topic Re: Netmask calculation in Operating System - HP-UX

Netmask calculation

yc_2 — Fri, 22 Jul 2005 02:06:15 GMT

Hi,

(1) How to calculate netmask of an IP address?
(2) Is there any free software that perform the function that feed in IP address and output its netmask?

Thanks in advance.

Re: Netmask calculation

Warren_9 — Fri, 22 Jul 2005 02:14:42 GMT

try this

http://logi.cc/nw/NetBitCalc.html

Re: Netmask calculation

Michael Schulte zur Sur — Fri, 22 Jul 2005 14:01:17 GMT

Hi,

There are several classes of ip addresses.
The class is determined by the first byte.
Class A = 1-127 netmask 255.0.0.0
Class B = 128-191 netmask 255.255.0.0
Class C = 192-223 netmask 255.255.255.0
..
However you can not calculate the netmask from the ip address. The netmask divides the ip address into the net portion and the host portion. You can divide the ip range still into subnets. So, there is no fix relationship between ip and netmask.

greetings,

Michael

Re: Netmask calculation

Tim Nelson — Fri, 22 Jul 2005 15:52:50 GMT

Try this online subnet netmask calculator

http://www.subnet-calculator.com/