Resource Library

For several years, most news articles about a computer, network, or Internet-based compromise have mentioned the phrase "zero day exploit" or "zero day attack," but rarely do these articles define what this is. A zero day exploit is any attack that was previously unknown to the target or security experts in general. Many believe that the term refers to attacks that were just released into the wild or developed by hackers in the current calendar day. This is generally not the case. The "zero day" component of the term refers to the lack of prior knowledge about the attack, highlighting the idea that the victim has zero day's notice of an attack. The main feature of a zero day attack is that since it is an unknown attack, there are no specific defenses or filters for it. Thus, a wide number of targets are vulnerable to the exploit.

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:

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.

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.

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.

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?

Learning how to program and develop for the Hadoop platform can lead to lucrative new career opportunities in Big Data. But like the problems it solves, the Hadoop framework can be quite complex and challenging. Join Global Knowledge instructor and Technology Consultant Rich Morrow as he leads you through some of the hurdles and pitfalls students encounter on the Hadoop learning path. Building a strong foundation, leveraging online resources, and focusing on the basics with professional training can help neophytes across the Hadoop finish line.

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: