RESOLVED.CONF(5) resolved.conf RESOLVED.CONF(5) resolved.conf, resolved.conf.d - /etc/systemd/resolved.conf /run/systemd/resolved.conf /usr/local/lib/systemd/resolved.conf /usr/lib/systemd/resolved.conf /etc/systemd/resolved.conf.d/*.conf /run/systemd/resolved.conf.d/*.conf /usr/local/lib/systemd/resolved.conf.d/*.conf /usr/lib/systemd/resolved.conf.d/*.conf DNS LLMNR. . : /etc/systemd/ /run/systemd/ /usr/local/lib/systemd/ [1] /usr/lib/systemd/. . (drop-ins) . ( /etc/ /usr/) . /usr/lib/systemd/*.conf.d/ /usr/local/lib/systemd/*.conf.d/ /etc/systemd/*.conf.d/. . *.conf.d/ . . (drop-ins) /usr/. /etc/ . . . . . 10-40 /usr/ 60-90 /etc/ /run/ . /dev/null /etc/ . [Resolve]: DNS= IPv4 IPv6 DNS . ":" "%" (SNI) "#". IPv6 . "111.222.333.444:9953%ifname#example.com" IPv4 "[1111:2222::3333]:9953%ifname#example.com" IPv6. DNS DNS DNS systemd-networkd.service(8) . DNS /etc/resolv.conf . . 213. FallbackDNS= IPv4 IPv6 DNS . DNS= . DNS systemd-networkd.service(8) DNS= /etc/resolv.conf. DNS . DNS . 216. Domains= "~" . . "~" ( ) (FQDNs). " " . /etc/resolv.conf search . "~" " ". ( "~") DNS . DNS . DNS= ( ) DHCP. DNS . "~." ( "~" "." DNS DNS) DNS . " " systemd-resolved.service(8) . MulticastDNS "local" DNS . DNS IANA MulticastDNS . DNS MulticastDNS. 229. LLMNR= "resolve". (RFC 4795[2]) . LLMNR. . "resolve" . systemd-networkd.service(8) LLMNR . LLMNR . 216. MulticastDNS= "resolve". DNS (RFC 6762[3]) . Multicast DNS. . "resolve" . systemd-networkd.service(8) Multicast DNS . Multicast DNS . 234. DNSSEC= "allow-downgrade". DNS DNSSEC ( LLMNR Multicast DNS). . DNS DNSSEC. DNS DNSSEC . "allow-downgrade" DNSSEC DNSSEC DNSSEC . DNSSEC "" DNSSEC DNS DNSSEC . DNS DNSSEC. DNSSEC DNS DNS. DNSSEC " " . dnssec-trust-anchors.d(5). . DNSSEC . DNSSEC= . DNSSEC= "allow-downgrade" DNSSEC . DNS DNSSEC ( DNS DNS DNSSEC ). DNS . DNSSEC= DNS DNSSEC . DNSSEC= "allow-downgrade". DNSSEC systemd-networkd.service(8) DNSSEC . DNS ( ) DNSSEC . DNS . DNS DNSSEC ( ) ( ) . "allow-downgrade" DNS (TLDs) DNS . . "no". 229. DNSOverTLS= "opportunistic". . DNS DNS-over-TLS . DNS= "address#server_name" (SNI) TLS. IP . DNS DNS-over-TLS DNS. "opportunistic" DNS DNS-over-TLS. DNS TLS DNS-over-TLS. DNS-over-TLS "" DNS-over-TLS . DNS UDP. DNS-over-TLS DNS. "opportunistic" " ". DNSOverTLS= systemd-networkd.service(8) DNSOverTLS= . DNS ( ) DNSOverTLS= . DNS . "no". 239. Cache= "no-negative". "yes" () . DNSSEC. "no-negative" . DNS . CacheFromLocalhost= . 231. CacheFromLocalhost= . "no" () IP ( 127.0.0.1 ::1) . 248. DNSStubListener= "udp" "tcp". "udp" DNS UDP 127.0.0.53 127.0.0.54 53. "tcp" TCP . "yes" () UDP TCP. "no" . DNS (stub resolver) 127.0.0.53 LLMNR/MulticastDNS. DNS 127.0.0.54 "" DNS DNS DNSSEC LLMNR/MulticastDNS. ( DNS-over-TLS .) DNS . 232. RefuseRecordTypes= DNS . . . . : RefuseRecordTypes=AAAA SRV TXT AAAA ( SRV TXT .) IPv6 "sysctl -w net.ipv6.conf.all.disable_ipv6=1". 258. DNSStubListenerExtra= IPv4 IPv6 . ("udp" "tcp") ":". UDP TCP. ":". IPv6 . 53. DNS stub DNSStubListener= . . . . : DNSStubListenerExtra=192.168.10.10 DNSStubListenerExtra=2001:db8:0:f102::10 DNSStubListenerExtra=192.168.10.11:9953 DNSStubListenerExtra=[2001:db8:0:f102::11]:9953 DNSStubListenerExtra=tcp:192.168.10.12 DNSStubListenerExtra=udp:2001:db8:0:f102::12 DNSStubListenerExtra=tcp:192.168.10.13:9953 DNSStubListenerExtra=udp:[2001:db8:0:f102::13]:9953 247. ReadEtcHosts= . "yes" () systemd-resolved /etc/hosts DNS. 240. ResolveUnicastSingleLabel= . false () systemd-resolved A AAAA DNS . ( Domains= ) LLMNR /etc/hosts. true DNS . DNS . IAB[4] . 246. StaleRetentionSec= DNS (TTL). . DNS TTL . DNS . systemd-resolved(8) DNS DNS . NXDOMAIN . DNS. systemd-resolved DNS . . 254. systemd(1), systemd-resolved.service(8), systemd-networkd.service(8), dnssec-trust-anchors.d(5), resolv.conf(5) 1. . /usr/local/ . 2. RFC 4795 https://tools.ietf.org/html/rfc4795 3. RFC 6762 https://tools.ietf.org/html/rfc6762 4. IAB https://www.iab.org/documents/correspondence-reports-documents/2013-2/iab-statement-dotless-domains-considered-harmful/ 3 . . : . systemd 260.2 RESOLVED.CONF(5)