SYNOPSIS

       postmap -q "string" cidr:/etc/postfix/filename

       postmap -q - cidr:/etc/postfix/filename <inputfile

DESCRIPTION

       The  Postfix  mail  system  uses optional access control tables.  These
       tables are usually in dbm or db format.  Alternatively, access  control
       tables  can be specified in CIDR (Classless Inter-Domain Routing) form.

       To find out what types of lookup tables your  Postfix  system  supports
       use the postconf -m command.

       To test lookup tables, use the postmap command as described in the SYN-
       OPSIS above.

TABLE FORMAT

       The general form of a Postfix CIDR table is:

       network_address/network_mask     result
              When a search string matches the specified  network  block,  use
              the corresponding result value. Specify 0.0.0.0/0 to match every
              address.

       network_address     result
              When a search string matches the specified network address,  use
              the corresponding result value.

       blank lines and comments
              Empty  lines and whitespace-only lines are ignored, as are lines
              whose first non-whitespace character is a `#'.

       multi-line text
              A logical line starts with  non-whitespace  text.  A  line  that
              starts with whitespace continues a logical line.

SEARCH ORDER

       Patterns  are  applied  in the order as specified in the table, until a
       pattern is found that matches the search string.

EXAMPLE SMTPD ACCESS MAP

       /etc/postfix/main.cf:
           smtpd_client_restrictions = ... cidr:/etc/postfix/client.cidr ...

       /etc/postfix/client.cidr:
           # Rule order matters. Put more specific whitelist entries
           # before more general blacklist entries.
           192.168.1.1             OK
           192.168.0.0/16          REJECT

SEE ALSO

       postmap(1), Postfix lookup table manager
       1525 Budapest, Hungary

       Adopted and adapted by:
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA



                                                                 CIDR_TABLE(5)