MapCIDR : Small Utility Program To Perform Multiple Operations For A Given sub-net/CIDR Ranges

MapCIDR is a small utility program to perform multiple operations for a given subnet/CIDR ranges.

The tool was developed to ease load distribution for mass scanning operations, it can be used both as a library and as independent CLI tool.


  • Simple and modular code base making it easy to contribute.
  • CIDR distribution for distributed scanning.
  • Stdin and stdout support for integrating in workflows


  • From Source

▶ GO111MODULE=auto go get -u

  • From Github

▶ git clone; cd mapcidr/cmd/mapcidr; go build .; cp mapcidr /usr/local/bin


▶ mapcidr -h

This will display help for the tool. Here are all the switches it supports.

-cidrSingle CIDR to processmapcidr -cidr
-sbcSlice by CIDR countmapcidr -sbc 10
-sbhSlice by HOST countmapcidr -sbh 10000
-lFile containing list of CIDRsmapcidr -l cidr.txt
-oFile to write output to (optional)mapcidr -o output.txt
-silentMake the output silentmapcidr -silent
-versionPrint current version of mapcidr clientmapcidr -version

Running mapCIDR

In order to get list of IPs for a give CIDR, use the following command.

▶ mapcidr -cidr
▶ echo | mapcidr

Slice by CIDR

In order to slice given CIDR or list of CIDR by CIDR count or slice into multiple and equal smaller subnets, use the following command.

▶ mapcidr -cidr -sbc 10 -silent
▶ echo | mapcidr -sbc 10 -silent

Slice by HOST

In order to slice given CIDR for equal number of host count in each CIDR, use the following command.

▶ mapcidr -cidr -sbh 20000 -silent
▶ echo | mapcidr -sbh 20000 -silent

Note: it’s possible to obtain a perfect split only when the desired amount of slices or hosts per subnet is a powers of two. Otherwise the tool will attempt to automatically find the best split strategy to obtain the desired outcome.

Use mapCIDR as a library

It’s possible to use the library directly in your go programs. The following code snippets outline how to divide a cidr into subnets, and how to divide the same into subnets containing a certain number of hosts

package main
import (
func main() {
// Divide the CIDR into two subnets
subnets1 := mapcidr.SplitN(“”, 2)
for , subnet := range subnets1 { fmt.Println(subnet) } // Divide the CIDR into two subnets containing 128 hosts each subnets2 := mapcidr.SplitByNumber(“”, 128) for , subnet := range subnets2 {
// List all ips in the CIDR
ips, _ := mapcidr.Ips(“”)
for _, ip := range ips {

mapCDIR is made with 🖤 by the projectdiscovery team.