Hi, i can subnet pretty good, but when it comes to finding subnets ID in large subnets it takes me a while, so if you had 10.0.0.0/12 that"s 4096 subnets, and the question was --what is the 1010th subnet ID and range of IP addresses, what would be the fastest way. thanks MIKE
P.S. division and mult. got to be in this because we a turning more then once in smae octer, posted on cisco learning only got on answer and did not land on a subnet ID number, so i am hoping someone we see this a show me the way. Thanks mic
Re: Finding subnet ID in large claa a network
7 years 6 months ago #38387
Sorry Karma about that, It was early in the morning I had a typo, I meant /20. I think I got it but, just in case can you explain once more with the /20 With the 1010th subnet ID, I just what to make sure I got this down and practice it more, Thank you so much for your help , lot of people don't know this, thanks again. Mic! P.S. I see it in the small networks with the bits in action or only with using one octet to the right , but when it comes to using two octets like in /20 or more having hard time, your second example picks out the last one then moves to lower one I don't see it in the bits, there is 16 bits that's 65536, so as you can see I am missing something , as i said I don't see it in the bits, please explain, I really need to understand this, Thanks for third time. Mic , Karma
Re: Finding subnet ID in large claa a network
7 years 6 months ago #38390
Thank you so much Nevins, i got it, Just a FAST reveiw --first -1 off subnet ID you are looking for, then ---just start with bits from right to left with 1-2-4-8-16-32-64-128-256-512 and so on if bigger subnet ID, add the proper bits together till you get your subnet ID number, then put period (dot) in proper place --every 8 bits and that"s your subnet ID will be. RIGHT---thank you so much for the help i went to 4 sites and could not get what you have told me. Love ya network man.Thanks again Mic
Re: Finding subnet ID in large claa a network
7 years 6 months ago #38392
The first subnet starts at 0 and each successive subnet is 1 bit greater.
The number of subnets is limited by the number of subnetting bits.
(this can be calculated with the formula 2^S where s is the number of subnetting bits)
If you have 4 bits for subnetting the subnet bits look like: