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IP Addressing

Subnet Divider (FLSM)

Enter a base network and split it into equal-size subnets: by subnet count, by new prefix or by hosts per subnet. I list them all with mask, range, broadcast and hosts. All in your browser.

Format network/prefix, e.g. 192.168.1.0/24. If you type host bits, I align to the network.

Pick the criterion: how many subnets, which prefix, or how many usable hosts each subnet needs.

I borrow bits up to the nearest power of 2 that covers your count.

redzilla.cl — flsm 
 
  
 
 
New prefix
 
—
 
mask
 
 
 
Subnets
 
0
 
borrowed bits
 
 
 
Block size
 
0
 
addresses each
 
 
 
Usable hosts
 
0
 
per subnet
 
 
  
 
 Prefix /26  
 
 Mask 255.255.255.192  
 
 Step 64  
 
  
 Generated subnets 
 
  
 # Network / CIDR Mask 1st host Last host Broadcast Usable 
   
 
  
 

FLSM splits the base network into equal-size subnets: they
        all share the same prefix and the same step. When you fix by subnet count I
        borrow bits up to the nearest power of 2, so the real count
        may be larger than requested. With hosts per subnet I always reserve
network and broadcast.

 
 
 
Runs locally in your browser · no sign-up · nothing leaves your browser
    
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