UTP) and was invented by Alexander Graham Bell in 1881. Indoor business telephone applications use them in 25-pair bundles. In homes, they were down to four wires, but in networking we use them in 8-wire cables. By twisting the pairs at different rates (twists per foot), cable manufacturers can reduce the electromagnetic pulses coming from the cable while improving the cable’s ability to reject common electronic noise from the environment.
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).
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.
Multiplexing is the technology that is able to combine multiple communication signals together in order for them to traverse an otherwise single signal communication medium simultaneously. Multiplexing can be applied to both analog and digital signals. A benefit of using multiplexing, or muxing, is reducing the physical hardware cost for expensive dedicated network communication segments, such as copper or fiber cables.
Learn about the five types of area networks.
Now that the network is installed, each switch has a bridge ID number, and the root switch has been elected, the next step is for each switch to perform a calculation to determine the best link to the root switch. Each switch will do this by comparing the path cost for each link based on the speed. For paths that go through one or more other switches, the link costs are added. The switch compares this aggregate value to the other link costs to determine the best path to the root switch.
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.
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.
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.
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.
One of the most important steps in mastering a new technology is learning the associated terminology or vocabulary. In the IT field, this can be a very challenging step, as much of the terminology is often used inconsistently. This white paper defines the terminology associated with IT virtualization. It is mainly vendor-agnostic, but it does provide some vendor-specific terms, product names, and feature names used by VMware, Citrix, and Microsoft.
In 2013, VMware announced VMware Virtual SAN (VSAN), which is VMware's native version of Software Defined Storage (SDS). It is simple, easy to setup and managed by user-defined policies. This paper explains VSAN, its basic requirements and how it works.
Resource Pools are often misunderstood, disliked, and untrusted by vSphere Administrators. However, resource pools can be very useful tools for administrators who want to configure resource management without having to individually configure each VM. This leads to the administrator’s desire to explore the proper usage of resource pools.
This vSphere Essentials white paper will give you a basic understanding of some of the concerns or planning points to consider as you get ready to deploy vSphere in your organization. This is a glimpse into some of the essential things to consider for implementing vSphere. This will focus on some of the basics that vSphere administrators run into when installing the latest features and not realizing they still have some older versions implemented.
When properly utilized, VLANs and trunks provide flexibility, stability and ease of troubleshooting. This paper provides technical details about VLANs and trunks, along with design options at a basic to intermediate level. Recommendations and commands are included throughout.
While the recent trend towards cloud computing might make it seem like virtualization is new, it has existed in some form for many decades.
Examine fifteen common myths surrounding virtualization, including many that prevent IT administrators (or their bosses) from getting the maximum value from virtualization. This paper is designed to be vendor-neutral; in other words, the basic concepts and advantages are the same whether you choose to use Citrix XenServer, VMware vSphere, Microsoft Hyper-V, or one of the many Linux-based solutions. We'll break the reasons into three broad categories (Cost/ROI, Performance, and Other), allowing you to focus in on a specific area if desired, or you can review the entire white paper for a broader view.
This article defines many of the most commonly used terms in the virtualization vocabulary.
Virtualization is an umbrella term that continues to evolve to include many different types that are used in many different ways in production environments. Originally virtualization was done by writing software and firmware code for physical equipment so that the physical equipment could run multiple jobs at once. With the success of VMware and its virtualization of x86 hardware, the term virtualization has grown to include not just virtualizing servers, but whole new areas of IT. This article is going to look at the origins of virtualization and how some of the historical development has spurred on today's virtualization. In addition, we will discuss different types of virtualization that are being utilized in the marketplace today and a listing of some of the leading vendors.
Many people believe that cloud computing requires server (or desktop) virtualization. But does it? We will look at using virtualization without cloud computing, cloud computing without virtualization, and then look at using both together. In each case, we'll look at where each deployment might be most useful, some use cases for it and some limitations.
One of the many useful features of tunneling is to carry non-IP traffic across an IP network, and this is still the case when dealing with IPv6 traffic. This transition mechanism makes use of a configured tunnel to transport IPv6 over a native IPv4 network, which may consist of two sites or more. Unlike the previous transition mechanisms, tunneling is not monolithic; while the basic principles may be similar, the operations are different. The following chart gives a breakdown of the current, major tunneling types in use, particularly in a Cisco environment:
If you are upgrading to ESXi 5.1, there are some important facts that you should consider first. Upgrading involves many stages and processes that must be performed in a specific order. Many of these processes are one-way and do not provide a "back button." If you do not use care and consideration in your upgrade plan, you could possibly lose important data and configuration; and potentially even lose contact with your servers.
There is a wide-range of services available in GCP ranging from Infrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS) to completely managed Software-as-a-Service (SaaS). In the first part of this series, we will discuss the available infrastructure components and how they provide a powerful and flexible foundation on which to build your applications.
Global Knowledge Product Manager Tori Easterly discusses the benefits of our Understanding Networking Fundamentals course.
Explore how IT decision-makers’ training views have changed since we first released our annual IT Skills and Salary Report 12 years ago. Once viewed as an expense, IT leadership now sees professional development as an investment. Even with shrinking budgets and a recent rise in skills gaps, the value of training is currently at an all-time high.
VMware announced Horizon 7 in February and subsequently released the software updates. Horizon 7 provides a more streamlined, high-performance virtual desktop and application experience. New updates include features such as Instant Clones, Smart Policies, Blast Extreme and greater scalability with Cloud Pod Architecture. Let’s dig into the seven key features that Horizon 7 brings!
Global Knowledge subject matter experts predict the top trends for 2020 in IT training, Microsoft, Cisco, AWS, cybersecurity and more.
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.
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.
When we learn a concept for the first time, the newness of it tends to become embedded with the learning process. We remember the new idea's significance and forever after remember it as new. The initial impact of a discovery can prevent the concept from aging. At the same time, we realize how quickly technology advances. Is it time to evolve your expertise?
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.
This short example illustrates basic VLAN operation. Examining VLANs in a large-scale installation can show the full benefits of VLANs. Consider that this is a small portion of a large corporate headquarters with 5,000 devices connected in a 20 building campus.
In the digital age, people and intellectual property have supplanted physical assets as the most important criteria for determining the value of an organization. It is the employees who develop the next big product or improve the practices, processes, services and internal culture that add significant value to an organization.
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.
Session Initiation Protocol (SIP) is an internet signaling protocol, developed by the IETF (starting in 1996), for establishing, maintaining, and tearing down sessions between a variety of real-time media, including voice, video, and chat. SIP allows endpoints to locate other endpoints, whether stationary or mobile. SIP doesn't have to worry about transporting voice or video as Real Time Transport Protocol (RTP) takes care of that. It also relies on Session Description Protocol (SDP) to negotiate capabilities and codecs. SIP does not provide a Directory Service or Authentication, but it does work with services such as LDAP or RADIUS. SIP is only concerned with signaling. This white paper is going to look at the way SIP is used in the converged Unified Communications environment.
This white paper has three main goals. The first is to generate a better understanding of the cloud in both the business and IT communities. The second is to describe the major components of vCloud and the virtual datacenters they provide. The third is help businesses visualize and understand how vClouds could be beneficial in addressing their specific IT needs.
VMware vCloud Director fashions the provisioning of the software-defined datacenter layer to allow for a full virtual datacenter deployment within a short period of time. A vCloud consists of many layers and can quickly become a complex architecture. Before any deployment, requirements should be defined so that the vCloud can be designed to offer those services needed. It is imperative to understand the many components of vCloud, how each vCloud construct fits, which allocation models are available, and what network options can be chosen.
In a recent post, I gave an overall description of a service portfolio and the key components of a portfolio. Here, I will describe how a cloud services provider might implement an ITIL service portfolio. A cloud services provider will regularly have a set of services under development, a set of service in live operation, and a set of services that are retired.
After a review of Software-Defined Networking (SDN) and its close cousin Network Functions Virtualization (NFV), this white paper addresses three main deployment scenarios: SDN without deploying cloud computing, cloud computing without deploying SDN, and deploying cloud computing in conjunction with SDN. We'll look at use cases, when the approach makes sense, and any applicable limitations.
The STP (Spanning Tree Protocol) standard (IEEE 802.1d) was designed when the recovery after an outage could wait a minute or so and be acceptable performance. With Layer 3 switching in LANs, switching began to compete with routers running protocols because they are able to offer faster alternate paths. Rapid Spanning Tree Protocol (RSTP or IEEE 802.1w) brought the ability to take the twenty seconds of waiting for the Max Age counter plus fifteen seconds of Listening plus fifteen seconds of Learning or fifty seconds down to less than one second for point-to-point connected and edge switches and six seconds for root switches.
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.
The utility that many senior VMware administrators rely on to address performance and troubleshooting issues is the built-in utility called ESXTOP. The tool has been built in to the hypervisor, and can be used in both ESXi and the old ESX host. The first tool many VMware Administrators rely upon is esxtop, to check real-time performance on an ESXi host using a command-line tool such as ssh to start the esxtop CLI utility. This paper will introduce and demonstrate how to start and use esxtop, specifically looking at the CPU fields. In addition, we will cover information that can be used to help with performance issues of the CPU. The esxtop utility is an excellent tool to use when you want to observe an individual ESXi host's performance.
Using Palo Alto Networks, PAN-OS, enterprises can build an IT Security Platform capable of delivering protection against all stages of the Cyber-Attack Lifecycle. From Reconnaissance to Act on Objective, the PAN-OS Single-Pass Parallel Processing (SP3) engine combines efficient throughput with maximum data protection. This recorded webinar will describe how the SP3 Architecture can increase network traffic visibility and enable you to control your environment.
Most Internet users don't realize that often a website or other service that seems slow to respond is actually working fine. Instead, it’s the resolution of DNS that is putting a glitch in your giddy up. Fortunately, there are several steps you can take to optimize your DNS to get better performance.
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 this hour-long webinar, security expert and Global Knowledge instructor Phillip D. Shade will provide insight into the emerging network security science of network forensics analysis, a.k.a. security event analysis and reconstruction. Using case studies, you will examine the role of data retention in network forensics analysis, and you will learn about applying forensics analysis techniques to handle application-based attacks, VoIP call interception, and worms, bots, and viruses.
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.
The Logical Volume Manager (LVM) is a powerful tool for managing storage on Linux servers. This video provides an overview of how LVM works and explores several ways that LVM makes storage management easier and more flexible. Examples include how to expand storage capacity on the fly using LVM and resize2fs, and how to migrate data from local storage to a storage area network (SAN) without downtime using pvmove.
In this paper, we explore the basic usage of PowerShell in the pursuit of automating the management of Hyper-V deployments. This paper is targeted to IT professionals who have been "GUI-bound" to their management interfaces and have been working with or are embarking on the journey of Hyper-V administration. We'll explore the usage of Hyper-V specific cmdlets with the intent of ultimately being able to include multiple cmdlets in a "script" to allow for pushing one button and accomplishing the combined actions of many multiple mouse clicks in the GUI. No more repetitive tasks!
Organizations are moving strongly toward Bring Your Own Device (BYOD) access, bringing outsourced activities back in-house, and finding ways to make use of the growing amounts of data flowing in from many new sources such as social media. These factors create an increasing shift in required and desired skills showing up in IT departments. Hiring and salary surveys, such as the 2014 IT Skills and Salary Survey from Global Knowledge and Windows IP Pro, TEKsystems' 2014 Annual IT Forecast, Foote Research Group's 2014 IT Skills and Certifications Pay Index, Computerworld's annual Forecast survey, Robert Half Technology Survey, and information from the US Bureau of Labor Statistics, Futurestep, Mondo, GovLoop, and Dice have presented a developing picture of the IT skills that will be in demand in 2014. Here, in survey order, are the top 10 major skills and why they made the list.
An quick fundamental overview of layer two devices. To learn more about this and similar topics, enroll in our exclusive Understanding Networking Fundamentals course.
Network Functions Virtualization (NFV) is gaining momentum along with Software-Defined Networking (SDN). This paper examines the history of NFV and explores the prospects for networking to gradually evolve from a hardware-centric approach to a software-driven model. It concludes with an examination of future market implications and how NFV can help organizations to achieve their goals.
The first big push toward implementation of IPv6 was mobile devices. Now, one of the driving forces is the Internet of Things. As the name implies, this means everything, including machine to machine communication (M2M).
As with the adoption of any new technology, the move from IP version 4 to IP version 6 will take a number of years to complete. During that transition phase, various mechanisms will be necessary to continue support of the older protocol as the newer gains widespread momentum. In addition, there has been some evolution even within the availability of these mechanisms, some of which have already passed from general use into deprecated status. Network engineering professionals already proficient in the use of IPv6, as well as the available coexistence mechanisms, will undoubtedly stay in high demand throughout this process.
In 1998, the Internet Engineering Task Force (IETF) released RFC 2460, outlining the technical specifications of IPv6, which addressed the shortcomings of the aging IPv4 protocol. As with any evolution of technology, new elements exist in the protocol that may seem strange and unfamiliar. This certainly includes address representation, space, and so forth, but also includes a number of different types of addresses as well. A subset of these new addressing types has corresponding types in IPv4, but many will seem significantly different. The purpose of this white paper is to examine addressing classifications in detail and outline their functions within the context of the protocol.
One of the most significant new features in Microsoft Windows Server 2012 is the Hyper-V Replica (HVR) capability. Whether you are considering this for your own organization or just prepping for your Windows Server 2012 MCSA, this white paper presents the essentials of deploying this disaster recovery feature.
Take your VMware vSphere training to the next level—set up your own training lab environment. This paper is broken down into three major sections: the hardware required, the VMware Workstation configuration, and installing vSphere and vCenter (vC).
The driver behind 802.11n is MIMO, or multiple input multiple output. This video explains how MIMO works to double your channel speed by sending two or more data streams over the same channel.
The OSI model is a conceptual tool used to discuss and describe network functions. The use of a standard reference model is essential to communicate ideas as well as create new technologies. It is a good idea to be familiar with the OSI model, the features assigned to each layer, and examples of common protocols or technologies associated with the OSI layers.
A local area network (LAN) provides a path of communication, allowing the delivery of packets of data, voice, or video originating from the sender (logical source address) to the receiver (logical destination address). Ethernet is the most common LAN used. As you start to learn about networking, remember that communication and the movement of large numbers, whether it is people, cars, mail, or network traffic, have a commonality. Everything you know and use in your daily life can be compared to the way traffic moves.
Wi-Fi networks have been misunderstood by much of the IT community since their inception. Even the reasons for this misunderstanding are kind of hard to understand. The result has been that myths about 802.11 (better known as Wi-Fi) networks have grown almost as fast as the technology itself. In this web seminar, we'll examine 11 common Wi-Fi myths and explore ways to use correct information to make your networks scalable, secure and satisfying for your users.
While Apple has created many fine things, they were yet to be created themselves when Xerox PARC scientists created Media Access Control addresses. These MAC addresses are 48 bits or 6 bytes long, so they are also known as MAC-48 or EUI-48. EUI stands for Extended Unique Identifier. It is written in hexadecimal characters as shown below:
For us wireless folks that aren’t stellar routing and switching guys, one of the most daunting network tasks is integrating our WLAN infrastructure with the existing wired infrastructure and its services. Understanding wired design topics is pretty fundamental to installing or managing any network, so it really should be on our priority list to spruce up those skills. To give you a nudge on your journey, let’s talk about DHCP for wireless clients.
Depending on the switch vendor, the exact steps will vary on how to set up and configure VLANs on a switch. For the network design shown, the general process for setting up VLANs on the switch is:
This paper covers the configuration of IP Multicast with Multiprotocol Label Switching (MPLS) including the basics of Multicast with the Group Encrypted Transport VPN (GETVPN).
Often, we don't have time to learn the reasons behind the standards we use. But learning what instigated a standard goes a long way toward not only understanding its importance, but also more easily and effectively applying it in your workplace. In this hour-long webinar, Global Knowledge instructor Keith Sorn will discuss common networking standards and explain how they were determined and why they are relevant. He will fill you in on things like why it's important to use proper color-coding standards when making cable and why the length limitations on wired cable are essential. He will also explain new standards, such as power over fiber.
The traditional network engineering model of configuring one device at a time simply doesn’t scale to the growing needs of today’s network. Cisco's intent-based networks and software-defined networking solutions 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.
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.