What does the CIDR slash notation mean in IP addresses e.g. 63.245.214.128/26 ?

Pontifications

Classless Inter Domain Routing aka CIDR notation means you have to apply a bit mask for the number of bits after the slash so in our example 63.245.214.128/26 that means 26 bit bit mask.

• # of valid IP addresses 2^(32-n) where “n” is the number after the slash
• 63.245.214.128/26 = 2^(32-26) = 2^6 = 64 valid IP addresses
  • which are: 63.245.214.128 to 63.245.214.191
• More info:
  • https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#CIDR_notation
  • https://en.wikipedia.org/wiki/IP_address
  • cidr range to ip address range converter

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