Posts Tagged ‘Cisco’

CCNA Voice Tutorial – DHCP and the IP Phone Boot Process

by Chris Bryant - 15 October 2009

Just as our switches and routers have certain tests and procedures they run when they boot, so do Cisco IP Phones – but of course, there’s a major difference or two between the Phone and router boot processes!

Here’s the basic boot procedure for a Cisco IP Phone:

As you’d expect, the first step is to physically connect the Phone to a switch port. The Phone can receive its power via Power Over Ethernet (PoE) if the Phone and Switch agree on the PoE method to be used. Originally called “inline power”, PoE allows the power to be sent through the copper cable to the connected device.

Our old friend Cisco Discovery Protocol enters the picture now, as its CDP that tells the Phone what Voice VLAN to use. Be sure CDP is running on the switch port that’s connected to the IP Phone, as it’s commonplace to disable CDP.

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CCNA Security Exam Tutorial – When It’s Good to Add Salt

by Chris Bryant - 2 February 2009

When you started studying for your CCNA certification exam, one of the very first things you learned was the major difference between the enable password and the enable secret – the enable secret is encrypted by default, where the enable password is just sitting there in clear text, waiting to be read!

When you look at the enable secret in a Cisco router configuration, it looks like it would be impossible to guess. After setting the enable secret on this router to the word security, here’s how it appears in the configuration:

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Cisco CCNP ISCW Certification Exam Tutorial – The Key Difference Between IPS And IDS

by Chris Bryant - 4 August 2008

When it comes to your Cisco CCNP certification exams, success is in the details, and that’s particularly true of your ISCW exam.

You’re going to need to know all the vital details of configuring and troubleshooting Cisco’s Intrusion Prevention System (IPS), both from the command line and via Security Device Manager (SDM).

We first need to draw a clear line between the operation of the Intrusion Prevention System and the Intrusion Detection System (IDS). Those terms sound similar, but they’re quite different in operation.

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