---
name: "pknlusr"
section: "8"
platform: "linux"
package: "xtables-addons-common"
version: "3.27-4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/pknlusr"
---

# pknlusr(8)

userspace monitor for successful xt\_pknock matches

## NAME

pknlusr — userspace monitor for successful xt\_pknock matches

## Synopsis

**pknlusr** \[*group-id*\]

## Description

*xt\_pknock* is an xtables match extension that implements so-called *port* *knocking*. It can be configured to send information about each successful match via a netlink socket to userspace. **pknluser** listens for these notifications.

By default, **pknlusr** listens for messages sent to netlink multicast group 1. Another group ID may be passed as a command-line argument.

## See also

[xtables-addons(8)](/xtables-addons/8.md)