ubuntu如何使用域名解析

sudo apt update
sudo apt install bind9

sudo nano /etc/bind/named.conf.options

options {
    directory "/var/cache/bind";

    recursion yes;
    allow-query { any; };

    forwarders {
        8.8.8.8;  # Google DNS
        8.8.4.4;  # Google DNS
    };
};

sudo nano /etc/bind/db.example.com

$TTL    604800
@       IN      SOA     ns1.example.com. admin.example.com. (
                              2         ; Serial
                         604800         ; Refresh
                          86400         ; Retry
                        2419200         ; Expire
                         604800 )       ; Negative Cache TTL

;
@       IN      NS      ns1.example.com.
@       IN      A       192.0.2.1
www     IN      A       192.0.2.2

sudo systemctl start bind9
sudo systemctl enable bind9

dig @localhost www.example.com

; <<>> DiG 9.11.3-1ubuntu1.13-Ubuntu <<>> @localhost www.example.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 52740
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

;; QUESTION SECTION:
;www.example.com.           IN      A

;; ANSWER SECTION:
www.example.com.        604800  IN      A       192.0.2.2

;; AUTHORITY SECTION:
example.com.            604800  IN      NS      ns1.example.com.

;; ADDITIONAL SECTION:
ns1.example.com.         604800  IN      A       192.0.2.1

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Thu Oct 21 12:34:56 UTC 2021
;; MSG SIZE  rcvd: 90