# ipv4.mode

Selects the IPv4 anonymization mode used by the mmanon action.

This parameter applies to IP Address Anonymization Module (mmanon).

Name:

  ipv4.mode

Scope:

  input

Type:

  string

Default:

  input=zero

Required?:

  no

Introduced:

  7.3.7

## Description

The available modes are `simple`, `random`, `random-consistent`, and `zero`. In simple mode, only octets as a whole can be anonymized and the length of the message is never changed. This means that when the last three octets of the address 10.1.12.123 are anonymized, the result will be 10.x.xx.xxx. The replacement character is configurable via ipv4.replaceChar. This means that the length of the original octets is still visible and may be used to draw some privacy-evasive conclusions. This mode is slightly faster than the other modes, and this may matter in high throughput environments.

The modes `random` and `random-consistent` are very similar, in that they both anonymize IP addresses by randomizing the last bits (any number) of a given address. However, while `random` mode assigns a new random IP address for every address in a message, `random-consistent` will assign the same randomized address to every instance of the same original address.

The default `zero` mode will do full anonymization of any number of bits. It will also normalize the address, so that no information about the original IP address is available. For example, if 24 bits are anonymized, 10.1.12.123 would be anonymized to 10.0.0.0.

## Input usage

    module(load="mmanon")
    action(type="mmanon" ipv4.mode="random-consistent")

### Legacy names (for reference)

Historic names/directives for compatibility. Do not use in new configs.

- mode — maps to ipv4.mode (status: legacy)

## See also

IP Address Anonymization Module (mmanon)

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