====== Networking - Subnet Masks ======

[[Networking:Subnet Masks:Introduction to IP Addresses and Subnetting|Introduction to IP Addresses and Subnetting]]

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^ ^Addresses^Hosts^Netmask^Amount of a Class C^
|/30|4|2|255.255.255.252|1/64|
|/29|8|6|255.255.255.248|1/32|
|/28|16|14|255.255.255.240|1/16|
|/27|32|30|255.255.255.224|1/8|
|/26|64|62|255.255.255.192|1/4|
|/25|128|126|255.255.255.128|1/2|
|/24|256|254|255.255.255.0|1|
|/23|512|510|255.255.254.0|2|
|/22|1024|1022|255.255.252.0|4|
|/21|2048|2046|255.255.248.0|8|
|/20|4096|4094|255.255.240.0|16|
|/19|8192|8190|255.255.224.0|32|
|/18|16384|16382|255.255.192.0|64|
|/17|32768|32766|255.255.128.0|128|
|/16|65536|65534|255.255.0.0|256|

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===== Guide to sub-class C blocks =====

^/25^2 Subnets^126 Hosts/Subnet^
^Network #^IP Range^Broadcast^
|.0|.1-.126|.127|
|.128|.129-.254|.255|

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^/26^4 Subnets^62 Hosts/Subnet^
^Network #^IP Range^Broadcast^
|.0|.1-.62|.63|
|.64|.65-.126|.127|
|.128|.129-.190|.191|
|.192|.193-.254|.255|

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^/27^8 Subnets^30 Hosts/Subnet^
^Network #^IP Range^Broadcast^
|.0|.1-.30|.31|
|.32|.33-.62|.63|
|.64|.65-.94|.95|
|.96|.97-.126|.127|
|.128|.129-.158|.159|
|.160|.161-.190|.191|
|.192|.193-.222|.223|
|.224|.225-.254|.255|

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^/28^16 Subnets^14 Hosts/Subnet^
^Network #^IP Range^Broadcast^
|.0|.1-.14|.15|
|.16|.17-.30|.31|
|.32|.33-.46|.47|
|.48|.49-.62|.63|
|.64|.65-.78|.79|
|.80|.81-.94|.95|
|.96|.97-.110|.111|
|.112|.113-.126|.127|
|.128|.129-.142|.143|
|.144|.145-.158|.159|
|.160|.161-.174|.175|
|.176|.177-.190|.191|
|.192|.193-.206|.207|
|.208|.209-.222|.223|
|.224|.225-.238|.239|
|.240|.241-.254|.255|

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^/29^32 Subnets^6 Hosts/Subnet^
^Network #^IP Range^Broadcast^
|.0|.1-.6|.7|
|.8|.9-.14|.15|
|.16|.17-.22|.23|
|.24|.25-.30|.31|
|.32|.33-.38|.39|
|.40|.41-.46|.47|
|.48|.49-.54|.55|
|.56|.57-.62|.63|
|.64|.65-.70|.71|
|.72|.73-.78|.79|
|.80|.81-.86|.87|
|.88|.89-.94|.95|
|.96|.97-.102|.103|
|.104|.105-.110|.111|
|.112|.113-.118|.119|
|.120|.121-.126|.127|
|.128|.129-.134|.135|
|.136|.137-.142|.143|
|.144|.145-.150|.151|
|.152|.153-.158|.159|
|.160|.161-.166|.167|
|.168|.169-.174|.175|
|.176|.177-.182|.183|
|.184|.185-.190|.191|
|.192|.193-.198|.199|
|.200|.201-.206|.207|
|.208|.209-.214|.215|
|.216|.217-.222|.223|
|.224|.225-.230|.231|
|.232|.233-.238|.239|
|.240|.241-.246|.247|
|.248|.249-.254|.255|

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^/30^64 Subnets^2 Hosts/Subnet^
^Network #^IP Range^Broadcast^
|.0|.1-.2|.3|
|.4|.5-.6|.7|
|.8|.9-.10|.11|
|.12|.13-.14|.15|
|.16|.17-.18|.19|
|.20|.21-.22|.23|
|.24|.25-.26|.27|
|.28|.29-.30|.31|
|.32|.33-.34|.35|
|.36|.37-.38|.39|
|.40|.41-.42|.43|
|.44|.45-.46|.47|
|.48|.49-.50|.51|
|.52|.53-.54|.55|
|.56|.57-.58|.59|
|.60|.61-.62|.63|
|.64|.65-.66|.67|
|.68|.69-.70|.71|
|.72|.73-.74|.75|
|.76|.77-.78|.79|
|.80|.81-.82|.83|
|.84|.85-.86|.87|
|.88|.89-.90|.91|
|.92|.93-.94|.95|
|.96|.97-.98|.99|
|.100|.101-.102|.103|
|.104|.105-.106|.107|
|.108|.109-.110|.111|
|.112|.113-.114|.115|
|.116|.117-.118|.119|
|.120|.121-.122|.123|
|.124|.125-.126|.127|
|.128|.129-.130|.131|
|.132|.133-.134|.135|
|.136|.137-.138|.139|
|.140|.141-.142|.143|
|.144|.145-.146|.147|
|.148|.149-.150|.151|
|.152|.153-.154|.155|
|.156|.157-.158|.159|
|.160|.161-.162|.163|
|.164|.165-.166|.167|
|.168|.169-.170|.171|
|.172|.173-.174|.175|
|.176|.177-.178|.179|
|.180|.181-.182|.183|
|.184|.185-.186|.187|
|.188|.189-.190|.191|
|.192|.193-.194|.195|
|.196|.197-.198|.199|
|.200|.201-.202|.203|
|.204|.205-.206|.207|
|.208|.209-.210|.211|
|.212|.213-.214|.215|
|.216|.217-.218|.219|
|.220|.221-.222|.223|
|.224|.225-.226|.227|
|.228|.229-.230|.231|
|.232|.233-.234|.235|
|.236|.237-.238|.239|
|.240|.241-.242|.243|
|.244|.245-.246|.247|
|.248|.249-.250|.251|
|.252|.253-.254|.255|


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===== References =====

http://www.ietf.org/rfc/rfc1878.txt