How to calculate a TCPIP IPv4 subnet mask

[bomsbravo]

great it helped a lot.thank u.

[icl0udn3t]

thank you



[mohsin213jc]

wow you made this easy. thanks

[MattD00]

Thank you for the explanation. I never quite got the grasp of working out subnet masks before.

[vszabad]

omg my teacher explained this to us in a different languege i think. thankyou so much now i understand it.!!! :) (ihave a ccna exam next week, wish my luck :3)

[mymusicfunforbordom]

Thanks a lot this was really helpful

[mymusicfunforbordom]

Thanks a lot this was really helpful

[ProCartelMarketing]

This lady explained subnetting the way I needed to hear it. Awesome job madam!

[richiehughes1992]

Finally I found this video which has really helped me understand subnetting! Thank you!

[sonalv9891]

Why Would You Dislike This Video LOL .. 4 Dislikes? 4 Retarded People =\

[hurson1981]

Thank you! :)

Studying Computing at university and going to be having my exam in January, and your video helped clear a lot of things up.

[ibjazzy]

Thank you so much for your video, I've been trying to get this for a while, and your video was simple and to the point. Thanks again.

[error503]

Thank you lady. You are better than a lot of these assholes who make no sense.

[ImajouI]

You explain very clear, Thank you very much helped me a lot

[bicesz]

Sorry but exercise at the end of the tutorial USUABLE RANGE WHAT happend with the interval 220.56.10.1- 220.56.10.31 ??????????????????

[2arprodlim3]

@bicesz

It all makes more sense if you look at the IPv4 addresses in binary. If you borrow 3 bits from the host side to add more networks you are technically creating 8 new networks. However, the first and last address group have to be dropped (unless you use some Cisco equipment) because the first group has all the bits off in the host portions of the addresses and the last group has all the bits on in the host portions of the addresses. This requires binary adding to see and I've run out of

[BishopOsa]

Goodjob. I preffered your explanation.

[2arprodlim3]

@BishopOsa

Thanks. I'm glad you liked this. I learned subnetting a while back when taking a Microsoft course and if it hadn't been for an O'Reilly book I would have never passed the cert. Yeas later a friend of mine showed me this process and I just don't understand why anyone would want to use some of the longer and harder versions I've seen.

[BishopOsa]

@2arprodlim3

thanks for your response. Do you have more videos on cisco?

[meeputube]

Thank you!

[godsangellucifer]

you should work for Brazzers!

[2arprodlim3]

@godsangellucifer

Hadn't ever heard of them. This video was originally posed as a "job application" for a company that wanted on-line instructors. Never did hear back from that place but this little video seems to have helped a few folks and that's fine with me. I don't think Brazzers is for me.

[mysteriously01]

Great video

[wstinson403]

A very good tutorial. Thanks

[orbital92hotmail]

would anyone fuck her for a pass in the CCNA? I would.

[shualaz]

helped me alot better than other videos!! thanks

[theoriginalfatdonkey]

hey 2 to the third equals eight not six!!!!

[IvoSimeonov]

@theoriginalfatdonkey Yes but 2 to the third MINUS 2 does equal 6, read the whole thing before you write

[theoriginalfatdonkey]

@IvoSimeonov in networking u use 2n-1 not 2n-2.....u need to refresh your memory. ;) subnet zero

[2arprodlim3]

@theoriginalfatdonkey

Very true. However, there are some reserved addresses in IPv4 including any with all zeros in the host portion of the address (have to put stuff in binary to really see this) which denotes the network address and any with all bits on (binary 1's) in the host portion of the address which denotes a broadcast. That is why the formula is 2(n) -2.

[carolm62]

I appreciate this video! I can sorta tell that there is a great explantion in there, the best I've seen so far, but it is delivered too fast to process. Maybe you could do one in slow motion...? :-)

[har183]

great video ,great work.please keep helping us with more videos.

[Mrdanielmartins91]

Thanks Ma'am,

Thumbs up from me!

[MrDIegoValerio]

was looking for the best explanation and this is it

[badinformer]

but why u choose 32bits in the host?

[2arprodlim3]

@badinformer

The 32nd bit (or third one from the left that we borrow) is what Cisco calls the increment bit. The value of this bit (whichever one you need to borrow depending upon how many networks you need to create) is used to determine the range of network/host addresses for each of the networks. Maybe I need to post another example ...

[MrAravind35]

MADAM VERY VERY THANK U FOR UR EFFORT TO TEACH SUBNETTING IN A SIMPLE WAY. YOU HAVE TAUGHT IT JUST IN 6 MINUTES 17 MINUTES. WHAT MY TEACHER COULD NOT DO IN MONTHS.STILL IAM NOT SURE WHAT HE TAUGHT ME. THEY ONLY TAUGHT FOR MONEY .

[2arprodlim3]

@MrAravind35

I've been stuck in some classes like that. I don't mean to pick on Microsoft, but their way of explaining subnetting is undecipherable to most people.

Glad you liked this. Thanks for your kind words.

[RogueScout22]

Great video. This really helped me out

[RogueScout22]

Great video this really helped me out

[anuthehigh]

What if you have an Ip of 156.60.x.x and you have 5 bits,6 subnets,9 host?

[2arprodlim3]

@anuthehigh

If you start with a IPv4 Class B address then you are borrowing from the third octet. Your increment is in the third octet. First address usable address range would be 156.60.32.1 through 156.60.63.254

[blackstorm5000]

Thanks alot , your video helped me a tone, I hope you upload more videos soon

Keep up the great work

[2arprodlim3]

@blackstorm5000

Actually I have some stuff I want to do but my video guy is working on the sequel to the Adventures of IT Super Heros and I have to wait till that is done ..

[MrNicksta1011]

Thanks alot helped me out, found this so confusing up till now

[aeomus26]

Thank you!!

[scheme007]

Excellent tutorial. She explained it with such grace that I'm confident that after some practice, i'll master this. Thanks!

[Markohoppis]

You must count over three bits from the left, not from the right or just randomly choose a spot?

Didn't know that the eight 1's represented those numbers; i.e. 128, 64, etc...I don't see why 32 holds so much importance and why use it to calculate range of network addresses. Seems so arbitrary.

Phew, hopefully I can find a competent book to explain more of the basics, there are so many bad vague esoteric books on subjects like these.

[2arprodlim3]

@Markohoppis

Going from decimal to binary is a bit strange at first. Maybe I should make a video about that. Decimal 1 and binary 1 are the same. Decimal 2 is binary 10. Decimal 3 is binary 11. Decimal 4 is binary 100 ...

[chaincommon]

Find IP subnet address of 168.120.9.230, given subnet mask 255.255.255.240

What is this answer ?

[Thetrutv]

Thanks, hope you make more videos

[jmsa007]

the formula 2^n - 2 is not correct! That formula gives the maximum number of hosts with n bits in the host side. If you want 5 networks, the formula is just 2^n >= 5. That still gives n = 3. With n =3 we have 8 networks!

[2arprodlim3]

@jmsa007

I'm giving the information based on the certification test format. In reality you are correct, especially with the right Cisco equipment. If you are preparing for a CompTIA exam, you would need to use my formula.

[paq7512]

@2arprodlim3 This is a little confusing for people that are learning, since 2^n-2 is for calculating hosts not networks. jmsa007 is correct.

[fochsi]

@jmsa007 the formula is correct, 2^x-2 subnets and s^x-2 hosts.

[thrillcode]

@jmsa007 That's what i thought?!

[mortal486]

You're simply amazing. Thanks for the post.

[lredmikel]

Thanks you!

This for a great video!

[greeppl]

thanks

[blade004]

What do you mean exactly when you say "all bits ON" and "all bits OFF"?

BTW - Excellent video, although it did take multiple views to understand it properly ;), except for the bits OFF and ON? bits off and on i represent in binary as 0 being off and 1 being on.

[2arprodlim3]

@blade004 All bits off is a network address (in binary) and all bits on is a broadcast address (in binary). You can't use those for a host address.

[binargs]

well there is one problem with this video, in the ccna exam they don't necessary ask you to take off the zero subnet and boardcast subnet. it all depends on what are the given circumstances are. if nothing is mentioned, by default you are allowed to use them. but if rip v.1 is used or SLAM is mentioned, or "no ip zero subnet" command is found, then you do need to take off the 2 subnets from total.

[2arprodlim3]

@binargs Yea, it's kind of hard to create something that works for all certs and Cisco has been changing their stuff because of the new equipment they have.

[argenis365]

thanks!