Adding Similar Records

2.19.1 Problem

You want to add a number of records that differ only slightly.

2.19.2 Solution

Use the $GENERATE control statement to specify a template that the name server will use to generate a group of similar records. For example, to add a series of PTR records that differ only by a single digit, you could use this $GENERATE control statement:

$GENERATE 11-20 $.0.168.192.in-addr.arpa. PTR dhcp-$.foo.example.

Your BIND name server will read the range (11-20) and it will also read the template ($.0.168.192.in-addr.arpa. PTR dhcp-$.foo.example.) from the $GENERATE control statement. Then it will iterate through the range, replacing any dollar signs ("$") in the template with the current value, creating 10 PTR records:

11.0.168.192.in-addr.arpa. PTR dhcp-11.foo.example. 12.0.168.192.in-addr.arpa. PTR dhcp-12.foo.example. 13.0.168.192.in-addr.arpa. PTR dhcp-13.foo.example. ... 20.0.168.192.in-addr.arpa. PTR dhcp-20.foo.example.

2.19.3 Discussion

$GENERATE supports a limited set of record types: A, AAAA, CNAME, DNAME, NS and PTR. Also, the template can't contain a TTL or a class field, just a type.

If you want to get fancy, you can also step through the range using the range format start-stop/range. So 0-100/2 would count from 0 to 100 by twos.

BIND 8.2 introduced $GENERATE to the world. BIND 9.1.0 introduced $GENERATE to the BIND 9 releases.

Note that, unlike the $INCLUDE and $ORIGIN control statements, $GENERATE is only supported by BIND name servers; you can't use it in a zone data file on a Microsoft DNS Server, for example.

2.19.4 See Also

"Subnetting on a Non-Octet Boundary" in Chapter 9 of DNS and BIND, and Section 6.3.6 of the BIND 9 Administrator Reference Manual.