4.2 RR Format

Names in the database must start on the first position. If the first character in the line is a space, the name from the previous line is used. A file consists of RRs (Resource Records), listed in Table 2.1.

4.2.1 SOA Records

The Start Of Authority (SOA) record determines the name server that is an authoritative source of information for the particular domain. There is always only one SOA record in the file, and it is placed at the beginning of the file of authoritative resource records.

Example 1: The record for the server of the company.com zone:

@ IN SOA ns.company.com .hostmaster.company.com (
1 ;Serial
86400 ;Refresh after 24 hours
600 ;Retry after 5 min.
120960 ;Expire after 2 weeks
86400) ;Minimum TTL of 1 day

The explanation of the code is as follows:

• The name must start immediately on the first position of the line and must have a dot at the end. It specifies the name of a zone. Usually @ is used instead of the name of the zone, which means the name of the zone should...