26 August 2015 RE Meyers, Ms.Ed., CCAI CCENT Exam Success Strategies Accurate and Fast IP Address Problem Solving Part 1: Building A Subnet Answer Key

26 August 2015 RE Meyers, Ms.Ed., CCAI Objective  After successfully completing the activities in this presentation, the student will be able to construct an IP Addressing “answer key” for 2 octets with no outside assistance that includes: CIDR Subnet mask values Powers of two and their equivalent values Binary value for each bit of each octet

26 August 2015 RE Meyers, Ms.Ed., CCAI Subnets and VLSM Problem Solving  Given enough practice and time, networking instructors and students will be able to solve all subnet and VLSM problems on an exam.  On a certification exam, the biggest challenge is time. Certification exam time management is a critical skill for success. Spend the least amount of time on each question. Under pressure of a ticking clock, anyone can choke and freeze. Accurate answers can be found quickly! It requires patience and practice. Did I mention practice? You must practice. A lot.

26 August 2015 RE Meyers, Ms.Ed., CCAI IP Address Problem Solving  “What do I need to know first?”  You must be 100% locked in converting decimal numbers 0 – 255 to binary, and eight bit binary to decimal accurately and quickly.  If not, then this presentation will not help much.  Practice binary-decimal-binary conversions until you can do them easily.

26 August 2015 RE Meyers, Ms.Ed., CCAI Subnets and VLSM Problem Solving  What else do I need to know?”  This is not a presentation on how to subnet or how to develop VLSM IP addresses.  Both of those skills are presumed to be taught, practiced, and accomplished already.  Practice is the only way to become proficient at subnetting and VLSM addressing. Very few people actually like to practice. Nobody likes to fail. Practice reduces failure to a small percentage. Your choice.

26 August 2015 RE Meyers, Ms.Ed., CCAI Critical Reading  Many complain that Cisco exams are “reading comprehension exams” and not technical exams.  Anyone who works at a help desk will confirm that clear communication is the first hurdle to solving any problem.  This presentation will focus on getting the correct addresses. Part 3 is about picking out the words that are important, and those that are not.

26 August 2015 RE Meyers, Ms.Ed., CCAI IP Problem Solving: Use the Answer Key  Every certification exam allows you to write notes using given pen and paper.  Usually these are a erasable pen and an 8”x10” piece of laminated paper or card stock.  Before you start the exam, and the ticking clock, create your IP Addressing Answer Key.  The exam problems will then be easy to solve.

26 August 2015 RE Meyers, Ms.Ed., CCAI Building the Subnet Answer Key

26 August 2015 RE Meyers, Ms.Ed., CCAI Building the Subnet the Answer Key  Watch this presentation once or twice without writing anything down.  Then click through it while doing all the steps on paper.  You’ll be tempted to just print it the key. Don’t!  The point is to be able to write the key out during a certification exam. You don’t get to bring a pre-printed key in with you!  If you can’t create it from a blank page, then you are no better off than before.

26 August 2015 RE Meyers, Ms.Ed., CCAI Building an the Subnet Answer Key: Step 1 1. Take your paper and set it long ways (landscape) on the table.  At an inch down from the top, draw a dotted line to the bottom, and put a big dot at the top of it.

26 August 2015 RE Meyers, Ms.Ed., CCAI Building an the Subnet Answer Key: Step 2 2. Using the width of a finger, draw 8 lines down on EACH side of the center dotted line  Each column, between the lines, is one of eight binary bits to the right of the dot, and eight bits to the left.

26 August 2015 RE Meyers, Ms.Ed., CCAI Building an the Subnet Answer Key: Step 3 3. At the top of the center line dot, write /24.  This dot is the divider between the octet on the right and the octet on the left.  The right is the fourth octet of an IP address  The left is the third octet of an IP address  /24 is the CIDR notation for the divider between the 3 rd and 4th octet, and the default for a Class C address. /24

26 August 2015 RE Meyers, Ms.Ed., CCAI Building an the Subnet Answer Key: Step 4 4. Complete the rest of the CIDR notations  From center to right, add one for each line  From center left, subtract one for each line /24 /20/21/22/23/25/26/27/28/29/30/19/18/17/31/16 /32

26 August 2015 RE Meyers, Ms.Ed., CCAI Building an the Subnet Answer Key: Step 5 5. About 1 1/2 inch down from the CIDR in each binary bit column, write the decimal equivalent of each binary placeholder in each octet.  From right to left: 1, 2, 4, 8 …etc. Remember all you have to do is start from 1 and multiple by 2.  Restart after the /24 dot.  Then draw a horizontal line under the numbers 4. Complete the rest of the CIDR notations  From center to right, add one for each line  From center left, subtract one for each line /24 /20/21/22/23/25/26/27/28/29/30/19/18/17/31/16 /

26 August 2015 RE Meyers, Ms.Ed., CCAI Building an the Subnet Answer Key: Step 6 6. Right above the decimal placeholder numbers, write the power of 2 numbers.  From right to left, 2 0, 2 1, 2 2, etc. all the way to the end on the left.  Do NOT restart at the /24 dot! 5. About 1 1/2 inch down from the CIDR in each binary bit column, write the decimal equivalent of each binary placeholder in each octet.  From right to left: 1, 2, 4, 8 …etc. Remember all you have to do is start from 1 and multiple by 2.  Restart after the /24 dot.  Then draw a horizontal line under the numbers 4. Complete the rest of the CIDR notations  From center to right, add one for each line  From center left, subtract one for each line /24 /20/21/22/23/25/26/27/28/29/30/19/18/17/31/16 /

26 August 2015 RE Meyers, Ms.Ed., CCAI Building an the Subnet Answer Key: Step 7 7. Above the powers of 2 enter the decimal equivalents of each.  Start at the right under 2 0 with “1” and just multiply by 2 for every bit column as you go to the left. 6. Right above the decimal placeholder numbers, write the power of 2 numbers.  From right to left, 2 0, 2 1, 2 2, etc. all the way to the end on the left.  Do NOT restart at the /24 dot! 5. About 1 1/2 inch down from the CIDR in each binary bit column, write the decimal equivalent of each binary placeholder in each octet.  From right to left: 1, 2, 4, 8 …etc. Remember all you have to do is start from 1 and multiple by 2.  Restart after the /24 dot.  Then draw a horizontal line under the numbers 4. Complete the rest of the CIDR notations  From center to right, add one for each line  From center left, subtract one for each line /24 /20/21/22/23/25/26/27/28/29/30/19/18/17/31/16 /

26 August 2015 RE Meyers, Ms.Ed., CCAI Building an the Subnet Answer Key: Step 8 8. Last step: Enter the subnet mask numbers for each binary bit column in each octet from left to right.  Start with 128 and then add the next column bit value to get the new entry.  Continue left to right and be sure to restart at 128 after the /24 dot line. 7. Above the powers of 2 enter the decimal powers of 2 numbers  Start at the right under 2 0 with “1” and just multiply by 2 for every bit column as you go to the left. 6. Right above the decimal placeholder numbers, write the power of 2 numbers.  From right to left, 2 0, 2 1, 2 2, etc. all the way to the end on the left.  Do NOT restart at the /24 dot! 5. About 1 1/2 inch down from the CIDR in each binary bit column, write the decimal equivalent of each binary placeholder in each octet.  From right to left: 1, 2, 4, 8 …etc. Remember all you have to do is start from 1 and multiple by 2.  Restart after the /24 dot.  Then draw a horizontal line under the numbers 4. Complete the rest of the CIDR notations  From center to right, add one for each line  From center left, subtract one for each line /24 /20/21/22/23/25/26/27/28/29/30/19/18/17/31/16 /

26 August 2015 RE Meyers, Ms.Ed., CCAI Completed Subnet Answer Key  Build an answer key in 8 steps. Ironic, eh? 7. Above the powers of 2 enter the decimal powers of 2 numbers  Start at the right under 2 0 with “1” and just multiply by 2 for every bit column as you go to the left. 6. Right above the decimal placeholder numbers, write the power of 2 numbers.  From right to left, 2 0, 2 1, 2 2, etc. all the way to the end on the left.  Do NOT restart at the /24 dot! 5. About 1 1/2 inch down from the CIDR in each binary bit column, write the decimal equivalent of each binary placeholder in each octet.  From right to left: 1, 2, 4, 8 …etc. Remember all you have to do is start from 1 and multiple by 2.  Restart after the /24 dot.  Then draw a horizontal line under the numbers 4. Complete the rest of the CIDR notations  From center to right, add one for each line  From center left, subtract one for each line /24 /20/21/22/23/25/26/27/28/29/30/19/18/17/31/16 /

26 August 2015 RE Meyers, Ms.Ed., CCAI Review of Each Column and Row 7. Above the powers of 2 enter the decimal powers of 2 numbers  Start at the right under 2 0 with “1” and just multiply by 2 for every bit column as you go to the left. 6. Right above the decimal placeholder numbers, write the power of 2 numbers.  From right to left, 2 0, 2 1, 2 2, etc. all the way to the end on the left.  Do NOT restart at the /24 dot! 5. About 1 1/2 inch down from the CIDR in each binary bit column, write the decimal equivalent of each binary placeholder in each octet.  From right to left: 1, 2, 4, 8 …etc. Remember all you have to do is start from 1 and multiple by 2.  Restart after the /24 dot.  Then draw a horizontal line under the numbers 4. Complete the rest of the CIDR notations  From center to right, add one for each line  From center left, subtract one for each line /24 /20/21/22/23/25/26/27/28/29/30/19/18/17/31/16 / Top row: CIDR notation for each bit column Second row down: Normal subnet mask number for each bit column Third row down: Decimal values for the powers of two for each bit column Fourth row down: Power of two for each bit column, right to left. Always start with 2 0 and not 2 1 ! Fifth and last row down: Normal binary bit value for each column

26 August 2015 RE Meyers, Ms.Ed., CCAI Now What?  Did I mention that the only way to solve subnet/VLSM problems quickly and accurately was to practice?  First, you need to practice building this key until you can do it quickly and accurately.  The next presentation in this series shows how to use the answer key to solve subnet problems, followed by VLSM.

26 August 2015 RE Meyers, Ms.Ed., CCAI End