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A video covering our Cisco Unified Communications courses - ACUCW1 & ACUCW2 - by Global Knowledge Course Director and Lab Topology Architect Joey DeWiele, a specialist in Unified Communications.
Global Knowledge Course Director and Lab Topology Architect Joey DeWiele, a specialist in Unified Communications, discusses Cisco Unity, Unity Connection & Unity Express.
Chief Technical Architect Craig Brown discusses the Windows 7 certification and skills tracks available to Global Knowledge students.
Course director Jim Thomas explains how our custom labs, which utilize external hosts, ISR routers, and DMZ, provide a real-world environment for students.
New in Windows Server 2012 is the Unified Remote Access (URA) role. In Windows Server 2008 R2, DirectAccess and Routing and Remote Access Service (RRAS) were two separate roles. In fact, they could not be co-located on the same server. In Windows Server 2012, DirectAccess and RRAS can be co-located, allowing for what is now legacy remote access VPN client connectivity (L2TP/IPsec, PPTP, and SSTP). This means that the Unified Remote Access provides DirectAccess, Remote Access VPN, and site-to-site VPN and can now serve as your complete remote access solution.
Rodger Foster, our senior Cisco instructor, reviews how multiple gateways are used to provide redundancy in the network.
There exists a need to properly read, deploy, and examine the results of Group Policy. By its architecture, Group Policy Deployment to the Clients or Servers can be erratic and latent, or even non-existent throughout your Enterprise Organization, frustrating Administrators who are rolling out the Group Policy to Client or Server computers. To help mitigate this behavior, I compiled these insights into a two part series from real-world examples, experiences, and fixes that have worked for me. I know that these Tips and Tricks will work for you, too.
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.
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.
Some of you might just be starting out as a database administrator and need to know what a basic Transact-SQL query is for Microsoft SQL Server 2012, others might already be creating database objects. Either way, we put together a list of a few terms regarding Microsoft SQL Server that any database administrator should know.
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).
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.
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.
Network security is everyone's concern, and this applies to computer security as well. Many security breaches occur due to user ignorance of basic security principles, not malicious intent. Network and computer security are like an onion - there are multiple layers. Good security begins with understanding what you can do to keep your systems safe and implementing a layered approach. If you depend on one program or feature to secure your computer, then when (not if, but when) that dependency is breached, you may have personal information stolen or even have your computer taken over.
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.
Global Knowledge Course Director and Lab Topology Architect Joey DeWiele, a specialist in Unified Communications, explains QoS.
The 'Go Further' video is an testimonial to the value of Microsoft Certification as a validation of technical skills. Whether you're just starting your IT career, or looking to advance it, certification can make a huge impact. Take a look at the video, and hear the stories of real MCPs.
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.
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.
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.
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.
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.
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.
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.
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.
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...