Arch Linux

carloabelli

Member

Registered: 2021-06-12

Posts: 1

iwd + MulticastDNS

I can't seem to get systemd-resolved mDNS working with iwd. Currently getting:

~ resolvectl
Global
         Protocols: LLMNR=resolve mDNS=resolve +DNSOverTLS DNSSEC=no/unsupported
  resolv.conf mode: stub
Current DNS Server: 94.140.14.14
       DNS Servers: 94.140.14.14 94.140.15.15

Link 8 (wlan0)
    Current Scopes: DNS LLMNR/IPv4
         Protocols: +DefaultRoute +LLMNR -mDNS +DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 1.1.1.1
       DNS Servers: 1.1.1.1 1.0.0.1
~ resolvectl mdns
Global: resolve
Link 8 (wlan0): no
~ resolvectl query BRW441CA83882BE.local
BRW441CA83882BE.local: resolve call failed: No appropriate name servers or networks for name found

Looks like mDNS is disabled on the link.

Additional info:

~ iwctl version
NetworkConfigurationEnabled: enabled
StateDirectory: /var/lib/iwd
Version: 1.29
~ systemctl --version
systemd 251 (251.4-1-arch)
+PAM +AUDIT -SELINUX -APPARMOR -IMA +SMACK +SECCOMP +GCRYPT +GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS +FIDO2 +IDN2 -IDN +IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 -PWQUALITY +P11KIT -QRENCODE +TPM2 +BZIP2 +LZ4 +XZ +ZLIB +ZSTD -BPF_FRAMEWORK +XKBCOMMON +UTMP -SYSVINIT default-hierarchy=unified

/etc/iwd/main.conf

[General]
AddressRandomization=network
EnableNetworkConfiguration=true

[Network]
MulticastDNS=resolve

/etc/systemd/resolved.conf

#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it under the
#  terms of the GNU Lesser General Public License as published by the Free
#  Software Foundation; either version 2.1 of the License, or (at your option)
#  any later version.
#
# Entries in this file show the compile time defaults. Local configuration
# should be created by either modifying this file, or by creating "drop-ins" in
# the resolved.conf.d/ subdirectory. The latter is generally recommended.
# Defaults can be restored by simply deleting this file and all drop-ins.
#
# Use 'systemd-analyze cat-config systemd/resolved.conf' to display the full config.
#
# See resolved.conf(5) for details.

[Resolve]
DNS=94.140.14.14 94.140.15.15
FallbackDNS=
#Domains=
#DNSSEC=no
DNSOverTLS=yes
MulticastDNS=resolve
LLMNR=resolve
#Cache=yes
#CacheFromLocalhost=no
#DNSStubListener=yes
#DNSStubListenerExtra=
#ReadEtcHosts=yes
#ResolveUnicastSingleLabel=no

Based off

man 5 iwd.config

seems like the MulticastDNS setting should do it, but doesn't seem to have any effect.

                          ├─────────────────────┼──────────────────────────────────────┤
                          │MulticastDNS         │ Values: true, false, resolve         │
                          │                     │                                      │
                          │                     │ Configures multicast DNS on each in‐ │
                          │                     │ terface.  If  not  specified,   sys‐ │
                          │                     │ temd-resolved's  default  value will │
                          │                     │ remain untouched.  See  man  5  sys‐ │
                          │                     │ temd.network for details.            │
                          │                     │                                      │
                          │                     │ Only  applies when NameResolvingSer‐ │
                          │                     │ vice=systemd.                        │
                          └─────────────────────┴──────────────────────────────────────┘

I tried changing all the MulticastDNS settings to yes/true to no avail as well. Was wondering if anyone has seen anything similar or has any tips for getting it to work.

jaerri

Member

Registered: 2024-05-05

Posts: 2

Re: iwd + MulticastDNS

It seems like you are missing `NameResolvingService=systemd` in /etc/iwd/main.conf.

                          ├─────────────────────┼──────────────────────────────────────┤
                          │MulticastDNS         │ Values: true, false, resolve         │
                          │                     │                                      │
                          │                     │ Configures multicast DNS on each in‐ │
                          │                     │ terface.  If  not  specified,   sys‐ │
                          │                     │ temd-resolved's  default  value will │
                          │                     │ remain untouched.  See  man  5  sys‐ │
                          │                     │ temd.network for details.            │
                          │                     │                                      │
                          │                     │ Only  applies when NameResolvingSer‐ │
                          │                     │ vice=systemd.                        │
                          └─────────────────────┴──────────────────────────────────────┘

This also means that you have to use systemd-resolved as your DNS resolver. See https://wiki.archlinux.org/title/iwd#Select_DNS_manager

Head_on_a_Stick

Member

From: The Wirral

Registered: 2014-02-20

Posts: 8,631

Website

Re: iwd + MulticastDNS

In my system just setting MulticastDNS=true in resolved.conf seems to do the trick:

~$ resolvectl --no-p mdns wlan0
Link 4 (wlan0): yes
~$

I'm using systemd-resolved as a consumer rather than a provider (ie, resolv.conf is manually populated) and iwd's main.conf has no [Network] section.

---

Jin, Jiyan, Azadî