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Cisco provides a wide array of connectivity and isolation tools within the datacenter. This white paper addresses Virtual Routing and Forwarding (VRF), which is a Layer 3 isolation mechanism for routing protocols.

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.

Rodger Foster, our senior Cisco instructor, reviews how multiple gateways are used to provide redundancy in the network.

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.

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.

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.

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.

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 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...

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:

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.

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.

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?”

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.

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.

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.

This Webinar will focus on addressing the issues of an unsecure data center network and how to address the security concerns with Cisco ACI. The key components of how to create an ACI whitelist will be covered. View slide deck>>

This webinar will focus on addressing the issues of an unsecure campus network and how to address the insecurity with ISE. We then will look at how Cisco ISE can add security to devices beyond initial connectivity. View the slide deck>>

This webinar focuses on addressing the issues of an unsecure campus network and how to address the insecurity with 802.1X. We then will look at how Cisco ISE can centralize campus access with 802.1X. View the slide deck>>

Cisco Unified Computing Solution (UCS) is a very popular and powerful solution. Cisco continues to provide updated UCS management options for the full range of data center installations.

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.

For organizations getting started with RHEL, Red Hat Training has developed a series of courses to develop the skills needed for basic administration and configuration of Red Hat Enterprise Linux. These courses introduce key command line concepts and enterprise-level tools, laying the foundation for the rapid deployment of Red Hat Enterprise Linux. The curriculum also introduces the basic administration skills needed for resolving configuration issues and integrating Red Hat Enterprise Linux systems with other existing environments. View the slide deck>>

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...

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.

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”.

Global Knowledge instructor Doug Notini discusses the benefits of our FIREWALL 2.0 - Deploying Cisco ASA Firewall Solutions course.

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

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.

A Dynamic Multipoint Virtual Private Network (DMVPN) can be used with other networks like Multiprotocol Label Switching (MPLS), but streaming multicast is accomplished quite well using "Default" and "Data" Multicast Distribution Trees (MDTs) with MPLS.

The Red Hat® Learning Subscription delivers 12-months of unlimited access to all Red Hat Online Training courses. The Standard RHLS subscription is a higher tier with access to 5 certification exams and up to 2 retakes.

In numerous Cisco classes, students learn about IPv4 and IPv6 address subnetting, complex subnetting, variable length subnet masking (VLSM), summarization, prefix routing, and address aggregation. These are valuable skills. In order to apply these skills efficiently, a network designer should possess one additional skill. Planning the IP address space for a Class A or B IPv4 address is necessary to apply the complex skills listed above properly. Complex subnetting, VLSM, and IP address summarization can be implemented simply and efficiently with proper planning.

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

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.

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.

Course director Jim Thomas explains how our custom labs, which utilize external hosts, ISR routers, and DMZ, provide a real-world environment for students.

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...

In the spring of 2013, Cisco announced major updates to their Cisco Certified Network Associate (CCNA) curricula, including a new version of the CCNA Routing and Switching exam (200-120 CCNA). This paper provides a review of the CCNA Routing and Switching exam's critical concepts, as an aid to students preparing to pass the latest version of the CCNA Routing and Switching exam.

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).

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.

Cisco Collaboration Systems Release (CSR) 10.6, along with CUCM 10.5(2), enhances the user and administrator experiences and interactions. In many cases, a change to one product may necessitate changes to other products. For example, where the deployment options for video conference control changed to place all control behind the Telepresence Conductor, Cisco Prime Collaboration management tools had to be updated to reflect this new deployment approach. As new endpoints are added, CUCM and Prime Collaboration both needed to be updated to reflect the new endpoints.

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).

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.

Watch this recorded webinar to understand how Cisco Intent-Based Networks and SDN technologies will transform your network to be the cornerstone of your digital success.

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...

The Cisco Unified Collaboration solutions offer anytime, anywhere access for organizations who need instant access to clients, vendors and remote employees. Cisco products enable authorized external users to connect to corporate resources, create different user groups and manage large scale deployments. Learn how Cisco Unified Collaboration infrastructure products can help you provide everything from call control which provides signaling and dial plan support to the expressway series providing firewall traversal for external access.

This paper explains uplink strategies for traffic coming in and out of a Cisco Unified Computing Solution (UCS) chassis. An uplink can be Ethernet, Fibre Channel, or FCoE and is a physical connection on the FI that leaves the UCS domain directed away from the B Chassis.

Meet Global Knowledge course director and lab topology architect Joey DeWiele, a specialist in Unified Communications. Joey will walk you through the benefits of our exclusive Cisco UC lab architecture - a more scalable and stable approach to the all-important labs featured in unified communications courses. Our labs feature upgraded hardware and software including Custom Lenovo T61 PCs, 7965 IP Phones, 3560 Switches and Call Manager 7. With our flexible UC architecture, students are able to view and experience the full lab architecture regardless of which Cisco UC course they are taking or the skill set they are seeking. The lab architecture features a realistic network with redundant environments that are made rich with multiple machines, pre-deployed tools with shortcuts, online documentation that is particular to individual pods, and multiple OS support for all virtual machines (Windows, Linux, VMware).

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.

This overview of the Cisco On-Demand Learning portfolio covers the various products and solutions available. Including all access collections, certification e-camps, and individual course titles.  With Cisco On-Demand Learning you can train your workforce easily and effectively.

Network switching skills are fundamental to administering and maintaining computer networking. This webinar reviews fundamental networking skills from a Cisco perspective. Technical professionals looking to take the next step into Cisco specific networking technologies will benefit from this information. View the slide deck>

Need to control the digits contained in the telephone number that enter or leave a gateway? Digit manipulation involves adding, subtracting, and changing telephone numbers. You can manipulate calling numbers, called numbers, and redirecting numbers, as well as the numbering plan and ISDN number type. Learn about the techniques that are applied to incoming or outgoing calls, or globally to all calls. You can also manipulate telephone numbers before or after a dial peer is matched.

Learn how Cisco FabricPath combines the benefits of Layer 2 Switching and Layer 3 Routing, allowing for the scalability and flexibility of Layer 2 while supporting traditional Layer 3 components such as optimal paths, equal cost multipath routing and a Time to Live (TTL) field.

Instructor Carol Kavalla talks about the advantages of taking a Cisco Data Center Unified Fabric Implementation class from Global Knowledge.

Security attacks have become more advanced; therefore, security solutions have needed to evolve to deal with those threats. Cisco's acquisition of Sourcefire brings a new paradigm to the security landscape. No longer is security a one-time, instantaneous event. Security now is threat based, network cognizant, and continuous. All organizations, public and private, need to be aware not only of the constantly changing threat environment, but must be prepared to respond in kind.

Your clients, vendors and workforce don't always operate in the same building, state or country. Cisco Collaboration Endpoint products make communicating with your counterparts across town or on the other side of the world easy. This white paper provides you with product specifications and capabilities for Cisco's phone, desktop, and large screen immersive videoconferencing options.

On February 17, 2015, Cisco announced changes to the existing voice and video certifications and detailed the new collaboration certification portfolio. This white paper provides an overview of the changes to Cisco certifications with respect to voice and video, outlining dates, and deadlines that may affect your certification process.

Understand the two training options to prepare for the CCNA Routing and Switching certification - traditional and accelerated. Global Knowledge allows you to learn at your pace. The traditional training path features two courses, ICND1 and ICND2, and ten days of training. The accelerated training path combines the content found in ICND1 and ICND2 into a single 5 day course, the CCNAX Routing and Switching Boot Camp. Learn which option is best for you.

Global Knowledge Course Director and Lab Topology Architect Joey DeWiele, a specialist in Unified Communications, explains the difference between Cisco's Call Manager Express & Call Manager.

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.

This webinar is examining the process of how to best prepare for the Cisco Certified Network Professional in Enterprise skill set. We will look at the process to become certified including which exams to take; look at the available resources for study, including the blueprint for the exams and courses that are applicable. We will look at why someone might want to get certified as a CCNP Enterprise. We will also examine the process to maintain the certification. View slide deck>>

What path you decide to take to earn your Cisco Certified Network Associate (CCNA) Routing and Switching certification will depend on a number of factors including your availability, willingness to work long hours and your ability to absorb a lot of information in a short period of time. This white paper includes self-assessments and training recommendations to help you figure out if taking the CCNAX Routing and Switching Boot Camp or taking two separate ICND1 and ICND2 courses is the best fit for you.

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.

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.

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...

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...

In this second webinar in a series dedicated to building up network security, network security specialist Catherine Paquet will fill you in on advanced threat protection that integrates real-time contextual awareness, intelligent security automation and superior performance with industry-leading network intrusion prevention, Sourcefire.

Despite advances in security, hackers continue to break through network defenses. In this hour-long webinar, network security specialist Catherine Paquet will examine the favorite methods and targets of hackers and will introduce you to the different categories of security technologies. In this foundational presentation, you will learn about the benefits of security solutions such as firewalls, VPNs, IPS, identity services and BYOD.

The process of learning how to subnet IP addresses begins with understanding binary numbers and decimal conversions along with the basic structure of IPv4 addresses. This paper focuses on the mathematics of binary numbering and IP address structure.

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.

This webinar will look at Border Gateway Protocol and explore why we have the protocol; how its involved and how it works. We will look at how and where BGP is used in today’s networks and Internet. We will look at the basics of configuring it and some not so basic configurations.  

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.

Learn more about the many benefits of Global Knowledge's Virtual Classroom Live training.

Diane Teare, Global Knowledge's Cisco Course Director, discusses the advantages to taking our CCNA Boot Camp.

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.

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...

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 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...

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...

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.