Practice Exams for Windows

Practice Exams for Windows

Thursday, 20 November 2014

My Subnet Calculator


Subnet Calculator
128
64
32
16
8
4
2
1
Known IP
 
 
 
 
 
 
 
 
Subnet Mask
 
 
 
 
 
 
 
 
Subnet Address (AND)
 
 
 
 
 
 
 
 
Invert Mask
 
 
 
 
 
 
 
 
Broadcast Address (OR)
 
 
 
 
 
 
 
 

Instructions:
  1. Enter in the Known IP and subnet mask (only the octet that is not 255 or 0)
  2. Perform an AND operation
  3. Invert the Mask 
  4. Perform an OR operation 
Alternative method
Subnetting from a single host back:
/32 255.255.255.255 = 1 host (single host)

/31 255.255.255.254 = 2 hosts (2- 2 = 0 none useable)

/30 255.255.255.252 = 4 hosts (4 - 2 = 2 usable)

/29 255.255.255.248 = 8 hosts (8 - 2 = 6 usable)

/28 255.255.255.240 = 16 hosts (16 -2 = 14 usable and so on…)

/27 255.255.255.224 = 32 hosts

/26 255.255.255.192 = 64 hosts

/25 255.255.255.128 = 128 hosts

/24 255.255.255.0 = 256 hosts

/23 255.255.254.0 = 512 hosts

/22 255.255.252.0 = 1024 hosts

/21 255.255.248.0 = 2048 hosts

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