1.3.9 • Public • Published


A small utility to manipulate prefixes. There are other possible solutions on npm, this was created mostly to prioritize performance.

It implements the following methods.

  • getIpAndCidr - if you provide "" it returns ["", 24]

  • isValidPrefix - it returns true/false

  • isValidIP - it returns true/false

  • sortByPrefix - it is a sorting function for an array or prefixes. It sorts the array based on the entire prefix.

  • sortByPrefixLength - it is a sorting function for an array or prefixes. It sorts the array based on the amount of bits of the netmask (from less specific to more specific).

  • expandIP - if you provide something like "127/8", you will receive "". If you provide "2001:db8:123::", you will receive "2001:0db8:0123:0000:0000:0000:0000:0000". In case of IPv6, you can also do expandIP("2001:db8:123::", true) to obtain the expanded-shortened version "2001:db8:123:0:0:0:0:0" (without 0 padding).

  • isEqualIP - it checks for IP equality, it takes into account expansions and cases. E.g. "2001:db8:123::" is equal to "2001:DB8:123::0"

  • isEqualPrefix - same as above, but with prefixes

  • getAddressFamily - it returns 4 or 6 (integers)

  • toBinary - it returns the binary representation of the IP

  • fromBinary - it returns the decimal/hexadecimal representation of a binary IP (essentially, the opposite of the previous function)

  • applyNetmask - it applies the netmask. E.g., if you provide "" you will get the binary representation of "" truncated at 24 bits

  • isSubnet - you provide two prefixes and you will get true if the second one is subnet of the first one.

  • isSubnetBinary - same as above but directly with binary representation

  • cidrToRange - given a prefix in cidr notation, it returns the first and last ip address of the range.


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  • maxcam