This is a text-only version of the following page on https://raymii.org: --- Title : CIDR Cheatsheet Author : Frank Shafer Date : 11-12-2012 URL : https://raymii.org/s/software/CIDR-Cheatsheet.html Format : Markdown/HTML ---

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CIDR Total number Network Description: Notation: of addresses: Mask: -------------------------------------------------------------- /0 4,294,967,296 0.0.0.0 Every Address /1 2,147,483,648 128.0.0.0 128 /8 nets /2 1,073,741,824 192.0.0.0 64 /8 nets /3 536,870,912 224.0.0.0 32 /8 nets /4 268,435,456 240.0.0.0 16 /8 nets /5 134,217,728 248.0.0.0 8 /8 nets /6 67,108,864 252.0.0.0 4 /8 nets /7 33,554,432 254.0.0.0 2 /8 nets /8 16,777,214 255.0.0.0 1 /8 net (Class A) -------------------------------------------------------------- /9 8,388,608 255.128.0.0 128 /16 nets /10 4,194,304 255.192.0.0 64 /16 nets /11 2,097,152 255.224.0.0 32 /16 nets /12 1,048,576 255.240.0.0 16 /16 nets /13 524,288 255.248.0.0 8 /16 nets /14 262,144 255.252.0.0 4 /16 nets /15 131.072 255.254.0.0 2 /16 nets /16 65,536 255.255.0.0 1 /16 (Class B) -------------------------------------------------------------- /17 32,768 255.255.128.0 128 /24 nets /19 16,384 255.255.192.0 64 /24 nets /19 8,192 255.255.224.0 32 /24 nets /20 4,096 255.255.240.0 16 /24 nets /21 2,048 255.255.248.0 8 /24 nets /22 1,024 255.255.252.0 4 /24 nets /23 512 255.255.254.0 2 /24 nets /24 256 255.255.255.0 1 /24 (Class C) -------------------------------------------------------------- /25 128 255.255.255.128 Half of a /24 /26 64 255.255.255.192 Fourth of a /24 /27 32 255.255.255.224 Eighth of a /24 /28 16 255.255.255.240 1/16th of a /24 /29 8 255.255.255.248 5 Usable addresses /30 4 255.255.255.252 1 Usable address /31 2 255.255.255.254 Unusable /32 1 255.255.255.255 Single host -------------------------------------------------------------- Reserved Space: 0.0.0.0/8 127.0.0.0/8 192.0.2.0/24 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 169.254.0.0/16 Via: [1]: https://www.digitalocean.com/?refcode=7435ae6b8212 --- License: All the text on this website is free as in freedom unless stated otherwise. This means you can use it in any way you want, you can copy it, change it the way you like and republish it, as long as you release the (modified) content under the same license to give others the same freedoms you've got and place my name and a link to this site with the article as source. This site uses Google Analytics for statistics and Google Adwords for advertisements. You are tracked and Google knows everything about you. Use an adblocker like ublock-origin if you don't want it. All the code on this website is licensed under the GNU GPL v3 license unless already licensed under a license which does not allows this form of licensing or if another license is stated on that page / in that software: This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . Just to be clear, the information on this website is for meant for educational purposes and you use it at your own risk. I do not take responsibility if you screw something up. Use common sense, do not 'rm -rf /' as root for example. If you have any questions then do not hesitate to contact me. See https://raymii.org/s/static/About.html for details.