DNS , . . , DNS , DNS .

DNS- ?
DNS- DNS , , . , DNS , .
. , - . DNS , . , MSNBC 100 . , 10 , .
DNS , . , - , DNS . .
, system-resolved
DNSSEC DNSoverTLS DoT. .
?
systemd-resolved
. systemd
. systemd
, Linux , systemd-resolved
, . .
systemd-resolved
DNS-, . , DNS .
systemd-resolved?
, Ubuntu 19.04, systemd-resolved
.
systemd-resolved
, - . , NetworkManager, .
systemd-resolved
:
$ resolvectl status
, systemd-resolved
:
$ resolvectl status Failed to get global data: Unit dbus-org.freedesktop.resolve1.service not found.
, - , systemd-resolved
:
Global LLMNR setting: yes MulticastDNS setting: yes DNSOverTLS setting: opportunistic DNSSEC setting: allow-downgrade DNSSEC supported: no Current DNS Server: 1.1.1.1 DNS Servers: 1.1.1.1 1.0.0.1
systemd-resolved
systemd-resolved
, systemd
. . :
$ sudo systemctl start systemd-resolved.service
, .
$ sudo systemctl enable systemd-resolved.service
DNS , . , , DNSSEC DoT:
Google Public DNS
8.8.8.8 8.8.4.4
Cloudflare Public DNS
1.1.1.1 1.0.0.1
systemd-resolved
:
$ sudo nano /etc/systemd/resolved.conf
, :
#DNS=
. Cloudflare Public DNS:
DNS=1.1.1.1 1.0.0.1
systemd-resolved
:
$ sudo systemctl restart systemd-resolved.service
, systemd-resolved
DNS , .
systemd-resolved
DNS . . , . , /etc/resolv.conf
.
/etc/resolv.conf
IP , . .
, /run/systemd/resolve/stub-resolv.conf
. /etc/resolv.conf
systemd-resolved
.
, /etc/resolv.conf
. /etc/resolv.conf
, . , , /etc/resolv.conf
IP 127.0.0.53
.
. /etc/resolv.conf
. ,
$ sudo mv /etc/resolv.conf /etc/resolv.conf.original
:
$ sudo ln -s /run/systemd/resolve/stub-resolv.conf /etc/resolv.conf
systemd-resolved
:
$ sudo systemctl restart systemd-resolved.service
, , system-resolved
. /etc/resolv.conf
:
$ sudo nano /etc/resolv.conf
, nameserver
:
nameserver 127.0.0.53
. , DNS 127.0.0.53
.
systemd-resolved
, DNS . systemd-resolved
, .
systemd-resolved
, . :
$ sudo systemctl edit systemd-resolved.service
:
[Service] Environment=SYSTEMD_LOG_LEVEL=debug
systemd-resolved
. journald
:
$ sudo journalctl -f -u systemd-resolved
, Using DNS server
, DNS . DNS Cloudflare
Using DNS server 1.1.1.1 for transaction 19995.
Cache miss
, :
Cache miss for example.com IN SOA
Positive cache
, systemd-resolved
:
Positive cache hit for example.com IN A
, . :
$ sudo systemctl edit systemd-resolved.service
.
DNS
systemd-resolved DNS , DNSSEC DNSoverTLS. , DNS (DNSSEC) (DoT).
system-resolved
:
$ sudo nano /etc/systemd/resolved.conf
:
DNSSEC=allow-downgrade DNSOverTLS=opportunistic
systemd-resolved
.
$ sudo systemctl restart systemd-resolved.service
DNS DNS . DNS Google CloudFlare .
DNS . , DNS .