    DNSBLOG(8)                                                          DNSBLOG(8)

    NAME
           dnsblog - Postfix DNS white/blacklist logger

    SYNOPSIS
           dnsblog [generic Postfix daemon options]

    DESCRIPTION
           The  dnsblog(8)  server implements an ad-hoc DNS white/blacklist lookup
           service. This may eventually be replaced by an UDP client that is built
           directly into the postscreen(8) server.

    PROTOCOL
           With each connection, the dnsblog(8) server receives a DNS white/black-
           list domain name, an IP address, and an  ID.   If  the  IP  address  is
           listed  under  the  DNS white/blacklist, the dnsblog(8) server logs the
           match and replies with the query arguments plus an  address  list  with
           the resulting IP addresses, separated by whitespace, and the reply TTL.
           Otherwise it replies with the query arguments  plus  an  empty  address
           list  and the reply TTL; the reply TTL is -1 if there is no reply, or a
           negative reply that contains no SOA record.   Finally,  the  dnsblog(8)
           server closes the connection.

    DIAGNOSTICS
           Problems and transactions are logged to syslogd(8) or postlogd(8).

    CONFIGURATION PARAMETERS
           Changes to main.cf are picked up automatically, as dnsblog(8) processes
           run for only a limited amount of time. Use the command "postfix reload"
           to speed up a change.

           The  text  below provides only a parameter summary. See postconf(5) for
           more details including examples.

           config_directory (see 'postconf -d' output)
                  The default location of the Postfix main.cf and  master.cf  con-
                  figuration files.

           daemon_timeout (18000s)
                  How  much  time  a  Postfix  daemon process may take to handle a
                  request before it is terminated by a built-in watchdog timer.

           postscreen_dnsbl_sites (empty)
                  Optional list of DNS white/blacklist domains, filters and weight
                  factors.

           ipc_timeout (3600s)
                  The  time  limit  for  sending  or receiving information over an
                  internal communication channel.

           process_id (read-only)
                  The process ID of a Postfix command or daemon process.

           process_name (read-only)
                  The process name of a Postfix command or daemon process.

           queue_directory (see 'postconf -d' output)
                  The location of the Postfix top-level queue directory.

           syslog_facility (mail)
                  The syslog facility of Postfix logging.

           syslog_name (see 'postconf -d' output)
                  A prefix that  is  prepended  to  the  process  name  in  syslog
                  records, so that, for example, "smtpd" becomes "prefix/smtpd".

           Available in Postfix 3.3 and later:

           service_name (read-only)
                  The master.cf service name of a Postfix daemon process.

    SEE ALSO
           smtpd(8), Postfix SMTP server
           postconf(5), configuration parameters
           postlogd(8), Postfix logging
           syslogd(8), system logging

    LICENSE
           The Secure Mailer license must be distributed with this software.

    HISTORY
           This service was introduced with Postfix version 2.8.

    AUTHOR(S)
           Wietse Venema
           IBM T.J. Watson Research
           P.O. Box 704
           Yorktown Heights, NY 10598, USA

           Wietse Venema
           Google, Inc.
           111 8th Avenue
           New York, NY 10011, USA

                                                                        DNSBLOG(8)