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iptool subnet split

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mikael edited this page Feb 18, 2024 · 1 revision

Introduction

The iptool subnet split command can be used to split a network of any size into smaller subnets.

Choose to create networks of a given size (ex, --bits 30) or the number of subnets to split the network into (ex, --networks 4)

Usage

Use the iptool subnet split to see the available options.

Usage:
  iptool subnet split <subnet> [flags]

Flags:
  -b, --bits int             subnet size in bits for network division
  -c, --csv                  output in CSV format
  -h, --help                 help for split
  -l, --limit int            limit the number of subnets in the output
  -n, --networks int         number of subnets to divide the network into
  -o, --output-file string   write output to file

Output

Split by number of bits

As an example we can split a network 10.192.16.0/24 into smaller /30 subnets using the --bits (or -b) argument.

Command

iptool subnet split 10.192.16.0/24 --bits 30

Output

This will print all 64 subnets in sequence. Note: the output is truncated

Prefix            Network        First          Last           Broadcast      Hosts
-----------------------------------------------------------------------------------
10.192.16.0/30    10.192.16.0    10.192.16.1    10.192.16.2    10.192.16.3    2
10.192.16.4/30    10.192.16.4    10.192.16.5    10.192.16.6    10.192.16.7    2
10.192.16.8/30    10.192.16.8    10.192.16.9    10.192.16.10   10.192.16.11   2
...
10.192.16.244/30  10.192.16.244  10.192.16.245  10.192.16.246  10.192.16.247  2
10.192.16.248/30  10.192.16.248  10.192.16.249  10.192.16.250  10.192.16.251  2
10.192.16.252/30  10.192.16.252  10.192.16.253  10.192.16.254  10.192.16.255  2

Limit output

Use the --limit (or -l) argument to limit the number of subnets output. This way we can display only the first number of subnets in case there are many.

Command

iptool subnet split 10.192.16.0/24 --bits 30 --limit 4

Output

Prefix            Network        First          Last           Broadcast      Hosts
-----------------------------------------------------------------------------------
10.192.16.0/30    10.192.16.0    10.192.16.1    10.192.16.2    10.192.16.3    2
10.192.16.4/30    10.192.16.4    10.192.16.5    10.192.16.6    10.192.16.7    2
10.192.16.8/30    10.192.16.8    10.192.16.9    10.192.16.10   10.192.16.11   2
10.192.16.12/30   10.192.16.12   10.192.16.13   10.192.16.14   10.192.16.15   2

Split into a number of networks

Use the --networks (or -n) argument to split the given network into a number of subnets.

Command

iptool subnet split 10.192.16.0/24 --networks 4

Output

Prefix            Network        First          Last           Broadcast      Hosts
-----------------------------------------------------------------------------------
10.192.16.0/26    10.192.16.0    10.192.16.1    10.192.16.62   10.192.16.63   62
10.192.16.64/26   10.192.16.64   10.192.16.65   10.192.16.126  10.192.16.127  62
10.192.16.128/26  10.192.16.128  10.192.16.129  10.192.16.190  10.192.16.191  62
10.192.16.192/26  10.192.16.192  10.192.16.193  10.192.16.254  10.192.16.255  62

Output in CSV format

Use the --csv (or -c) flag to format the output in CSV format.

Command

iptool subnet split 10.192.16.0/24 --networks 4 --csv

Output

prefix,network,first,last,broadcast,hosts
10.192.16.0/26,10.192.16.0,10.192.16.1,10.192.16.62,10.192.16.63,62
10.192.16.64/26,10.192.16.64,10.192.16.65,10.192.16.126,10.192.16.127,62
10.192.16.128/26,10.192.16.128,10.192.16.129,10.192.16.190,10.192.16.191,62
10.192.16.192/26,10.192.16.192,10.192.16.193,10.192.16.254,10.192.16.255,62

Save output to file

Use the --output-file (or -o) argument to redirect the output to a file.

Command

iptool subnet split 10.192.16.0/24 --networks 4 --csv --output-file test.txt

Note: No output is displayed in the terminal when using this argument.

FAQs

  1. FAQs

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