Resource Library

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.

The triple constraints model has been one of the main staples for teaching project management for as long as I can remember. The model is generally represented by a triangle with Scope on the horizontal leg, Time on the left leg, Cost or Resources on the right leg an...

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,...

If you create presentations using the notes feature in PowerPoint, you probably have found yourself wanting to print multiple slides on one page (handouts) with the notes associated with those slides displayed on the same page. This layout can often help you better p...

When integrating a Voice over IP (VoIP) system into an existing network it is very important to have a good understanding of how much bandwidth is utilized for each call on the network. For most people, just starting out the bandwidth calculations can be a very daunt...

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...

Recently we've been comparing using Telnet with Secure Shell protocol to allow remote access to a device such as a router or switch. Now, we're going to compare File Transfer Protocol (FTP) and Trivial File Transfer protocol (TFTP) for a Cisco router or switch. These...

RIP is a protocol that is used for routing IP networks. It was designed in the early 1980’s for communication between gateways (computers with two NIC’s). It is the oldest routing protocol used by the network industry and is considered by many to be inefficient or bo...

So far, in our discussion of Router Information Protocol (RIP), we’ve discussed the basics and also verified and reviewed RIP version1. We stated that RIP version 1 is a classful routing protocol that used FLSM and sent it routing updates without the subnet mask.  In...

Devices must send dual-tone-multi-frequency (DTMF) when a phone call is routed to an automated system. Automated attendant (AA), voicemail (VM), or interactive voice response (IVR) systems are some examples of the types of automated systems that can pick up phone calls.

Exchange 2010 builds upon the significant changes to the transport that were made in Exchange 2007. In this article, I'll review the transport pipeline and routing components and list some of the new architectural and administrative enhancements to the Exchange 2010...

Call Admission Control (CAC) is often times included as part of the same topic as Quality of Service (QoS), when in actuality CAC is a separate and complete topic itself. QoS is defined as traffic engineering on a packet switched network. This definition means movin...

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.

When sending data end-to-end through a network, routers are used in internetworking to create a virtual network from one device to another, either locally or globally. Routers are configured to operate with most common network protocols. That means they know the form...

Cisco Unified Communications Manager (CUCM) includes a feature called "call throttling" that denies new call attempts when the system is in a state that may lead to delayed dial tone. The Real Time Monitoring Tool (RTMT) will generate a code yellow alert when call t...

No matter what book or manual you use to study for the CCNA examination, you will see various protocols and processes referencing an RFC. And, although frequently referenced, the RFCs are seldom actually included in the documentation. So, the logical question becomes...

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...

Cisco IP phones support a variety of different audio codecs. In this post, I will explain some of the differences and explain which versions of CUCM and the Cisco IP phones support the various audio codecs. Audio codecs are responsible for sampling human speech (a s...

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...

There are some common misconceptions on the part of some of my students as to how VPN sessions are established from either a remote location or remote user to the ASA firewall. In particular, a “gray area” seems to be when the attributes from the tunnel group are app...

One aspect of Unified Communications is this concept of trunk groups.  I will discuss what they are, what benefit they can provide and how to configure them for Cisco gateways. First of all the official definition of a trunk group is “A group of trunks serving the s...

Last blog we looked at how we can use Trunk groups to ease the configuration of dial-peers and digit manipulation using analog FXO ports for an E911 solution. Now let’s take a look on how it can be used for T-1 CAS configurations and ISDN channel selection. The firs...

Project procurement activities are often managed by specialists. By this I mean that the procurement department takes over responsibility for purchasing and contract management from the project manager. As a result of this separation of responsibilities, the steps and stages of procurement are often poorly understood by PMs. In this and the next few blog submissions, I will attempt to shed light on procurement activities and relate these activities to the PMI PMBOK.

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...

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...

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.

I recently was presented with the challenge of logging ALL of the pertinent connection, disconnection, and termination messages associated with the Cisco SSL AnyConnect client without overwhelming the syslog capture display with extraneous messages. This blog will br...

Microsoft SQL Server has evolved over the years as a scalable, robust database management system and is now competing in the VLDB (Very Large Database) space with Oracle and IBM. The market share for the product continues to grow, based on total cost of ownership and ease of use. This white paper outlines some of the important fundamentals of Microsoft SQL Server 2008 that every DBA should know.

The definition of cloud computing depends largely on whether you are a consumer or producer. The public cloud is geared more for the individual consumer or small company, while the private cloud is geared more for a medium-to-large company. In addition, the private cloud is branching out to incorporate the ability to have some data and applications serviced from the public cloud. This white paper examines the different types of cloud computing and shows what cloud computing can offer you.

The flexibility, reduced cost, and mobility of cloud computing have made the concept a hot topic. Before implementing this method of computing, however, it is important to consider the security of the "cloud." In this white paper, you will learn some of the risks and benefits of cloud computing to be sure it is the right solution for you.

Recently, I was asked the following question: “We plan to implement Windows 7 in our network very soon. We want to use Windows 2003 Domain Controllers for the next couple of years. Can we make the hundreds of new Group Policy setting available to Windows 7 Windows Server 2003 DCs?” This is not an unusual situation. Some organizations find they need to replace their desktop computers immediately because of age or obsolescence and others wish to upgrade to Windows 7 because of its superior security and performance. But there may be no budget or desire to upgrade to Windows 2008 or 2008 R2. Luckily, it is not difficult to adapt Server 2003 to work with Windows 7.

In my last post, we learned that the Dynamic Host Configuration Protocol (DHCP) is a computer networking protocol used by hosts, identified as DHCP clients, to retrieve IP address assignments and other configuration information. DHCP uses a client-server architectur...

There are many interesting new issues that seem to have come with the addition of voice and video to the data network. Most of the engineers that are now working on VoIP networks come from either a pure data network background or a traditional phone system background...

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!

Windows 7 can be a good file server on very small workgroup networks. Although Windows 7 is limited to only 10 concurrent client connections as a file server it can do a good job making files accessible over a network. Windows 7 shares a great deal of code with Windo...

The flexibility, reduced cost, and mobility of cloud computing have made the concept a hot topic. Before implementing this method of computing, however, it is important to consider the security of the "cloud." During this webinar, we will help you understand some of the risks and benefits of cloud computing so you can decide if it is the right solution for you.

Even in professionally managed network environments it is still possible for mistakes to happen. If an Active Directory object such as a user or computer account is accidentally deleted  network access will be lost. Worker productivity will decline until the account...

The subject of this week’s post was actually prompted by a question from a former colleague.  Soon after the PIX Firewall added support for IPSec Virtual Private Networks, a command was added to the command-line, sysopt connection permit-ipsec. This command was subse...

Private networks are under constant threat of attack, even when steps have been taken to "secure" them. The large volume of malicious codes, and their ability to evolve and adapt, requires security professionals and common computer/internet users alike to be mindful of their actions and constantly play defense. This white paper focuses on 10 common ways that malicious code can penetrate a network. Knowledge of these methods and the ability to recognize them are the first steps in preventing them from succeeding in harming your network.

Windows Vista introduced AERO, a desktop experience that had four major elements; Windows Flip, Windows Filmstrip, AERO Glass transparency and fully realized thumbnail views on the Taskbar. Windows 7 added several new features to AERO, including AERO Snap, AERO Shake...

Occasionally as I'm teaching a Cisco training class, I get an idea for a blog post and it happened again this week. The Securing Networks with ASA Fundamentals curriculum is mostly based on the Adaptive Security Device Manager (ASDM). While the class describes the us...

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...

Windows Software Update Services (WSUS) is commonly used to distribute security patches and updates for Windows operating systems and Microsoft applications. WSUS is a web application that runs within Internet Information Services (IIS) on Windows Server. When client...

Adding a new computer to an Active Directory domain can be a disruptive process, particularly if that computer is part of a large, high-speed deployment. Djoin.exe is a command line tool that permits the joining of a Windows 7 or Server 2008 R2 computer to Active Dir...

A feature common to IPSec Virtual Private Network implementations throughout the Cisco product line is Perfect Forward Secrecy (PFS). This optional additional component is now a default supplied configuration setting with the Adaptive Security Device Manager (ASDM) I...

As any network administrator will tell you, the ASA Security appliance (as well as its forerunner, the PIX) are capable of generating massive amounts of log messages, especially when the firewall/security appliance is set to log messages at debug level to the syslog...

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...

No matter which IT field you're working in, there are several skills that are useful for every IT professional to know. Here, seven experienced IT professionals working in the networking, programming, project management, and security fields, share what they believe a...

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)...

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...

Organizations can find significant value in adopting Agile methodologies and techniques. Agile practices can help ensure meet customer expectations, deliver products on time, and create a motivated environment that is able to quickly adapt to change. This white paper explores 12 benefits of Agile development and management, explaining why you should consider incorporating Agile methodologies into your current standards and processes.

Need to know the difference between copper and optical fiber? Want to learn what the acronyms PBX, PC, PCI, PCIe, PCM, PDA, and PDU mean? Our "Geek Speak v3.0" can teach you all this and more. An update to our popular v2.0 "Geek Speak", this white paper will teach you more than 925 popular IT words, phrases, and acronyms.

Negotiation is a dialogue intended to resolve disputes, to produce an agreement on courses of action, to bargain for individual or collective advantage, or to craft outcomes to satisfy various interests. It is the primary method of alternative dispute resolution. This white paper focuses primarily on the negotiation process, different negotiation styles, and the various elements of communication that affect the outcome, including: Negotiation Communications, Constructive Questioning, Communication Obstacles (and overcoming those obstacles), Challenging Negotiation Situations and "Traps," and, finally, completing Successful Negotiations, a.k.a. "Getting to Yes"

In this webinar, the first of two based on our Cybersecurity Foundations course, you will examine the following topics: verifying users and what they can access, ways a user can be validated to computer and network resources, how cryptography is used to protect data, symmetric and asymmetric encryption and hashes.

Dcdiag is an often overlooked tool that can discover problems in a domain controller’s configuration. If client computers can't locate a domain controller or if domain controllers can't replicate Active Directory, you can run tests with Dcdiag to look for a solution.

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 this webinar, the second of two based on our Cybersecurity Foundations course, you'll build on what you learned in the first of the series, Protecting Your Network with Authentication and Cryptography.

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.

In this webinar, you will examine the need for IPv6 and whether it's possible to survive on IPv6 alone. You will learn ways to phase in IPv6 and how to successfully migrate to IPv6.

I attended a meeting this week with a customer of mine and a potential new vendor. The new vendor was there to pitch his configuration and setup service offerings for a specific ITSM toolset. My customer has already had one bad experience with an ITSM tool configuration vendor who promised one thing and delivered much less. He ended up with a tool that’s minimally used and not configured to match his business needs. He’s looking for a vendor that can understand his business needs and priorities and quickly help him get his tool configured and working in a short time frame. Then the topic of standard changes came up. My customer asked for examples of standard changes. The vendor responded, “Server reboots are an example of standard changes.”

Planning for a cyber disaster makes recovering from one much easier. Still, as important as disaster planning is, it's often overlooked or put off until it is too late. In this webinar, Global Knowledge instructor Debbie Dahlin discusses planning for the unexpected -- whether the unexpected means a simple power outage, a network security breach, or a major natural disaster. She'll discuss risk analysis and risk management techniques and explain the importance and process of creating a business continuity plan. Using a fictional company as an example, Debbie will walk you through the disaster planning process a security professional should use, and she will provide simple tricks to reduce your company's downtime before, during, and after a disaster.

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.

In the fourth of his five-part series, Eric Strause explores the hardware and application benefits inherent in a cloud-based architecture.

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.

Global Knowledge Course Director and Lab Topology Architect Joey DeWiele, a specialist in Unified Communications, explains the difference between our Cisco Unified Communications courses - ACUCW1 & ACUCW2.

In this informative, hour-long webinar, Global Knowledge instructor Debbie Dahlin will explore an abundance of important cloud computing security issues. She will help you gain insight into the key cloud security issues of maintaining the confidentiality, integrity, and availability of corporate information and applications.

An attacker needs to destroy evidence of his presence and activities for several reasons like being able to maintain access and evade detection (and the resulting punishment). Erasing evidence of a compromise is a requirement for any attacker who wants to remain obscure and evade trace back. This usually starts with erasing the contaminated logins and any possible error messages that may have been generated from the attack process.

Relational databases are important not only because of the information they store but, more importantly, for the data we retrieve from them. The select statement allows us to ask the database a question. It’s the way we retrieve information from the database system.

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 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.

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.

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.

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.

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.

This report discusses the growing significance of human capital and intellectual property on the performance, sustainability, and valuation of companies. It examines the business drivers for investing in the acquisition, development, and certification of knowledge workers as well as current technology and economic trends that are accentuating the critical need to invest in the education and training of employees and customers.

As long as I've been involved in service management, one of the perennial debates that's really never been resolved focuses around how many discrete processes ITIL describes. No such single list exists in the ITIL core books. However, section 4.1 of each of the ITIL 2011 core books shows the processes described within that specific book. When we deliver accredited ITIL training, if it is describe in section 4.1 of any of the ITIL core books, then it is considered a "process".

As many of you work on integrating Avaya Aura System and Session Manager into your networks, the case for troubleshooting will indeed occur. There are built in tests in the System Manager that allow you to run tests on 14 different areas, including Session Manager. But what do you do with the results when you get them? I am going to outline six of the most common problems and solutions when installing and implementing System and Session Manager and what steps you can take to troubleshoot and correct the problem.

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.

Your business has been hacked, leaving you with a persistent bot; now what? In this hour-long webinar, security expert David Willson will discuss ways you can eliminate the threat in an act of self-defense or defense of property. As new laws are explored, old ones amended, and solutions sought, you'll take a look at thinking outside the box to give the good guys the advantage-or at least a fighting chance.