---
name: "aggregate"
section: "8"
platform: "linux"
package: "aggregate"
version: "1.0.2-2"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/aggregate/8"
---

# aggregate(8)

tool for aggregating CIDR networks

## NAME

aggregate - tool for aggregating CIDR networks

## SYNOPSIS

**aggregate** \[options\]

## DESCRIPTION

[**aggregate**(8)](/aggregate/8.md) is a tool for aggregating CIDR networks. Input is read from stdin and output is written to stdout. It undestands IPv4 networks represented as network/prefix, network/netmask and start\_address - end\_addres. It is able to read input in any one of these formats and output in the same or a different format.

It is also able to limit the maximum and minimum prefix length that will be output. This can be used to filter, for instance ignoring all networks with a prefix longer than 24 bits. That is all networks smaller than a traditional Class C.

## OPTIONS

- **-h, --help:**

  Display terse help.

- **-i, --input-format FORMAT:**

  Format for input. One of:

  **prefix:** network/prefix. \
   e.g. 10.0.0.0/24

  **netmask:** network/netmask. \
   e.g. 10.0.0.0/255.255.255.0

  **range:** start\_ip - end\_ip. \
   e.g. 10.0.0.0 - 10.0.0.255

  Note that while prefix and netmask types imply a single CIDR network, a range may span multiple CIDR networks.

  The default is prefix.

- **-M, --maximum-format FORMAT:**

  Supress the output of networks whose prefix is greater than this value. Valid values 0-32. -1 for no maximum prefix. Default is -1.

- **-m, --minimum-format FORMAT:**

  Supress netorks whose prefix is less than this value. Valid values 0-32. -1 for no minimum prefix. Default is -1.

- **-o, --output-format FORMAT:**

  Format for intput. Available formats are as per --input-format. Defailt is prefix.

## EXAMPLES

- **Example 1:**

  Aggregate some prefixes.

  ```
  aggregate
  10.0.0.0/19
  10.0.255.0/24
  10.1.0.0/24
  10.1.1.0/24
  10.1.2.0/24
  10.1.2.0/25
  10.1.2.128/25
  10.1.3.0/25
  ^D
  10.0.0.0/19
  10.0.255.0/24
  10.1.0.0/23
  10.1.2.0/24
  10.1.3.0/25
  ```

- **Example 2:**

  Aggregate some prefixes ignoring anything smaller than a /24.

  ```
  aggregate -M 24
  10.0.0.0/19
  10.0.255.0/24
  10.1.0.0/24
  10.1.1.0/24
  10.1.2.0/24
  10.1.2.0/25
  10.1.2.128/25
  10.1.3.0/25
  ^D
  10.0.0.0/19
  10.0.255.0/24
  10.1.0.0/23
  10.1.2.0/24
  ```

- **Example 3:**

  Same as example 1 but input is in  **netmask** format and output is in  **range** format

  ```
  aggregate -i netmask
  10.0.0.0/255.255.224.0
  10.0.255.0/255.255.255.0
  10.1.0.0/255.255.255.0
  10.1.1.0/255.255.255.0
  10.1.2.0/255.255.255.0
  10.1.2.0/255.255.255.128
  10.1.2.128/255.255.255.128
  10.1.3.0/255.255.255.128
  ^D
  10.0.0.0 - 10.0.31.255
  10.0.255.0 - 10.0.255.255
  10.1.0.0 - 10.1.1.255
  10.1.2.0 - 10.1.2.255
  10.1.3.0 - 10.1.3.127
  ```

## AUTHOR

Horms \<horms@verge.net.au\>