avahi-autoipd

Acquire IPv4 link-local addresses automatically

TLDR

Start the daemon on an interface to auto-configure an IPv4LL address

$ avahi-autoipd [interface]

Run in background (daemonize) after startup

$ avahi-autoipd -D [interface]

Kill a running daemon on an interface

$ avahi-autoipd --kill [interface]

Refresh and re-announce the acquired IP address

$ avahi-autoipd --refresh [interface]

Check if daemon is running on an interface

$ avahi-autoipd --check [interface]

Wait for successful IP acquisition before detaching

$ avahi-autoipd --wait [interface]

SYNOPSIS

avahi-autoipd [options] interface

avahi-autoipd implements IPv4LL (Dynamic Configuration of IPv4 Link-Local Addresses), a protocol defined in IETF RFC3927 for automatic IP address configuration from the link-local 169.254.0.0/16 range without requiring a central server.
Primarily intended for ad-hoc networks which lack a DHCP server, it serves as a core component of the Zeroconf stack. The daemon can operate standalone or integrate with DHCP clients as a fallback mechanism when DHCP is unavailable.
When started, avahi-autoipd probes the network for address conflicts, acquires an available link-local address, and continuously monitors for conflicts. Upon successful acquisition, it executes /etc/avahi/avahi-autoipd.action script to configure the network interface.
The daemon responds to signals: SIGINT and SIGTERM trigger shutdown, while SIGHUP forces re-announcement of the current IP address.

PARAMETERS

-D, --daemonize

Daemonize after startup; implies syslog logging

-k, --kill

Terminate running daemon on specified interface

-r, --refresh

Re-announce acquired IP address (equivalent to SIGHUP)

-c, --check

Return 0 if daemon is running on interface

-s, --syslog

Log to syslog instead of STDERR

--debug

Enable verbose mode for detailed logging

--no-drop-root

Retain root privileges (not recommended for security)

--no-chroot

Skip chroot operation

-S, --start=address

Acquire the specified IPv4LL address

-w, --wait

Wait for successful IP acquisition before detaching

--force-bind

Acquire IPv4LL address even if routable address is present

--no-proc-title

Don't modify process name during operation

-h, --help

Display help information

-v, --version

Show version details

CAVEATS

Link-local addresses (169.254.0.0/16) only enable communication within the same network segment—no routing to other networks. Won't assign addresses if a routable IP already exists unless --force-bind is used.

HISTORY

Part of the Avahi project, developed as a free software implementation of Apple's Bonjour/Zeroconf protocols. IPv4LL support was standardized in RFC3927 in 2005, with avahi-autoipd emerging as a lightweight standalone implementation for Linux systems.