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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 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.

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.

Risk is something we deal with on a daily basis. Living in New Jersey and having the occasional storm, I’ve recently performed my own risk assessment determining the value of certain assets and activities and made a decision on what I was willing to spend to reduce risk to what I perceived as an acceptable level. My management of risk was a rather simple case. Sure, in my revised business continuity plan for my home, I’ll make sure that I have more D cell batteries, have my garage door adjusted so it opens manually again, more food I can heat on a stove and that doesn’t rely on refrigeration, and finally I’ll consider a whole house gas generator that uses natural gas, which has always been available to power critical systems like the sump pump in my basement. What if, however, I was a really large business? One with lots of components and interdependencies that require a tight integration in order to succeed? How and where can a large volume of information necessary to management, business continuity, and disaster recovery be correlated and communicated to those individuals who, because of their roles and responsibilities, need to make the critical decisions regarding the management of risk?

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:

The OSI model is a conceptual tool used to discuss and describe network functions. The use of a standard reference model is essential to communicating ideas as well as creating 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.

While the last few years have brought about many great advances in IT and network technology security and risk management have a critical point. There is a host of new concerns the IT security manager must be concerned with, including social networking, mobile, cloud, and information sharing. This has unleashed a new wave of change and potential risk. Risk management is required to deal with these emerging technologies and should provide the rationale for all information security activities within the organization. You can think of risk management as the process of ensuring that the impact of threats and exploited vulnerabilities is within acceptable limits at an acceptable cost. Risk management requires the use of countermeasures. Countermeasures can include any process that serves to reduce threats or vulnerabilities.

Dell SonicWALL's CSSA (Certified SonicWALL Security Administrator) exam is an open book, online certification exam that certifies a student’s understanding of the SonicOS Unified Threat Management (UTM) operating system. The exam tests a student’s network security knowledge, and their ability to use the GUI menu structure for configuration of standard network security scenarios.

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.

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.