can someone please help me out? i am having difficulty with this mask.can i subnet a class A address with 23 bits of subnetting? e.g.
10.20.0.0/23 is given to me and i need to subnet it to accomodate one subnet with 200 hosts, one subnet with 150 hosts, one subnet with 70 hosts and two subnets with 50 hosts each... i know i can use
10.20.0.0/24 to accomodate the first subnet with 200 hosts, what about the rest?
A /23 has only 508 hosts total (255 * 2 = 510, minus network/broadcast addresses). With only a single /23, you can't service 520 hosts as you are asking. Second, and because networks can only be split into networks of specific sizes, you can't create networks for exactly that many hosts. You could do a /24 for the 200 requirement, or perhaps a /
25, a /26, and a /30, which would give you 128 + 64 + 16. The first option would 'waste' 54 addresses, and the latter aren't going to be in the same broadcast domain. In short, get more than a /23, and try to consolidate your requirements or figure out more appropriate IP architecture. There is nothing wrong with a /23 or /22 network with all hosts in the same broadcast domain, especially since most modern networks are gig speed or faster......
I'm sorry, I was typing as a /15 above....not /23......same thing applies but I was 1 octet off............
So you can use any 10.20.x.x/23? I guess I didn't pick up on that before. Why can't you segment beyond /23 as proposed? You would easily meet your requirements by splitting up the /23 as I had suggested (slight modifications to meet your exact requirements, and using a small portion of the second /23 (10.20.2.0) for the last 120.