Sponsored Content
Full Discussion: Subnetting
Special Forums IP Networking Subnetting Post 302993570 by drysdalk on Saturday 11th of March 2017 07:41:05 AM
Old 03-11-2017
Hi,

Firstly, from just looking at a single IP, you can't tell how large the network it's a part of is. You need to know the netmask. So for example, if I had an IP of 192.168.1.10, that doesn't tell you anything at all about how large or small the network I'm a part of is.

But if I tell you the netmask - e.g. 192.168.1.10/24 or 192.168.1.10/255.255.255.0 - then you know it's part of a network of 256 addresses, running from 192.168.1.0 to 192.168.1.255.

If on the other hand I'd told you the netmask was 192.168.1.10/25 or 192.168.1.10/255.255.255.128 - then you'd know it was part of a network of 128 addresses going from 192.168.1.0 to 192.168.1.127.

And again, in every network, the very first address and the very last address are not usable for hosts, as they are reserved for other purposes.

You can also get plenty of other netmasks than the old simple Class A, B, C notation tells you. For instance I could just have easily told you my netmask was 192.168.1.10/28, in which case you'd then be able to calculate that the network I was a part of runs from 192.168.1.0 to 192.168.1.15, and conists of 16 IP addresses.

So just from looking at an IP you can't tell anything about the size of the network. And these days, there are far more netmasks and subnet sizes that are far more common than the old Class A/B/C notation.
This User Gave Thanks to drysdalk For This Post:
 

3 More Discussions You Might Find Interesting

1. IP Networking

Subnetting

We have subnetted our Internal Network. We used an I.P. range of 172.16.16.0-254, 172.16.17.0-254, 172.16.18.0-254, 172.16.19.0-254 and mask 255.255.252.0. We created a subnet range of 172.16.10.0-254 and maske 255.255.255.0. Our routers are configure to route to approprate network. We are able... (2 Replies)
Discussion started by: cassy
2 Replies

2. IP Networking

Subnetting in 11 steps

As seen on Digg.com, here is my ip addressing article in full... Original Subnetting in 11 Steps article Subnetting in 11 Steps There are a few things that you will need to know first. I personally use 11 rules that I learned from Mike Vana. Below you will find the 11 rules as well as... (1 Reply)
Discussion started by: jking2100
1 Replies

3. IP Networking

Subnetting

Guys, Anyone could help me understand subnetting. I know a bit in networking but there are things that I don't get them easily. Thank You in advance. (1 Reply)
Discussion started by: etcpasswd
1 Replies
PRIPS(1)						    BSD General Commands Manual 						  PRIPS(1)

NAME
prips -- print the IP addresses in a given range SYNOPSIS
prips [-c] [-d delim] [-e exclude] [-f format] [-i incr] start end prips [-c] [-d delim] [-e exclude] [-f format] [-i incr] CIDR-block prips -h DESCRIPTION
The prips tool can be used to print all of the IP addresses in a given range. It can enhance tools that only work on one host at a time, e.g. whois(1). The prips tool accepts the following command-line options: -c Print the range in CIDR notation. -d delim Set the delimiter to the character with ASCII code delim where 0 <= delim <= 255. -e <x.x.x,x.x> Exclude ranges from the output. -f format Set the format of addresses (hex, dec, or dot). -h Show summary of options. -i incr Set the increment to 'x'. ENVIRONMENT
The prips tool's operation is not influenced by any environment variables. FILES
The prips tool's operation is not influenced by any files. EXAMPLES
Display all the addresses in a reserved subnet: prips 192.168.32.0 192.168.32.255 The same, using CIDR notation: prips 192.168.32/24 Display only the usable addresses in a class A reserved subnet using a space instead of a newline for a delimiter: prips -d 32 10.0.0.1 10.255.255.255 Display every fourth address in a weird block: prips -i 4 192.168.32.7 192.168.33.5 Determine the smallest CIDR block containing two addresses: prips -c 192.168.32.5 192.168.32.11 DIAGNOSTICS
The prips utility exits 0 on success, and >0 if an error occurs. SEE ALSO
ipsc(1), gipsc(1) STANDARDS
No standards were harmed in the writing of the prips tool. HISTORY
The prips tool was originally written by Daniel Kelly and later adopted by Peter Pentchev. This manual page was originally written by Juan Alvarez for the Debian GNU/Linux system and later added to the prips distribution and converted to mdoc format by Peter Pentchev. AUTHORS
Daniel Kelly <dan@vertekcorp.com> Juan Alvarez <jalvarez@fluidsignal.com> Peter Pentchev <roam@ringlet.net> BUGS
Please report any bugs in the prips tool to its current maintainer, Peter Pentchev. BSD
March 1, 2011 BSD
All times are GMT -4. The time now is 01:46 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy