Manpages

NAME

avahi-daemon.conf - avahi-daemon configuration file

SYNOPSIS

/etc/avahi/avahi-daemon.conf

DESCRIPTION

avahi-daemon.conf is the configuration file for avahi-daemon.

SECTION [SERVER]

host-name= Set the host name avahi-daemon tries to register on the LAN.
If omited defaults to the system host name as set with the
sethostname() system call.
host-name-from-machine-id= Takes a boolean value ("yes" or "no"). If
set to "yes" avahi-daemon will use the machine-id as name on the LAN.
domain-name= Set the default domain name avahi-daemon tries to register
its host name and services on the LAN in. If omitted defaults to
".local".
browse-domains= Set a comma separated list of browsing domains (in
addition to the default one and those announced inside the default
browsing domain). Please note that the user may specify additional
browsing domains on the client side, either by setting
$AVAHI_BROWSE_DOMAINS to a list of colon separated domains or by adding
them to the XDG config file ~/.config/avahi/browse-domains (separated
by newlines).
use-ipv4= Takes a boolean value ("yes" or "no"). If set to "no"
avahi-daemon will not use IPv4 sockets. Default is "yes".
use-ipv6= Takes a boolean value ("yes" or "no"). If set to "no"
avahi-daemon will not use IPv6 sockets. Default is "yes".
allow-interfaces= Set a comma separated list of allowed network
interfaces that should be used by the avahi-daemon. Traffic on other
interfaces will be ignored. If set to an empty list all local
interfaces except loopback and point-to-point will be used.
deny-interfaces= Set a comma separated list of network interfaces that
should be ignored by avahi-daemon. Other not specified interfaces will
be used, unless allow-interfaces= is set. This option takes precedence
over allow-interfaces=.
check-response-ttl= Takes a boolean value ("yes" or "no"). If set to
"yes", an additional security check is activated: incoming IP packets
will be ignored unless the IP TTL is 255. Earlier mDNS specifications
required this check. Since this feature may be incompatible with newer
implementations of mDNS it defaults to "no". On the other hand it
provides extra security.
use-iff-running= Takes a boolean value ("yes" or "no"). If set to "yes"
avahi-daemon monitors the IFF_RUNNING flag bit which is used by some
(modern) network drivers to tell user space if a network cable is
plugged in (in case of copper ethernet), or the network card is
associated with some kind of network (in case of WLAN). If IFF_RUNNING
is set avahi-daemon will automatically announce its services on that
network. Unfortunately far too many network drivers do not support this
flag or support it in a broken way. Therefore this option defaults to
"no".
enable-dbus= Takes either "yes", "no" or "warn". If set to "yes"
avahi-daemon connects to D-Bus, offering an object oriented client API.
It is only available if Avahi has been compiled with --enable-dbus in
which case it defaults to "yes". "warn" behaves like "yes", but the
daemon starts up even when it fails to connect to a D-Bus daemon. In
addition, if the connection to the D-Bus daemon is terminated we try to
reconnect. (Unless we are in a chroot() environment where this
definitely will fail.)
disallow-other-stacks= Takes a boolean value ("yes" or "no"). If set to
"yes" no other process is allowed to bind to UDP port 5353. This
effectively impedes other mDNS stacks from running on the host. Use
this as a security measure to make sure that only Avahi is responsible
for mDNS traffic. Please note that we do not recommend running multiple
mDNS stacks on the same host simultaneously. This hampers reliability
and is a waste of resources. However, to not annoy people this option
defaults to "no".
allow-point-to-point= Takes a boolean value ("yes" or "no"). If set to
"yes" avahi-daemon will make use of interfaces with the POINTOPOINT
flag set. This option defaults to "no" as it might make mDNS unreliable
due to usually large latencies with such links and opens a potential
security hole by allowing mDNS access from Internet connections. Use
with care and YMMV!
cache-entries-max= Takes an unsigned integer specifying how many
resource records are cached per interface. Bigger values allow mDNS
work correctly in large LANs but also increase memory consumption.
clients-max= Takes an unsigned integer. The maximum number of
concurrent D-Bus clients allowed. If the maximum number is reached
further clients will be refused until at least one existing client
disconnects.
objects-per-client-max= Takes an unsigned integer. The maximum number
of objects (entry groups, browsers, resolvers) that may be registered
per D-Bus client at a time. If the maximum number is reached further
object creation will be refused until at least one object is freed.
entries-per-entry-group-max= Takes an unsigned integer. The maximum
number of entries (resource records) per entry group registered by a
D-Bus client at a time. If the maximum number is reached further
resource records may not be added to an entry group.
ratelimit-interval-usec= Takes an unsigned integer. Sets the
per-interface packet rate-limiting interval parameter. Together with
ratelimit-burst= this may be used to control the maximum number of
packets Avahi will generated in a specific period of time on an
interface.
ratelimit-burst= Takes an unsigned integer. Sets the per-interface
packet rate-limiting burst parameter. Together with
ratelimit-interval-usec= this may be used to control the maximum number
of packets Avahi will generated in a specific period of time on an
interface.

SECTION [WIDE-AREA]

enable-wide-area= Takes a boolean value ("yes" or "no"). Enable
wide-area DNS-SD, aka DNS-SD over unicast DNS. If this is enabled only
domains ending in .local will be resolved on mDNS, all other domains
are resolved via unicast DNS. If you want to maintain multiple
different multicast DNS domains even with this option enabled we
encourage you to use subdomains of .local, such as "kitchen.local".
This option defaults to "yes".

SECTION [PUBLISH]

disable-publishing= Takes a boolean value ("yes" or "no"). If set to
"yes", no record will be published by Avahi, not even address records
for the local host. Avahi will be started in a querying-only mode. Use
this is a security measure. This option defaults to "no"
disable-user-service-publishing= Takes a boolean value ("yes" or "no").
If set to "yes", Avahi will still publish address records and suchlike
but will not allow user applications to publish services. Use this is a
security measure. This option defaults to "no"
add-service-cookie= Takes a boolean value ("yes" or "no"). If set to
"yes" an implicit TXT entry will be added to all locally registered
services, containing a cookie value which is chosen randomly on daemon
startup. This can be used to detect if two services on two different
interfaces/protocols are actually identical. Defaults to "no".
publish-addresses= Takes a boolean value ("yes" or "no"). If set to
"yes" avahi-daemon will register mDNS address records for all local IP
addresses. Unless you want to use avahi-daemon exclusively for browsing
it’s recommended to enable this. If you plan to register local services
you need to enable this option. Defaults to "yes".
publish-hinfo= Takes a boolean value ("yes" or "no"). If set to "yes"
avahi-daemon will register an mDNS HINFO record on all interfaces which
contains information about the local operating system and CPU, which
might be useful for administrative purposes. This is recommended by the
mDNS specification but not required. For the sake of privacy you might
choose to disable this feature. Defaults to "no".
publish-workstation= Takes a boolean value ("yes" or "no"). If set to
"yes" avahi-daemon will register a service of type "_workstation._tcp"
on the local LAN. This might be useful for administrative purposes
(i.e. browse for all PCs on the LAN), but is not required or
recommended by any specification. Newer MacOS X releases register a
service of this type. Defaults to "no".
publish-domain= Takes a boolean value ("yes" or "no"). If set to "yes"
avahi-daemon will announce the locally used domain name (see above) for
browsing by other hosts. Defaults to "yes".
publish-dns-servers= Takes a comma separated list of IP addresses for
unicast DNS servers. You can use this to announce unicast DNS servers
via mDNS. When used in conjunction with avahi-dnsconfd on the client
side this allows DHCP-like configuration of unicast DNS servers.
publish-resolv-conf-dns-servers= Takes a boolean value ("yes" or "no").
If set to "yes" avahi-daemon will publish the unicast DNS servers
specified in /etc/resolv.conf in addition to those specified with
publish-dns-servers. Send avahi-daemon a SIGHUP to have it reload this
file. Defaults to "no".
publish-aaaa-on-ipv4= Takes a boolean value ("yes" or "no"). If set to
"yes" avahi-daemon will publish an IPv6 AAAA record via IPv4, i.e. the
local IPv6 addresses can be resolved using an IPv4 transport. Only
useful when IPv4 is enabled with use-ipv4=true. Defaults to "yes".
publish-a-on-ipv6= Takes a boolean value ("yes" or "no"). If set to
"yes" avahi-daemon will publish an IPv4 A record via IPv6, i.e. the
local IPv4 addresses can be resolved using an IPv6 transport. Only
useful when IPv6 is enabled with use-ipv6=true. Defaults to "no".

SECTION [REFLECTOR]

enable-reflector= Takes a boolean value ("yes" or "no"). If set to
"yes" avahi-daemon will reflect incoming mDNS requests to all local
network interfaces, effectively allowing clients to browse mDNS/DNS-SD
services on all networks connected to the gateway. The gateway is
somewhat intelligent and should work with all kinds of mDNS traffic,
though some functionality is lost (specifically the unicast reply bit,
which is used rarely anyway). Make sure to not run multiple reflectors
between the same networks, this might cause them to play Ping Pong with
mDNS packets. Defaults to "no".
reflect-ipv= Takes a boolean value ("yes" or "no"). If set to "yes" and
enable-reflector is enabled, avahi-daemon will forward mDNS traffic
between IPv4 and IPv6, which is usually not recommended. Defaults to
"no".
reflect-filters= Set a comma separated list of allowed service names to
be reflected. Each service that is seen must match an entry in this
list to be reflected to other networks. This list can match the type of
service or the name of the machine providing the service. Defaults to
allowing all services.

SECTION [RLIMITS]

This section is used to define system resource limits for the daemon. See setrlimit(2) for more information. If any of the options is not specified in the configuration file, avahi-daemon does not change it from the system defaults.
rlimit-as= Value in bytes for RLIMIT_AS (maximum size of the process’s
virtual memory). Sensible values are heavily system dependent.
rlimit-core= Value in bytes for RLIMIT_CORE (maximum core file size).
Unless you want to debug avahi-daemon, it is safe to set this to 0.
rlimit-data= Value in bytes for RLIMIT_DATA (maximum size of the
process’s data segment). Sensible values are heavily system dependent.
rlimit-fsize= Value for RLIMIT_FSIZE (maximum size of files the process
may create). Since avahi-daemon shouldn’t write any files to disk, it
is safe to set this to 0.
rlimit-nofile= Value for RLIMIT_NOFILE (open file descriptors).
avahi-daemon shouldn’t need more than 15 to 20 open file descriptors
concurrently.
rlimit-stack= Value in bytes for RLIMIT_STACK (maximum size of the
process stack). Sensible values are heavily system dependent.
rlimit-nproc= Value for RLIMIT_NPROC (max number of processes a user
can launch). avahi-daemon forks of a helper process on systems where
chroot(2) is available therefore this value should not be set below 2.
Note that while the process limit only applies to this process, the
total count of processes to reach that limit includes all processes on
the system with the same UID, including any containers without UID
remapping (such as lxd containers with security.privileged=true). The
default configuration of 3 was removed to prevent problems in this
scenario.