# Featured Posts

#### Posts from ‘CCENT’

WARNING: You must master subnetting using our course or some other trusted materials before you start using these shortcut approaches. It is a common issue for Cisco candidates to move directly to subnetting shortcuts for the exams without fully understanding exactly how subnetting functions.

ICND1 (CCENT)

Question 2: You have run the ipconfig command and discovered your IP address and mask are 192.168.20.102 and 255.255.255.224. How many hosts are permitted on your subnet?

Step 1: I reference the Powers of Two chart I created on my scratch paper when I encountered the first question. Adding 128 + 64 + 32 = 224. There are 3 bits used for subnetting and that leaves 5 bits for hosts.

2^7=128  |  2^6=64  |  2^5=32  |  2^4=16  |  2^3=8  |  2^2-=4 | 2  ^1=2  |  2^0=1

Step 2: The equation for the number of hosts per subnet is 2^h – 2 where h is the number of host bits. From the chart I see that 2^5  = 32. 32-2 = 30 hosts per subnet! Too easy!

As always, let us know in the comments if you have a quicker approach.

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Thanks to Randy of our CCNA program for this suggestion. Randy wanted some guidance on how to solve the subnetting questions in ICND1 and ICND2 very quickly. The ability to do this is often the difference between a passing score and a failed attempt.

WARNING: You must master subnetting using our course or some other trusted materials before you start using these shortcut approaches. It is a common issue for Cisco candidates to move directly to subnetting shortcuts for the exams without fully understanding exactly how subnetting functions.

For this series of posts, we will use simulated exam questions from ICND1 and ICND2. Well, with all that out of the way – let’s have some fun. You will find that once you “turn the corner” on subnetting, you will pray for many of these questions in the exam. It is an opportunity to solve questions quickly and be 100% convinced that your response is “spot on”.

ICND1 (CCENT)

Question 1: What is the last usable address in the subnet of a host with the address 192.168.1.134 and the subnet mask of 255.255.255.240?

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One of our CCNA students requested some command practice for ICND2 – here is one I put together for him. Please give me feedback in the comments if you find practice tools like this helpful.

ICND2 Command Recall Practice Tool 1

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Are you a CCNP or CCIE student looking to challenge your perfect knowledge of Catalyst switchport commands?

Take the latest SWITCH Command Recall exam by clicking the link below. Good luck – and let us know how you scored in the comments area of this post.

Remember to read, AND TYPE, very carefully! I failed my first attempt due to just plain sloppiness.

SWITCH Command Recall Exam – L2/L3 Ports

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As you may have noticed, INE does a wide variety of training in the Cisco space.      This blog post goes out to all those folks who have recently begun their Cisco training.

This month we delivered new live classes on CCNA and CCNP. We are excited for and encourage our students at every level in their journey.   In that light, we have gathered a collection of Videos Answers, targeted at the CCNA level, with a few topics leaking into security and CCNP.   These videos were primarily created as quick (under 10 minutes each) Video Answers to questions that various learners have had.

Take a look at the list of topics, and if there are 1 or 2 you feel you would benefit from, feel free to enjoy them.

Here are a few of the topics (in no particular order):

• How the network statement really works in IOS
• Setting up SSH
• Initial commands for sanity sake
• Router on a stick

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Are you wondering what the month of August 2010 will bring for INE fans?

Try all new, online bootcamps in the following disciplines:

• MPLS
• BGP
• CCNA
• CCNP
• CCDA

Watch the blog and your email for all of the exciting new details.

Join the INE Experts Online in August

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Here ye, here ye, VTP experts. (We are not referring to the Vandenberg Test Program, although they are very likely experts in their field as well.  )

Can you predict the results of a 3 switch VTP client/server scenario?

SW1-3, are connected, as shown in the diagram.

Here is the initial output of show VTP status, and show VLAN brief on each. Note that SW1 and SW3 are servers, while SW2 is a client.   We will be adding a failure to the network in just a moment. Continue Reading

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This blog post is taken from the INE Resources area Understanding Frame-Relay Traffic Shaping presentation by Brian Dennis.

Overview

Frame-Relay traffic shaping is designed to control the amount of traffic the router sends out of an interface or out of a particular DLCI. Common reasons for Frame-Relay traffic shaping are:

• It allows the router to conform to the rate subscribed with the service provider
• It allows for the throttling of a higher speed site (768K) so that it does not overrun a lower speed site (64K)

Traffic shaping is designed to delay excess traffic, whereas policing is designed to drop excess traffic.

Terminology

• Available Rate (AR) – the actual physical speed of the interface; on a DCE serial interface this is determined by the configured clock rate. On a DTE serial interface, it is determined by the received clock rate. A router will always (by default) try to send out at the AR regardless of the interface bandwidth. AR is also commonly referred to as port speed, line rate, or access rate.

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#### Overview

In this short blog post we are going to present a simple procedure for IPv4 prefix summarization. The procedure is based on the one found in “Optimal Routing Design” book by Russ White, Don Slice and Alvaro Retana, but differs in some respects. The process is three step, and require the use of Windows calculator for ease of computation. No binary breakdowns are involved, just some basic arithmetic. For the sake of simplicity, we skip all proofs, as those are trivial. The same approach could be adopted for use with IPv6 prefixes, provided that decimal arithmetic is replaced with hexadecimal.

#### Scenario

We are going to use an example to demonstrate the method. Here is the task: find the optimal (longest prefix length) summary prefix for the following set of subnets:

```192.168.100.0/22
192.168.101.0/24
192.168.99.0/24
192.168.102.0/24
192.168.105.0/24
192.168.98.0/23
```

This example is taken from the wikipedia article: http://en.wikipedia.org/wiki/Supernet that illustrates the use of binary breakdown for the purpose of address summarization.