Table of Contents
Systemd-resolved
Systemd-resolved provides resolver services for Domain Name System (DNS).
Status
To check the DNS currently in use by systemd-resolved, run resolvectl status.
# resolvectl status
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Global
Protocols: +LLMNR +mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: stub
Link 2 (eth0)
Current Scopes: DNS LLMNR/IPv4 LLMNR/IPv6
Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: fdaa:66:67:a::1
DNS Servers: fdaa:66:67:a::1
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Query
# resolvectl query www.oscardegroot.nl
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www.oscardegroot.nl: 2001:1c00:2e16:720a:2ff:b1ff:feaa:1202 -- link: eth0
84.31.73.82 -- link: eth0
(oscardegroot.nl)
-- Information acquired via protocol DNS in 3.5ms.
-- Data is authenticated: no; Data was acquired via local or encrypted transport: no
-- Data from: network
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Configure
Supporting /etc/resolv.conf
To provide domain name resolution for software that reads /etc/resolv.conf directly, such as web browsers, systemd-resolved has four different modes for handling the file—stub, static, uplink and foreign. They are described in systemd-resolved(8). The recommended mode, is the stub mode which uses /run/systemd/resolve/stub-resolv.conf. /run/systemd/resolve/stub-resolv.conf contains the local stub 127.0.0.53 as the only DNS server and a list of search domains. This is the recommended mode of operation that propagates the systemd-resolved managed configuration to all clients.
# ls -al resolv.conf
lrwxrwxrwx 1 root root 37 aug 13 07:27 resolv.conf -> /run/systemd/resolve/stub-resolv.conf
# cat /run/systemd/resolve/stub-resolv.conf
nameserver 127.0.0.53
options edns0 trust-ad
search .
Automatically
systemd-resolved will work out of the box with a network manager using /etc/resolv.conf. No particular configuration is required since systemd-resolved will be detected by following the /etc/resolv.conf symlink.
Manually
The resolver can be configured by editing /etc/systemd/resolved.conf and/or drop-in .conf files in /etc/systemd/resolved.conf.d/