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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.

Businesses today are more dependent on technology than ever. And, more than ever, they're looking to IT for ways to improve employee productivity, customer service and innovation. The challenge is that in order to achieve results with technology, IT and the business have to work collaboratively. IT needs to be able to develop the right relationships and communicate with different stakeholders from a business perspective - not a technical one. As a result, the transformation of the IT department has become a top-level priority for many leading organizations. At the same time, business leaders need to strengthen their business technology IQ and play a more significant role in the governance of IT.

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...

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...

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...

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)...

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...

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.

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

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