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| '''Avahi''' is an implementation of '''Zeroconf''', the zero-configuration method for network services. This would otherwise be accomplished through local DNS resolution. | '''Avahi''' is an implementation of Zeroconf and mDNS. The project began with Lennart Poettering's implementation of mDNS and DNS-SD. |
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| Most [[Linux]] distributions offer an `avahi` package. For [[BSD]] distributions, try `avahi-daemon`. For `systemd`-capable systems, [[Linux/Systemd|start and enable]] `avahi-daemon.service`. The daemon binary is named `avahi-daemon(8)`. |
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| == Advertising Services == | == Configuration == |
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| Avahi uses all `/etc/avahi/services/*.service` files that are readable by the `avahi` user and group. These take the form of structured XML. For example, an FTP service: | [[Linux/SystemdNetworkd|networkd]] has a competing mDNS implementation that will need to be disabled before `avahi` can be made to work. Alternatively, [[Linux/Systemd|disable]] `systemd-resolved.service` entirely. === Name Resolution === For Avahi to insert domain name resolution for discovered services, an additional dependency (commonly named `nss-mdns`) is required. Insert `mdns_minimal [NOTFOUND=return]` into `/etc/nsswitch.conf`, as below. {{{ hosts: files mymachines myhostname mdns_minimal [NOTFOUND=return] resolve [!UNAVAIL=return] dns }}} === Firewalls === `avahi-daemon(8)` binds to port 5353. Firewalls such as [[Ufw|ufw]] or [[Awall|awall]] must be reconfigured to open it. ---- == Usage == === Advertising Services === `avahi-daemon(8)` uses all `/etc/avahi/services/*.service` files that are readable by the `avahi` user and group. These take the form of structured XML. For example, an FTP service: |
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| === Networking === | === Discovery === |
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| Avahi broadcasts over port 5353. A common pitfall is failing to account for this in the firewall. See details in the articles for [[UFW|UFW]]. | In a terminal, use `avahi-browse(1)`. {{{ avahi-browse --all }}} Alternatively there is the graphical client `avahi-discover(1)`. |
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| == Inspecting Services == | == See also == |
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| === Name Resolution === | [[https://man.archlinux.org/man/extra/avahi/avahi-daemon.8.en|avahi-daemon(8)]] |
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| To make use of the `.local` domain, an additional dependency (commonly named `nss-mdns`) is required. | [[https://man.archlinux.org/man/extra/avahi/avahi-browse.1.en|avahi-browse(1)]] |
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| Insert `mdns_minimal [NOTFOUND=return]` into `/etc/nsswitch.conf`, as below. {{{ hosts: files mymachines myhostname mdns_minimal [NOTFOUND=return] resolve [!UNAVAIL=return] dns }}} === Terminal === {{{ avahi-browse --all }}} |
[[https://man.archlinux.org/man/extra/avahi/avahi-discover.1.en|avahi-discover(1)]] |
Avahi
Avahi is an implementation of Zeroconf and mDNS.
The project began with Lennart Poettering's implementation of mDNS and DNS-SD.
Contents
Installation
Most Linux distributions offer an avahi package. For BSD distributions, try avahi-daemon.
For systemd-capable systems, start and enable avahi-daemon.service.
The daemon binary is named avahi-daemon(8).
Configuration
networkd has a competing mDNS implementation that will need to be disabled before avahi can be made to work.
Alternatively, disable systemd-resolved.service entirely.
Name Resolution
For Avahi to insert domain name resolution for discovered services, an additional dependency (commonly named nss-mdns) is required.
Insert mdns_minimal [NOTFOUND=return] into /etc/nsswitch.conf, as below.
hosts: files mymachines myhostname mdns_minimal [NOTFOUND=return] resolve [!UNAVAIL=return] dns
Firewalls
avahi-daemon(8) binds to port 5353. Firewalls such as ufw or awall must be reconfigured to open it.
Usage
Advertising Services
avahi-daemon(8) uses all /etc/avahi/services/*.service files that are readable by the avahi user and group. These take the form of structured XML. For example, an FTP service:
<?xml version="1.0" standalone='no'?>
<!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
<name>FTP</name>
<service>
<type>_ftp._tcp</type>
<port>21</port>
</service>
</service-group>
Discovery
In a terminal, use avahi-browse(1).
avahi-browse --all
Alternatively there is the graphical client avahi-discover(1).