# dnsblog(8postfix) - man - phpMan

[DNSBLOG(8postfix)](https://www.chedong.com/phpMan.php/man/DNSBLOG/8postfix/markdown)                                                                  [DNSBLOG(8postfix)](https://www.chedong.com/phpMan.php/man/DNSBLOG/8postfix/markdown)



## NAME
       dnsblog - Postfix DNS allow/denylist logger

## SYNOPSIS
       **dnsblog** [generic Postfix daemon options]

## DESCRIPTION
       The  [**dnsblog**(8)](https://www.chedong.com/phpMan.php/man/dnsblog/8/markdown) server implements an ad-hoc DNS allow/denylist lookup service. This may even‐
       tually be replaced by an UDP client that is built directly into the [**postscreen**(8)](https://www.chedong.com/phpMan.php/man/postscreen/8/markdown) server.

## PROTOCOL
       With each connection, the [**dnsblog**(8)](https://www.chedong.com/phpMan.php/man/dnsblog/8/markdown) server receives a DNS allow/denylist domain name, an  IP
       address, and an ID.  If the IP address is listed under the DNS allow/denylist, the [**dnsblog**(8)](https://www.chedong.com/phpMan.php/man/dnsblog/8/markdown)
       server logs the match and replies with the query arguments plus an address list with the  re‐
       sulting  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)](https://www.chedong.com/phpMan.php/man/dnsblog/8/markdown)
       server closes the connection.

## DIAGNOSTICS
       Problems and transactions are logged to [**syslogd**(8)](https://www.chedong.com/phpMan.php/man/syslogd/8/markdown) or [**postlogd**(8)](https://www.chedong.com/phpMan.php/man/postlogd/8/markdown).

## CONFIGURATION PARAMETERS
       Changes to **main.cf** are picked up automatically, as [**dnsblog**(8)](https://www.chedong.com/phpMan.php/man/dnsblog/8/markdown) processes run for only  a  lim‐
       ited amount of time. Use the command "**postfix** **reload**" to speed up a change.

       The  text below provides only a parameter summary. See [**postconf**(5)](https://www.chedong.com/phpMan.php/man/postconf/5/markdown) for more details including
       examples.

       **config**___**directory** **(see** **'postconf** **-d'** **output)**
              The default location of the Postfix main.cf and master.cf configuration files.

       **daemon**___**timeout** **(18000s)**
              How much time a Postfix daemon process may take to handle a request before it is  ter‐
              minated by a built-in watchdog timer.

       **postscreen**___**dnsbl**___**sites** **(empty)**
              Optional list of DNS allow/denylist 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  exam‐
              ple, "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)](https://www.chedong.com/phpMan.php/man/smtpd/8/markdown), Postfix SMTP server
       [postconf(5)](https://www.chedong.com/phpMan.php/man/postconf/5/markdown), configuration parameters
       [postlogd(8)](https://www.chedong.com/phpMan.php/man/postlogd/8/markdown), Postfix logging
       [syslogd(8)](https://www.chedong.com/phpMan.php/man/syslogd/8/markdown), 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



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