Re: First draft of the European Template for IP number requests
- Date: Thu, 10 Dec 92 11:08:03 +0100
"Peter Koch" pmk@localhost writes:
*
* Marten.Terpstra@localhost writes:
*
* > Havard.Eidnes@localhost writes:
*
* [...]
* If you have the need for two large subnets, you have to use a mask of 2:6
* (see below). This is bad, we have in some cases seen subnets of size 50-70
* and
* then had to assign one C address for each of them.
*
* If you actually use subnetting 3:5, you have 2^3-2=6 subnets with
* 2^5-2=30 hosts each. You have a maximum of 180 hosts here (router(s) not ta
* ken
* into account), an unsubnetted network would offer 254, so this is about 71
* %.
*
* Looking at all possible subnet masks, you get:
*
* subnet mask | # subnets | # hosts/subnet | total # hosts | usage
* -------------+------------+----------------+---------------+------
* 1:7 | not allowed| | |
* 2:6 | 2 | 62 | 124 | 49 %
* 3:5 | 6 | 30 | 180 | 71 %
* 4:4 | 14 | 14 | 196 | 77 %
* 5:3 | 30 | 6 | 180 | 71 %
* 6:2 | 62 | 2 | 124 | 49 %
* 7:1 | not allowed| | |
*
* Percentage is nothing to worry about too much.
* More address space would be wasted if you would assign a full class C net
* for every subnet the requestor operates.
Sorry about my fantastic calculations. You are of course right. I'll make
sure I get some more coffee next time ;-)
* Peter
-Marten
