named.rev(4tcp)
named.rev --
IN-ADDR.ARPA database file
Synopsis
$INCLUDE named.soa [comment]
[$ORIGIN domain [comment]]
[$TTL default_ttl [comment]]
[$GENERATE range lhs type rhs [comment]
...
name [ttl] class PTR real_name.
Description
The named.rev file
contains the zone database for the IN-ADDR.ARPA domain.
The actual filename is arbitrary; it is normally specified in
named.boot as the source file for each
IN-ADDR.ARPA domain.
Pointer records (PTR)
are needed to convert IP addresses to
hostnames, for example using
gethostbyaddr(3N).
See
named.hosts(4tcp)
for a description of these records.
The entries are:
name-
The IP address of the host in reverse order.
Only enough octets need to be specified
to make the name unique within the zone.
real_name-
The name of the host to which the index points.
There should be an entry for each host listed in the
named.hosts(4tcp)
file.
A trailing ``.'' prevents DNS from appending the current
$ORIGIN.
See
named.local(4tcp)
for a description of the PTR and A records that are
needed for the local loopback interface, localhost.
Generated resource records
The $GENERATE statement is used to generate a set of resource records
that only differ from each other by the value of the iterator. This mechanism
can be used to generate the records that are required to support reverse
delegations for subnets with a mask length greater than 24 bits (described
in RFC 2317).
range-
Defines the iteration values using the format
start-stop[/step]
with 1 as the default step value. stop must be
greater than start, and all must be positive integers.
lhs-
Evaluates to a domain name for the record. Single ``$'' characters
are replaced by the value of the iterator. A ``$'' itself may be
represented by ``$$''. If lhs is not absolute (that is,
it does not end in a ``.''), the current $ORIGIN is appended
to the name.
type-
One of CNAME, NS or PTR.
rhs-
Evaluates to a domain name in a similar way to lhs.
Files
/etc/inet/named.d/db.reverse_address-
suggested name for reverse hosts database file
References
gethostbyaddr(3N),
named(1Mtcp),
named.boot(4tcp),
named.hosts(4tcp),
named.local(4tcp),
named.soa(4tcp),
root.cache(4tcp)
RFC 1035,
RFC 2317
Examples
$INCLUDE named.soa
1.130 IN PTR host1.company.COM.
2.130 IN PTR host2.company.COM.
3.130 IN PTR host3.company.COM.
The following entries perform classless IN-ADDR.ARPA delegation
as described in RFC 2317:
$ORIGIN 0.0.192.IN-ADDR-ARPA.
$GENERATE 1-2 0 NS SERVER$.MYDOM.COM.
$GENERATE 1-127 $ CNAME $.0
This is equivalent to:
0.0.0.192.IN-ADDR-ARPA. NS SERVER1.MYDOM.COM.
0.0.0.192.IN-ADDR-ARPA. NS SERVER2.MYDOM.COM.
1.0.0.192.IN-ADDR-ARPA. CNAME 1.0.0.0.192.IN-ADDR-ARPA.
2.0.0.192.IN-ADDR-ARPA. CNAME 2.0.0.0.192.IN-ADDR-ARPA.
...
127.0.0.192.IN-ADDR-ARPA. CNAME 127.0.0.0.192.IN-ADDR-ARPA.
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004