cidr_table(5)

1CIDR_TABLE(5)                 File Formats Manual                CIDR_TABLE(5)
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NAME

6       cidr_table - format of Postfix CIDR tables
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SYNOPSIS

9       postmap -q "string" cidr:/etc/postfix/filename
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11       postmap -q - cidr:/etc/postfix/filename <inputfile
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DESCRIPTION

14       The  Postfix mail system uses optional lookup tables.  These tables are
15       usually in dbm or db format.  Alternatively, lookup tables can be spec‐
16       ified in CIDR (Classless Inter-Domain Routing) form. In this case, each
17       input is compared against a list of patterns. When a  match  is  found,
18       the corresponding result is returned and the search is terminated.
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20       To  find  out  what types of lookup tables your Postfix system supports
21       use the "postconf -m" command.
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23       To test lookup tables, use the "postmap -q" command as described in the
24       SYNOPSIS above.
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TABLE FORMAT

27       The general form of a Postfix CIDR table is:
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29       network_address/network_mask     result
30              When  a  search  string matches the specified network block, use
31              the corresponding result value. Specify 0.0.0.0/0 to match every
32              IPv4 address, and ::/0 to match every IPv6 address.
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34              An  IPv4  network  address  is a sequence of four decimal octets
35              separated by ".", and an IPv6 network address is a  sequence  of
36              three to eight hexadecimal octet pairs separated by ":".
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38              Before  comparisons  are made, lookup keys and table entries are
39              converted from string to binary. Therefore table entries will be
40              matched regardless of redundant zero characters.
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42              Note:  address  information may be enclosed inside "[]" but this
43              form is not required.
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45              IPv6 support is available in Postfix 2.2 and later.
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47       network_address     result
48              When a search string matches the specified network address,  use
49              the corresponding result value.
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51       blank lines and comments
52              Empty  lines and whitespace-only lines are ignored, as are lines
53              whose first non-whitespace character is a `#'.
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55       multi-line text
56              A logical line starts with  non-whitespace  text.  A  line  that
57              starts with whitespace continues a logical line.
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TABLE SEARCH ORDER

60       Patterns  are  applied  in the order as specified in the table, until a
61       pattern is found that matches the search string.
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EXAMPLE SMTPD ACCESS MAP

64       /etc/postfix/main.cf:
65           smtpd_client_restrictions = ... cidr:/etc/postfix/client.cidr ...
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67       /etc/postfix/client.cidr:
68           # Rule order matters. Put more specific whitelist entries
69           # before more general blacklist entries.
70           192.168.1.1             OK
71           192.168.0.0/16          REJECT
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README FILES

79       Use "postconf readme_directory" or "postconf html_directory" to  locate
80       this information.
81       DATABASE_README, Postfix lookup table overview
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HISTORY

84       CIDR table support was introduced with Postfix version 2.1.
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AUTHOR(S)

87       The CIDR table lookup code was originally written by:
88       Jozsef Kadlecsik
89       KFKI Research Institute for Particle and Nuclear Physics
90       POB. 49
91       1525 Budapest, Hungary
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93       Adopted and adapted by:
94       Wietse Venema
95       IBM T.J. Watson Research
96       P.O. Box 704
97       Yorktown Heights, NY 10598, USA
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