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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).

“Twisted Pair” is another way to identify a network cabling solution that’s also called Unshielded Twisted Pair (UTP) and was invented by Alexander Graham Bell in 1881. Indoor business telephone applications use them in 25-pair bundles. In homes, they were down to four wires, but in networking we use them in 8-wire cables. By twisting the pairs at different rates (twists per foot), cable manufacturers can reduce the electromagnetic pulses coming from the cable while improving the cable’s ability to reject common electronic noise from the environment.

Good question! There are lots of networks, so I’m sorry to say that it depends. Let me explain. The smallest computer-based networks are usually PANs or Personal Area Networks. They can connect a wireless keyboard, mouse, or other devices to a computer. You may find them wirelessly linking a printer to your computer. You may have noticed these all include wireless connections. A PAN most often uses wireless technologies like infrared and Bluetooth, so it is really a WPAN (Wireless Personal Area Network).

CompTIA has raised the bar for Network+ candidates. The new certification exam has significant changes to the five "domains" or knowledge areas with new content related to security, cloud, data-center and operational concerns and troubleshooting. There is also a greater emphasis on wireless networking and VoIP. Use this white paper to help you gain an overview of what's new and what's different.

One of the main weapons of organized crime on the Internet is the use of junk email, also called spam. Hackers use spam for a number of purposes such as selling counterfeit products (medicines, particularly) to steal your personal or financial information, or to infect your computer with spyware and malware. This malicious software can then hijack your computer and your Internet connection to help propagate itself.

Answer? When it is flagged as a retransmission in Wireshark!

I recently responded to a message on LinkedIn from a regular reader of this blog. He asked several questions which I will answer over the course of several posts. As part of his first question, he described a strategy report that his group is producing. The audience for this strategy report considers ITIL important to the future of their business, and so he must describe which ITIL processes his data center operations group works most closely with.

This year, CISSP-certified IT professionals have the third highest global salary ($116,573) and the 10th highest in North America ($123,815). This is nothing new—CISSP has ranked in the top 10 in the U.S. each year since 2015, even coming in first in 2018. CISSP is a top-paying certification year after year. But how has it remained so relevant and valuable?

Watch this recorded webinar as CompTIA’s chief technology evangelist and Global Knowledge’s federal sales director discuss how pentesting has morphed.

Does your company have a risk management program? In this hour-long webinar, cybersecurity expert and Global Knowledge instructor David Willson will explain why you should. In light of recent breaches at Target, Nieman Marcus, Michaels, Yahoo, and a growing list of others, we're learning that FBI Director Mueller was right when he said getting breached is not a matter of if, but when. While having a risk management program may not prevent a breach, it can certainly lower the risk of one, ensure compliance, and reduce or even eliminate your liability if a breach does occur, enabling you to recover quickly and to protect your reputation. Beyond explaining the importance of a risk management program, David will tell you how to implement one, including conducting a basic risk assessment, policies you'll need, and training your workforce.