The two main logging options are channel and category, which configure where logs go, and what information gets logged, respectively.

If no logging options are configured the default configuration is:

logging {
     category default { default_syslog; default_debug; };
     category unmatched { null; };
};

We need to configure a channel to specify which file to send the messages to, and a category.

In this example, the category will log all queries.

Edit /etc/bind/named.conf.local and add the following:

/etc/bind/named.conf.local

logging {
    channel query.log {
        file "/var/log/named/query.log";
        severity debug 3;
    };
    category queries { query.log; };
};

Since the named daemon runs as the bind user the /var/log/named directory must be created and the ownership changed:

sudo mkdir /var/log/named
sudo chown bind:bind /var/log/named

Restart BIND9 for the changes to take effect:

sudo systemctl restart bind9.service

You should see the file /var/log/named/query.log fill with query information.

This is a simple example of the BIND9 logging options.

For coverage of advanced options see More Information.