IP Subnetting Tips&Tricks - Study + Workbook Package

Hi,

Our Team put together 2 IP Subnetting Books to help cut through the clutter and confusion of subnetting.

It's hard work, but it's work that pay's off on the Job when your boss asks you to subnet an address space. :-) Once you master it, it is just practice and speed.

The Study Guide + Workbook Package helps you accomplish this. It takes you step by step with explanations.

So what's in the package?

##Learn IPv4 Subnetting with Step by Step Techniques

-Quickly calculate subnets and hosts with number line technique

-Two books - Study Guide & Workbook Package

-Proven Industry Tips and Tricks from the Field

-Easy to understand Techniques

##Ideal for: Network Administrators - working on Cisco, Juniper, Foundry and other Platforms Students - pursuing Cisco CCNP/CCNA, Juniper JNCIA/JNCIS Job Retraining - a little rusty or just needing more practice

##Content:

-Real-world job tasks on subnet allocation

-Step-by-step explanations

-Workbook examples and explanations

-Number line tricks and tips

-Allocating number of subnets given an aggregate network

-Diagrams showing address assignments in real-world environments

-Subnet zero usage

-Point to point tips

-Address summarization techniques

-Determine number of hosts and subnets

-Network allocation techniques

##What you'll get:

**Two Books (PDF format)**

1. Study Guide - subnet tutorial, tips/techniques/tricks and diagrams
2. Workbook - explanations, real world topologies and diagrams

##Cost: $38

*Free shipping - available immediately. I will email you the document directly.

**Email for purchase - Accepting Payments via Paypal. snipped-for-privacy@gmail.com

I haven't seen your book, but in my experience any clutter and confusion is entirely in people's heads and can be dispelled quite easily.

It's not at all hard. You just need to understand how computer thinks in bits and then it all becomes very obvious. Trust me, I've had experience of this and I can explain it to most people in about 5 minutes.

Sam

Check it out: This is FREE!

********** BINARY METHOD: ********** Given an IP address and subnet mask: 192.168.50.3 255.255.240.0 You convert to binary: 11000000.10101000.00110010.00000011 11111111.11111111.11110000.00000000 If you break the IP address into its network portion host portion based on where the 1's and 0's in the subnet mask are seperating the address: 11000000.10101000.00110000.00000000 = 192.168.48.0 00000000.00000000.00000010.00000011 = 0.0.2.3 CHECK: Add these two decimal format IP address portions together, and you end up with the original address: 192.168.48.0 0.0.2.3 +_____________ 192.168.50.3 Now that you have verified your binary math, convert all of the host bits in 192.168.48.0 from 0's to 1's: 11000000.10101000.00111111.11111111 = 192.168.63.255 Figure up the number of binary bits in the host portion and figure up 2 to the nth power for that value: 2^12 = 4096 Now you have determined that the IP address is in a subnet with the following information: Lowest IP address: 192.168.48.0 Lowest IP address: 192.168.63.255 Number of IP addresses in the subnet: 4096 with only 4094 host addresses available

********** MY METHOD:

********** Given an IP address and subnet mask: 192.168.50.3 255.255.240.0 Perform some odd subnet math subtracting each octet from 256 and then multiplying the differences together: 256 256 256 256 255 255 240 0 -_________________ 1 x 1 x 16 x 256 = 4096 Now take that "funny number" in the subnet mask subtracted from 256 and start counting ranges from 0 by that number and then look for that the value in the corresponding octet of the IP address: 256 - 240 (3rd octet of subnet mask) = 16 Couting by 16s, looking for 50 (3rd octet of IP address): 0...15, 16...31, 32...47, 48...63 FOUND 50! Insert those low and high ranges with a 0 and 255 after them, respectively: 192.168.*48*.*0* 192.168.*63*.*255* That is it. You just determined the low and high IP address in a range and the size of the range - no binary math!

I still remember the day that I "got" subnetting :-) "Teach Yourself TCP/IP In 24 Hours" by SAMS Publishing was what did it for me, lo these many moons ago :-)

Yup. And the first step is: "forget classes". It's depressing to see how many schools still teach the old, obsolete classful IP addressing scheme and then try to add subnetting on top of that, when starting directly with CIDR would be so much easier to grasp for the students.

Yep. Mind you the OP's advert doesn't mention classes so perhaps the message is getting through. Anyone want to spend $38 to find out? :-)

Sam

These are the same classes that still insist on teaching OSI!

You don't need to convert anything to binary where the mask is 255 or 0. For the octet which isn't 0 or 255 you only need 7 values for the mask corresponding to 1 to contiguous bits at the left. If you can't remember them then stick them on your wall, or on a card in your wallet, or in a file somewhere.

Again you only need to do this for one octet = 48+2=50, and only if your mask length is not a multiple of 8.

Again you only need to do max one octet, the ones to the left of the octet where the mask falls are the same as the address, the ones to the right are 255.

Again you can have a table or use a calculator if you can't remember the numbers.

Hooray!

Any mask octet that is 255 is irrelevant so you can ignore it.

Jolly good - you did your math on one octet, just like you could do with the binary version, except that you've done it in decimal and by trial and error, and people need to know or calculate multiples of 16 (or 32 or 64 or 128, or 8 or 4 or 2 - how many multiples of 4 do you have to test to find the enclosing range of 233, say?).

And where did you check your math?

But why are you scared of binary math[1]? I need to remember 1, 2, 4,

8, 16, 32, 64 and 128, and (in the other direction) 192, 224, 240, 248, 252 and 254 (0, 255 and 256, of course). You need to remember all the multiples of 4, 8, 16 etc up to 256. You can work those numbers out, but I can work out mine too.

I've never been able to see why this is any more memorable or understandable than knowing how the computer actually does it internally. Could someone who prefers this method explain why it's better?

Sam

[1] On this side of the pond we say binary maths, just to be awkward.

We learned the "magic number" technique in my class, but I find that I do much better thinking in binary and using ANDing. I can still use the trick to check if I need to, but it helps me to visualize the subnet and host bits and how they divide.