[plug] subnetworking help

[Anthony J. Breeds-Taurima]

On Thu, 20 Dec 2001, BaRT wrote:

> Hi,
> 
> I need to split a C class into some subnets a /25 /27 and a /29. How do I
> work out the netmasks Bcast, and how many hosts will be in each subnet. Iv
> had a look at the IP-subnetworking howto and I still dont understand.

Assuming you know about binary maths including AND, OR and NOT.  Here a
summarized tute.

A /nn represents home many consecutive bits there are in your subnetmask
ie
/22 = 255.255.252.0
/24 = 255.255.255.0
/25 = 255.255.255.128
etc etc