1DNSBLOG(8) System Manager's Manual DNSBLOG(8)
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6 dnsblog - Postfix DNS allow/denylist logger
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9 dnsblog [generic Postfix daemon options]
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12 The dnsblog(8) server implements an ad-hoc DNS allow/denylist lookup
13 service. This may eventually be replaced by an UDP client that is built
14 directly into the postscreen(8) server.
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17 With each connection, the dnsblog(8) server receives a DNS al‐
18 low/denylist domain name, an IP address, and an ID. If the IP address
19 is listed under the DNS allow/denylist, the dnsblog(8) server logs the
20 match and replies with the query arguments plus an address list with
21 the resulting IP addresses, separated by whitespace, and the reply TTL.
22 Otherwise it replies with the query arguments plus an empty address
23 list and the reply TTL; the reply TTL is -1 if there is no reply, or a
24 negative reply that contains no SOA record. Finally, the dnsblog(8)
25 server closes the connection.
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28 Problems and transactions are logged to syslogd(8) or postlogd(8).
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31 Changes to main.cf are picked up automatically, as dnsblog(8) processes
32 run for only a limited amount of time. Use the command "postfix reload"
33 to speed up a change.
34 The text below provides only a parameter summary. See postconf(5) for
36 more details including examples.
37 config_directory (see 'postconf -d' output)
39 The default location of the Postfix main.cf and master.cf con‐
40 figuration files.
41 daemon_timeout (18000s)
43 How much time a Postfix daemon process may take to handle a re‐
44 quest before it is terminated by a built-in watchdog timer.
45 postscreen_dnsbl_sites (empty)
47 Optional list of DNS allow/denylist domains, filters and weight
48 factors.
49 ipc_timeout (3600s)
51 The time limit for sending or receiving information over an in‐
52 ternal communication channel.
53 process_id (read-only)
55 The process ID of a Postfix command or daemon process.
56 process_name (read-only)
58 The process name of a Postfix command or daemon process.
59 queue_directory (see 'postconf -d' output)
61 The location of the Postfix top-level queue directory.
62 syslog_facility (mail)
64 The syslog facility of Postfix logging.
65 syslog_name (see 'postconf -d' output)
67 A prefix that is prepended to the process name in syslog
68 records, so that, for example, "smtpd" becomes "prefix/smtpd".
69 Available in Postfix 3.3 and later:
71 service_name (read-only)
73 The master.cf service name of a Postfix daemon process.
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76 smtpd(8), Postfix SMTP server
77 postconf(5), configuration parameters
78 postlogd(8), Postfix logging
79 syslogd(8), system logging
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82 The Secure Mailer license must be distributed with this software.
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85 This service was introduced with Postfix version 2.8.
86
88 Wietse Venema
89 IBM T.J. Watson Research
90 P.O. Box 704
91 Yorktown Heights, NY 10598, USA
92 Wietse Venema
94 Google, Inc.
95 111 8th Avenue
96 New York, NY 10011, USA
97 DNSBLOG(8)