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What do you think is the most confusing thing about IP subnetting? Do these illustrations help demystify the concepts effectively?
For most its the Anding, for others its remembering what /24 means.
Some of those diagrams are usefull, though I'm not sure about the first one.
Some of those diagrams are usefull, though I'm not sure about the first one.
I've actually laid out VERY large and complex network using that first ruler. It's a visual tool for designing complex variable length subnets, supernets, and summarized subnets. That especially comes in handy for router, switch, and firewall engineers. Using the AND function and the /24 subnets is the basic stuff. The MCSE certifications don?t go that far in to subnet layout and design like the Cisco certification exams.
hey hows it going. do you know of additional areas where i can pick up more how to on subnetting. i did not get the ruler explanation
http://www.lanarchitect.net/Designs/SubnetRuler/SubnetRuler.html
The ruler let's you visually map and subnet without doing any math. See if the animation makes it a little easier.
The ruler let's you visually map and subnet without doing any math. See if the animation makes it a little easier.
I just wanted to express my gratitude for the subnet ruler. I am going to school to earn a Bachelors in IT and I am currently in a networking class. Having a visual aid like this sure does help to understand the subnetting guidelines. Thanks again for sharing.
OK, I'm still confused on this one. If 172.16.0.0 is a class B, shouldn't it be a /16?
I would have thought that 172.20.0.0/12 would run from 172.20.0.0 to 172.20.15.255. Where am I getting lost? The other examples make total sense to me.
I would have thought that 172.20.0.0/12 would run from 172.20.0.0 to 172.20.15.255. Where am I getting lost? The other examples make total sense to me.
Classes are just arbitrary borders and just adds confusion for students. Modern routers by default ignore the concept of classes and Cisco routers implement the default configuration of "IP classless" to ignore classes. Turning off that command and honoring classes can cause HUGE problems because the router will assuming anything starting with an IP below 127 is automatically a /8 which means the router (if it's running dynamic routing) will hijack massive numbers of routes. I've been the victim of this kind of sloppy configuration from affiliate companies who manage to screw up my routes big time because they were running in classful mode rather than classless mode.
Now when you see 172.16.0.0/12 (not 172.20.0.0/12), that is a private block of sixteen B-sized blocks. That goes all the way from 172.16.0.0 to 172.31.255.255. That second octet has 16 variations and each one of those represents a B-sized block of 2^16 addresses.
Now when you see 172.16.0.0/12 (not 172.20.0.0/12), that is a private block of sixteen B-sized blocks. That goes all the way from 172.16.0.0 to 172.31.255.255. That second octet has 16 variations and each one of those represents a B-sized block of 2^16 addresses.
At the end of the article, it says that if you assigned 4.3 billion people 4.3 billion IPv6 addresses each, you'd have 18 million trillion IPv6 addresses left. Actually, you'd have 18 million trillion times more addresses than you've used, which means you'd have (18 million trillion - 1) * 4.3 billion ^ 2 addresses left.
Using the notation NeM = N*10^M:
4.3e9 squared is about 18e18, which is nothing compared to the 3e38 addresses available in IPv6.
The key is that 3e38 - 18e18 still equals 1e39, not 3e38/18e18.
Using the notation NeM = N*10^M:
4.3e9 squared is about 18e18, which is nothing compared to the 3e38 addresses available in IPv6.
The key is that 3e38 - 18e18 still equals 1e39, not 3e38/18e18.
Most people use the A class of the C class for sub-nets. I have not yet designed a network that needs an A class set of numbers. I also like to give the clients in each subnet plenty of room to expand, while still allowing them to have a reasonable subnet hierachy in place. Thus I tend to use the B class address numbers.
Take 172.16.x.x as the business network, it has a number of different locations or work groups, so I can use the 3rd octet to designate locations / work groups and then use the 4th octet for 254 pcs within that group. Thus all HQ units will be between 172.16.0.x and 172.16.9.x, gateway and system admin is 172.16.0.x, business admin is 172.16.1.x, sales 172.16.2.x etc - second facility is 172.16.10.x to 172.16.19.x, gateway and system admin is 172.16.10.x, business admin is 172.16.11.x etc.
Yes that means a lot of address go unused. But I once spent a nice two months reassigning sub-net addresses and adjusting routers and dns servers because the initial network only needed 20 clients in its largest sub-net with a total of 160 all up. It took 3 years for the business growth to trash the C class subnet that had been originally set up. Much of the time was spent travelling between facilities reprogramming the routers, dhcp servers and dns servers. Spent some time redseigning the system, then reprogrammed everything using both, got the new stuff running and went back around removing the old - all to ensure no problems with the day to day operation during the change over.
If you need more than this you can apply the same to the 10.x.x.x private address group. Much better to over allow for expansion than be too restrictive. And by using simple to remember digital octet groups you can readily tell what group and lcoation a particular IP address belongs to.
By applying the subnet at the last octet I can simplify the router instructions and make the subnet division easier to remember.
Take 172.16.x.x as the business network, it has a number of different locations or work groups, so I can use the 3rd octet to designate locations / work groups and then use the 4th octet for 254 pcs within that group. Thus all HQ units will be between 172.16.0.x and 172.16.9.x, gateway and system admin is 172.16.0.x, business admin is 172.16.1.x, sales 172.16.2.x etc - second facility is 172.16.10.x to 172.16.19.x, gateway and system admin is 172.16.10.x, business admin is 172.16.11.x etc.
Yes that means a lot of address go unused. But I once spent a nice two months reassigning sub-net addresses and adjusting routers and dns servers because the initial network only needed 20 clients in its largest sub-net with a total of 160 all up. It took 3 years for the business growth to trash the C class subnet that had been originally set up. Much of the time was spent travelling between facilities reprogramming the routers, dhcp servers and dns servers. Spent some time redseigning the system, then reprogrammed everything using both, got the new stuff running and went back around removing the old - all to ensure no problems with the day to day operation during the change over.
If you need more than this you can apply the same to the 10.x.x.x private address group. Much better to over allow for expansion than be too restrictive. And by using simple to remember digital octet groups you can readily tell what group and lcoation a particular IP address belongs to.
By applying the subnet at the last octet I can simplify the router instructions and make the subnet division easier to remember.
Thanks for that useful article, George! It's sad to acknowledge that so many IT professionals today are unschooled in binary math -- once the first step in a computer-related education -- but even those of us who can rattle off powers of two in their sleep can benefit from your time-saving tips.
Thanks again. This one's a keeper.
Thanks again. This one's a keeper.
http://www.lanarchitect.net/Designs/SubnetRuler/SubnetRuler.html
My animated ruler shows how it?s possible to map out a very large network. I might have to post a Visio with a vertical ruler as a useful download.
Oh, and please do note that I've issued a correction on Figure A and B so do download the newer version.
My animated ruler shows how it?s possible to map out a very large network. I might have to post a Visio with a vertical ruler as a useful download.
Oh, and please do note that I've issued a correction on Figure A and B so do download the newer version.
This is a very useful article on IP Subnetting and the first time I've ever seen anyone put all the information in one place. Great article.
George,
Excellent article - as another poster said, this one is a keeper. Even if one uses a subnet calculator program like SolarWinds it is still good to go back and review the basics.
The CCNA program I took at Sacramento City College drummed subnetting into our heads almost ad-nauseum, but I'm glad they did. I can almost (notice I said "almost") do subnetting in my head.
Also, thanks for making the article a downloadable PDF - good to keep on the laptop for reference.
Best Regards,
Bill Bowen
Excellent article - as another poster said, this one is a keeper. Even if one uses a subnet calculator program like SolarWinds it is still good to go back and review the basics.
The CCNA program I took at Sacramento City College drummed subnetting into our heads almost ad-nauseum, but I'm glad they did. I can almost (notice I said "almost") do subnetting in my head.
Also, thanks for making the article a downloadable PDF - good to keep on the laptop for reference.
Best Regards,
Bill Bowen
Sorry I had a mistake in Figure A and B. It was fixed on 6/3/2006. Please download the fixed version and discard the first version.
I haven't found the need for any special subnet calculators since I memorize numbers like 2, 4, 8, 16, 32 and 128, 192, 224, 240, 248, 252, 254, 255. Using the "AND" operator in Windows Calculator in decimal mode is also VERY useful and I never understood why that's usually not taught. I feel sorry for people when I see them doing binary conversions on tests.
The ruler allows you to allocate subnets without a calculator. You just make sure the edge tick marks are always taller than the tick marks in the middle and you know it?s a clean subnet.
I haven't found the need for any special subnet calculators since I memorize numbers like 2, 4, 8, 16, 32 and 128, 192, 224, 240, 248, 252, 254, 255. Using the "AND" operator in Windows Calculator in decimal mode is also VERY useful and I never understood why that's usually not taught. I feel sorry for people when I see them doing binary conversions on tests.
The ruler allows you to allocate subnets without a calculator. You just make sure the edge tick marks are always taller than the tick marks in the middle and you know it?s a clean subnet.
Can you tell me (or point me to) how you use the "AND" operator in Windows Calculator in decimal mode? How does this help in subnetting?
The procedure is clearly explained in this article. You simply need to read the section near the screen shot of the Windows calculator. Please read that section and if you still need some help, post another question here.
It seems straight forward from a (hardware high-level)hardware (software low-level)standpoint.
I guest if the SW guys have start looking at protocol layers from a opposite or upside down view.
Anyway thanks for the cheat-sheet
I guest if the SW guys have start looking at protocol layers from a opposite or upside down view.
Anyway thanks for the cheat-sheet
George, although I've been subnetting for years, I've found that using rulers cuts my time in half. Even for complex installs, I can quickly layout the entire network, move things around until I'm happy, and not have to check and recheck my math.
Thanks for the tip.
Thanks for the tip.
I issued a correction over the weekend and it was fixed on Monday morning. I had errors in Figure A and B where I should have had a 0 in the second octet. If you've downloaded something, please re-download it. Sorry for my mistake!
I also forgot to mention that I have an animated version of the ruler here:
http://www.lanarchitect.net/Designs/SubnetRuler/SubnetRuler.html
The animated ruler shows how it?s possible to map out a very large network.
I also forgot to mention that I have an animated version of the ruler here:
http://www.lanarchitect.net/Designs/SubnetRuler/SubnetRuler.html
The animated ruler shows how it?s possible to map out a very large network.
I issued a correction over the weekend and it was fixed on Monday morning. I had errors in Figure A and B where I should have had a 0 in the second octet. If you've downloaded something, please re-download it. Sorry for my mistake!
I also forgot to mention that I have an animated version of the ruler here:
http://www.lanarchitect.net/Designs/SubnetRuler/SubnetRuler.html
The animated ruler shows how it?s possible to map out a very large network.
I also forgot to mention that I have an animated version of the ruler here:
http://www.lanarchitect.net/Designs/SubnetRuler/SubnetRuler.html
The animated ruler shows how it?s possible to map out a very large network.
Now I understand what /21 and /24 means after an IP address
Um, you're referring to the DECIMAL form of subnet addresses (re: 255.255.255.0), it is *NOT* base 256, it is base 10. It is the decimal format of a binary number. If it was base 256 it would have two possible values, 0 and 1, 0 being 0 and 1 being 256.
It scares me that you're teaching other people subnetting :/
It scares me that you're teaching other people subnetting :/
Yes, a 4-digit base-256 number written with base-10 symbols and separated by periods. A 12 digit base-10 number would actually be 999.999.999.999 and last time I checked there is no such IP address. Even if we used Hex symbols like FF.FF.FF.FF (which is a valid way to write an IP address) to represent an IP address it would STILL be a 4-digit base-256.
The reason we use base-10 or base-16 symbols to represent a base-256 number is because no official symbols exist for base-256. But let's say that the symbol (+) had been chosen to represent the highest number in a base-256 system, then the largest IP address number would be (+).(+).(+).(+)
But all this is just arbitrary on how we use the period separator. An IP address could just as easily use 7 period separators for an 8-digit HEX number instead so the biggest IP address would look like "F.F.F.F.F.F.F.F". But instead we're using 3 separators making it "FF.FF.FF.FF" which makes it a 4-digit base-256 number.
If we were truly using a decimal system then IP addresses would run from 0 to 4294967296 though that would be extremely confusing.
I've personally have had programmers thank me that I'm the first to give the proper explaination that an IP address is a 4-digit base-256 number (written with base-10 symbols) and NOT a 12-digit base-10 number which would actually result in a maximum IP address of 999.999.999.999. This programmer never figured out why IP addresses stop at 255.255.255.255 and it finally made sense when I called it a base-256 number.
"It scares me that you're teaching other people subnetting :/"
You should to be careful about putting other people down when you clearly don't understand the math. I take a lot of pride in this particular article because it's used to teach IP subnetting in schools.
"If it was base 256 it would have two possible values, 0 and 1, 0 being 0 and 1 being 256."
YIKES!
Base-2 has 2 possible values from 0 to 1.
Base-10 has 10 possible values from 0 to 9.
Base-16 has 16 possible values from 0 to F.
Base-256 has 256 possible values from 0 to 255.
The reason I say 0 to 255 because there were no symbols created beyond base-16 so we're forced to use base-10 symbols to represent it.
The reason we use base-10 or base-16 symbols to represent a base-256 number is because no official symbols exist for base-256. But let's say that the symbol (+) had been chosen to represent the highest number in a base-256 system, then the largest IP address number would be (+).(+).(+).(+)
But all this is just arbitrary on how we use the period separator. An IP address could just as easily use 7 period separators for an 8-digit HEX number instead so the biggest IP address would look like "F.F.F.F.F.F.F.F". But instead we're using 3 separators making it "FF.FF.FF.FF" which makes it a 4-digit base-256 number.
If we were truly using a decimal system then IP addresses would run from 0 to 4294967296 though that would be extremely confusing.
I've personally have had programmers thank me that I'm the first to give the proper explaination that an IP address is a 4-digit base-256 number (written with base-10 symbols) and NOT a 12-digit base-10 number which would actually result in a maximum IP address of 999.999.999.999. This programmer never figured out why IP addresses stop at 255.255.255.255 and it finally made sense when I called it a base-256 number.
"It scares me that you're teaching other people subnetting :/"
You should to be careful about putting other people down when you clearly don't understand the math. I take a lot of pride in this particular article because it's used to teach IP subnetting in schools.
"If it was base 256 it would have two possible values, 0 and 1, 0 being 0 and 1 being 256."
YIKES!
Base-2 has 2 possible values from 0 to 1.
Base-10 has 10 possible values from 0 to 9.
Base-16 has 16 possible values from 0 to F.
Base-256 has 256 possible values from 0 to 255.
The reason I say 0 to 255 because there were no symbols created beyond base-16 so we're forced to use base-10 symbols to represent it.
This article has help me get out of the dark on this. But I'm still fuzzy on something. In looking over some test questions for an exam I saw a question with an IP of 192.168.0.100 that asks you to guess what subnet mask address it uses 255.255.255.0 or 255.255.240.0 with no other info given. The answer was 255.255.255.0 but I don't understand how they got this. I know the default subnet mask of a class C address is 255.255.255.0 but how do you know when you should use this or 240 etc etc
Thanks
qb
Thanks
qb
In general, any class C address is /24 or 255.255.255.0. Only supernetted class C address that are consolidated can be 255.255.240.0. 192.168.0.0 can actually have a mask of 255.255.0.0 if you wanted to. It's just that 255.255.255.0 is what's commonly used.
If that was a real question, it sucks. It's too vague and it gives multiple valid answers. You just have to pick the "best" answer.
If that was a real question, it sucks. It's too vague and it gives multiple valid answers. You just have to pick the "best" answer.
I have to admit when I first saw the base 256 reference, I was also confused by it but now understand what you are saying.
Could we also refer to this as modulo 256?
Could we also refer to this as modulo 256?
At first glance (and since this is the first thing I have glanced at since registering) I thought it was a worthy effort. I will take a closer look when I have time. Just curious if this is a site where one type-o will destroy a thread?
This was made so easy that if a person is supposed to know about the subnetting, he will definetly understand that.
Im doing Cisco ccna1 version 4.0 currently and we have just being doing chapter 6 on subnetting and this is far better at explaining than cisco was..
They have mistakes in thier lab books.. and that can throw a person right off track.. so thank you for clearing this up for me once and for sure..
They have mistakes in thier lab books.. and that can throw a person right off track.. so thank you for clearing this up for me once and for sure..
Remember my calculator shortcut where you don't worry about binary conversions. Every subnetting course I've every seen teaches you to do binary conversions and it's not needed in practice. The binary conversion is just there to teach you the low-level concept of subnetting.
How do i determine the subnet mask when i only got an IP range? (ex: 207.46.200.0-207.46.207.255)
By looking at the third octet it's 200 to 207 which means you have eight 3rd octet numbers. You need that mask where the 0s are 8 long so 255-8=247. But you need to include 255 which means you start at 248. 248 - 255 is exactly 8 long so your subnet mask for the third octet is 248.
Your full mask is 255.255.248.0. However, that doesn't mean that the desired range of 200-207 is a legitimate range so we must do a quick check. Fire up the windows calculator and type in 207, hit the AND button, type 248, and your result should be 200 which is the legitimate network ID and starting point for our subnet range.
248 in the third octet should be a /21 subnet mask. It would serve you well if you memorized the table of common subnet lengths and there's really not that many.
Your full mask is 255.255.248.0. However, that doesn't mean that the desired range of 200-207 is a legitimate range so we must do a quick check. Fire up the windows calculator and type in 207, hit the AND button, type 248, and your result should be 200 which is the legitimate network ID and starting point for our subnet range.
248 in the third octet should be a /21 subnet mask. It would serve you well if you memorized the table of common subnet lengths and there's really not that many.
This is quite a nice solution for subnetting and I hope a lot of people will find it useful
Thank YOU! My exercise book and tutors have left my brain totally messed up trying to get to grips with this subject.
Phil.
Phil.
Unfortunately I hear that too often. I knew it was a painful subject and the training material was always bad from what I've seen. That's why I wrote this article.
for me was when ANDing was explained (as an after thought....). I spent about an hour on the internet and subnetting made much more sense. Nowadays I have to work at it harder since I never use it. Thanks for this article, it was a great refresher, and I think the ruler will help tons with VLSM when next I need it. This PDF is going in my permanent collection. Once again, thanks.
i cant understand sub netting i want detail of it can any one give me
Guys the best on-line subnet calculator. http://www.gwebtools.com/ip-subnet-calculator
im sorry but i think this is more confuseing than what my teacher taught me you only showed class A addresses but it helped a little bit thank you for this article
Simple, very nice. Subnets have always been sort of a black magic type deal with me until I read this article.
After 45 days in class and reading I finally have a grasp on subnetting. Thanks.
its goog...i appreciated the way you expalin it...easy to understand
I hadn't even touched subnetting since my MCSE exams back in 2000. Your "IP Subnetting Made Easy" gave me a brief but effective review and helped me tackle a job I'd otherwise have spent 20 instead of 3 hours on.
Thank you!
Bob Lippold
Thank you!
Bob Lippold
Excellent reading and practice material for IT students.
Thanks George
Thanks George
Awesome article! Thank you, I will definitely be using this as a reference in the course of my studies.
How would you answer (and what is the math behind) this question:
Question: How many subnets and hosts per subnet can you get from the network 172.18.0.0 255.255.252.0?
Answer: 64 subnets and 1022 hosts
Question: How many subnets and hosts per subnet can you get from the network 172.18.0.0 255.255.252.0?
Answer: 64 subnets and 1022 hosts
What is the math behind the following question? Particularly I don;t understand how to calculate number of subnets other than 2^6=64 because 255.0.0.0 is 0 subnet bits and 255.255.252.0 is six subnet bits. Other than a chart how would I know this?
Question: How many subnets and hosts per subnet can you get from the network 172.18.0.0 255.255.252.0?
Answer: 64 subnets and 1022 hosts
Question: How many subnets and hosts per subnet can you get from the network 172.18.0.0 255.255.252.0?
Answer: 64 subnets and 1022 hosts
you get 1022 hosts by taking the number of 0s on the right in the subnet mask (when written in binary, as in 11111111.11111111.11111100.00000000), which is 10, and taking 2 to that power. 2^10 is 1024, but then you don't count the network id or broadcast address, so you get 1022. I'm not sure how to get that 64 subnet figure, though.
If you are an IT person supporting a small to medium business, they need a couple of public IP's to get out to the internet and the rest are private IP???s running behind a server running NAT. You need to assign each computer different IP's without buying them all public IP addresses. That???s where subnetting comes in, dissecting those private IP addresses for use on a private network.
IT WAS O.K BUT I STILL THINK THIER IS A SHOTER WAY TO DO THIS SUBNETTING THING REALLY
Here are some sites to learn and practice subnetting:
http://easysubnet.com/
http://subnettingquestions.com
http://easysubnet.com/
http://subnettingquestions.com
I am currently going to class at ITT Tech. No one ever explained subnetting quite as well as this article has. I have printed this article off and handed it to many people. This is one of those articles that makes the light click on. The trick with the calculator in Windows works wonders! Thanks a ton!
The IP addresses on the lower labels are different from the IP addresses in the green areas. For example, where 10.0.24.0 is in the lower legend, the green area is marked 10.24.0.0. Are they wrong or did I completely misunderstand this graphic?
Hands down the most simple explanation to understand on the subject I have ever seen.
AWESOME Article! I was totally dreading taking certification tests until now. Thank You. I have read the article over a dozen times. The only improvement I could recommend is this. Explain that subnetting is only for Private IP addressing. I had that AHA! moment driving into work 1 morning. Great article!
George
Your article really helped me (I've just been tasked with changing masks to go from 512 to 1024 host addresses) - I especially liked bit about using AND on Windows Calc
Thanks muchly - just the right length and I liked the graphics - very well written
Good on ya!
Simon Trangmar - Adelaide Australia
Your article really helped me (I've just been tasked with changing masks to go from 512 to 1024 host addresses) - I especially liked bit about using AND on Windows Calc
Thanks muchly - just the right length and I liked the graphics - very well written
Good on ya!
Simon Trangmar - Adelaide Australia
Hello George.
Thanks you very much for this useful article,I'm new to subnetting and you have made things much easier to understand. However I been trying to use your system to calculate the number of subnet bits and I am stuck I just can't get the answer. Could you please help. The question is as follows...
How many subnets and hosts per subnet can you get from the network 172.29.0.0 255.255.254.0?
Answer: 128 subnets and 510 hosts
I understand that 255.255.254.0 = (1+8)=9 = 2/9 = 512-2 = 510 hosts
However how do I get the number of subnets?
Any help would be much appreciated.
Thanks you very much for this useful article,I'm new to subnetting and you have made things much easier to understand. However I been trying to use your system to calculate the number of subnet bits and I am stuck I just can't get the answer. Could you please help. The question is as follows...
How many subnets and hosts per subnet can you get from the network 172.29.0.0 255.255.254.0?
Answer: 128 subnets and 510 hosts
I understand that 255.255.254.0 = (1+8)=9 = 2/9 = 512-2 = 510 hosts
However how do I get the number of subnets?
Any help would be much appreciated.
I realize this is an old post but I'll do my best because this is a good question.
"How many subnets and hosts per subnet can you get from the network 172.29.0.0 255.255.254.0?
Answer: 128 subnets and 510 hosts
I understand that 255.255.254.0 = (1+8)=9 = 2/9 = 512-2 = 510 hosts
However how do I get the number of subnets?"
if a mask of 255.255.254.0 gives you 512 ip's then your subnets are in increments of 2 (think 256x2) in the third octet ie 172.29.0.0-172.29.2.255 then 172.29.3.0-172.29.4.255 ect. each with a mask of 255.255.254.0 you will have 128 of these subnets to cover the 256 possibilities from 0-255 there are many other ways to do the math but I find this one to be the quickest for me.
"How many subnets and hosts per subnet can you get from the network 172.29.0.0 255.255.254.0?
Answer: 128 subnets and 510 hosts
I understand that 255.255.254.0 = (1+8)=9 = 2/9 = 512-2 = 510 hosts
However how do I get the number of subnets?"
if a mask of 255.255.254.0 gives you 512 ip's then your subnets are in increments of 2 (think 256x2) in the third octet ie 172.29.0.0-172.29.2.255 then 172.29.3.0-172.29.4.255 ect. each with a mask of 255.255.254.0 you will have 128 of these subnets to cover the 256 possibilities from 0-255 there are many other ways to do the math but I find this one to be the quickest for me.
You do not need to know the number of hosts or ips to find the answer as you can also look at it only from the third octet (256-254=2) which makes the same above true x.x.0.0 - x.x.2.255 ect. and since 256 divided by increments of 2 is 128 you could answer the question if it only asked for maximum number of subnets with that network and mask
Its makes a lot more sense now.
Sorry for the delay
Sorry for the delay
"I'll never understand why this isn't explained to students, because it makes mask calculations a lot easier."
The reason this isn't explained is because when it comes test time, you're not going to be allowed to use a calculator. Which is blasphemy, really.
The reason this isn't explained is because when it comes test time, you're not going to be allowed to use a calculator. Which is blasphemy, really.
hey everyone-
i'd just like to contribute to the conversation with this video tutorial on IP addressing.
http://www.bosscbt.tv/uncategorized/intro-to-ip-addressing-part-i/
enjoy & good luck!
i'd just like to contribute to the conversation with this video tutorial on IP addressing.
http://www.bosscbt.tv/uncategorized/intro-to-ip-addressing-part-i/
enjoy & good luck!
Hey I am a student and we are starting to learn about this now I was having a bit of trouble understanding it after reading this I know understand it, thanks for the great guide
I was having a bit of trouble understanding it after reading this I know understand it, thanks for the great guide 
OK, it makes sense... but something doesn' t add up. When I take and attempt to apply what you just taught to the 10.0.0.0 / 8, I figure that the subnet is 255.255.255.0 and that the IP range has 256 hosts and resides between 10.0.0.0 and 10.0.0.255. So, I figured maybe you made a mistake and it was supposed to be 10.0.0.0 / 24; but EVERYTHING I read agrees with you: 10.0.0.0 / 8 and resides between 10.0.0.0 and 10.255.255.255--- which doesn't work out with what you just taught... so I'm confused again...
oof... looking in the wrong place, I was looking at the subnet length, not the mask length... srry... lol
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