shorewall.conf.5

sharewall is very good

.\"     Title: shorewall.conf
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.74.0 <http://docbook.sf.net/>
.\"      Date: 03/19/2009
.\"    Manual: [FIXME: manual]
.\"    Source: [FIXME: source]
.\"  Language: English
.\"
.TH "SHOREWALL\&.CONF" "5" "03/19/2009" "[FIXME: source]" "[FIXME: manual]"
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.\" * MAIN CONTENT STARTS HERE *
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.SH "Name"
shorewall.conf \- Shorewall global configuration file
.SH "Synopsis"
.fam C
.HP \w'\fB/etc/shorewall/shorewall\&.conf\fR\ 'u
\fB/etc/shorewall/shorewall\&.conf\fR
.fam
.SH "Description"
.PP
This file sets options that apply to Shorewall as a whole\&.
.PP
The file consists of Shell comments (lines beginning with \'#\'), blank lines and assignment statements (\fIvariable\fR=\fIvalue\fR)\&.
.SH "OPTIONS"
.PP
Many options have as their value a
\fIlog\-level\fR\&. Log levels are a method of describing to syslog (8) the importance of a message and a number of parameters in this file have log levels as their value\&.
.PP
These levels are defined by syslog and are used to determine the destination of the messages through entries in /etc/syslog\&.conf (5)\&. The syslog documentation refers to these as "priorities"; Netfilter calls them "levels" and Shorewall also uses that term\&.
.PP
Valid levels are:
.sp
.if n \{\
.RS 4
.\}
.fam C
.ps -1
.nf
.BB lightgray
       7       debug
       6       info
       5       notice
       4       warning
       3       err
       2       crit
       1       alert
       0       emerg
.EB lightgray
.fi
.fam
.ps +1
.if n \{\
.RE
.\}
.PP
For most Shorewall logging, a level of 6 (info) is appropriate\&. Shorewall log messages are generated by NetFilter and are logged using facility \'kern\' and the level that you specifify\&. If you are unsure of the level to choose, 6 (info) is a safe bet\&. You may specify levels by name or by number\&.
.PP
If you have built your kernel with ULOG and/or NFLOG target support, you may also specify a log level of ULOG and/or NFLOG (must be all caps)\&. Rather than log its messages to syslogd, Shorewall will direct netfilter to log the messages via the ULOG or NFLOG target which will send them to a process called \'ulogd\'\&. ulogd is available with most Linux distributions (although it probably isn\'t installed by default)\&. Ulogd is also available from
\m[blue]\fBhttp://www\&.netfilter\&.org/projects/ulogd/index\&.html\fR\m[]
and can be configured to log all Shorewall message to their own log file
.PP
The following options may be set in shorewall\&.conf\&.
.PP
\fBACCEPT_DEFAULT=\fR{\fIaction\fR|\fImacro\fR|\fBnone\fR}
.RS 4
.RE
.PP
\fBDROP_DEFAULT=\fR{\fIaction\fR|\fImacro\fR|\fBnone\fR}
.RS 4
.RE
.PP
\fBREJECT_DEFAULT=\fR{\fIaction\fR|\fImacro\fR|\fBnone\fR}
.RS 4
.RE
.PP
\fBQUEUE_DEFAULT=\fR{\fIaction\fR|\fImacro\fR|\fBnone\fR}
.RS 4
.RE
.PP
\fBNFQUEUE_DEFAULT=\fR{\fIaction\fR|\fImacro\fR|\fBnone\fR} (Shorewall\-perl 4\&.0\&.3 and later)
.RS 4
In earlier Shorewall versions, a "default action" for DROP and REJECT policies was specified in the file /usr/share/shorewall/actions\&.std\&.
.sp
To allow for default rules to be applied when USE_ACTIONS=No, the DROP_DEFAULT, REJECT_DEFAULT, ACCEPT_DEFAULT, QUEUE_DEFAULT and NFQUEUE_DEFAULT options have been added\&.
.sp
DROP_DEFAULT describes the rules to be applied before a connection request is dropped by a DROP policy; REJECT_DEFAULT describes the rules to be applied if a connection request is rejected by a REJECT policy\&. The other three are similar for ACCEPT, QUEUE and NFQUEUE policies\&.
.sp
The value applied to these may be:
.RS 4
a) The name of an
            \fIaction\fR\&.
.RE
.RS 4
b) The name of a \fImacro\fR
            (Shorewall\-shell only)
.RE
.RS 4
c) \fBNone\fR or \fBnone\fR
.RE
The default values are:
.RS 4
DROP_DEFAULT="Drop"
.RE
.RS 4
REJECT_DEFAULT="Reject"
.RE
.RS 4
ACCEPT_DEFAULT="none"
.RE
.RS 4
QUEUE_DEFAULT="none"
.RE
.RS 4
NFQUEUE_DEFAULT="None"
.RE
If USE_ACTIONS=Yes, then these values refer to action\&.Drop and action\&.Reject respectively\&. If USE_ACTIONS=No, then these values refer to macro\&.Drop and macro\&.Reject\&.
.sp
If you set the value of either option to "None" then no default action will be used and the default action or macro must be specified in
\m[blue]\fBshorewall\-policy\fR\m[]\&\s-2\u[1]\d\s+2(5)\&.
.RE
.PP
\fBADD_IP_ALIASES=\fR[\fBYes\fR|\fBNo\fR]
.RS 4
This parameter determines whether Shorewall automatically adds the external address(es) in
\m[blue]\fBshorewall\-nat\fR\m[]\&\s-2\u[2]\d\s+2(5)\&. If the variable is set to
\fBYes\fR
or
\fByes\fR
then Shorewall automatically adds these aliases\&. If it is set to
\fBNo\fR
or
\fBno\fR, you must add these aliases yourself using your distribution\'s network configuration tools\&.
.sp
If this variable is not set or is given an empty value (ADD_IP_ALIASES="") then ADD_IP_ALIASES=Yes is assumed\&.
.if n \{\
.sp
.\}
.RS 4
.BM yellow
.it 1 an-trap
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.ps +1
\fBWarning\fR
.ps -1
.br
Addresses added by ADD_IP_ALIASES=Yes are deleted and re\-added during shorewall restart\&. As a consequence, connections using those addresses may be severed\&.
.sp .5v
.EM yellow
.RE
.RE
.PP
\fBADD_SNAT_ALIASES=\fR[\fBYes\fR|\fBNo\fR]
.RS 4
This parameter determines whether Shorewall automatically adds the SNAT ADDRESS in
\m[blue]\fBshorewall\-masq\fR\m[]\&\s-2\u[3]\d\s+2(5)\&. If the variable is set to
\fBYes\fR
or
\fByes\fR
then Shorewall automatically adds these addresses\&. If it is set to
\fBNo\fR
or
\fBno\fR, you must add these addresses yourself using your distribution\'s network configuration tools\&.
.sp
If this variable is not set or is given an empty value (ADD_SNAT_ALIASES="") then ADD_SNAT_ALIASES=No is assumed\&.
.if n \{\
.sp
.\}
.RS 4
.BM yellow
.it 1 an-trap
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.ps +1
\fBWarning\fR
.ps -1
.br
Addresses added by ADD_SNAT_ALIASES=Yes are deleted and re\-added during shorewall restart\&. As a consequence, connections using those addresses may be severed\&.
.sp .5v
.EM yellow
.RE
.RE
.PP
\fBADMINISABSENTMINDED=\fR[\fBYes\fR|\fBNo\fR]
.RS 4
The value of this variable affects Shorewall\'s stopped state\&. When ADMINISABSENTMINDED=No, only traffic to/from those addresses listed in
\m[blue]\fBshorewall\-routestopped\fR\m[]\&\s-2\u[4]\d\s+2(5) is accepted when Shorewall is stopped\&. When ADMINISABSENTMINDED=Yes, in addition to traffic to/from addresses in
\m[blue]\fBshorewall\-routestopped\fR\m[]\&\s-2\u[4]\d\s+2(5), connections that were active when Shorewall stopped continue to work and all new connections from the firewall system itself are allowed\&. If this variable is not set or is given the empty value then ADMINISABSENTMINDED=No is assumed\&.
.RE
.PP
\fBAUTO_COMMENT=\fR[\fBYes\fR|\fBNo\fR]
.RS 4
Added in Shorewall\-perl 4\&.1\&.5\&. If set, if there is not a current comment when a macro is invoked, the behavior is as if the first line of the macro file was "COMMENT <macro name>"\&. The AUTO_COMMENT option has a default value of \'Yes\'\&.
.RE
.PP
\fBBIGDPORTLISTS=\fR[\fBYes\fR|\fBNo\fR]
.RS 4
Setting this option to \'Yes\' allows you to include arbitrarily long destination port lists in all configuration files\&.
.RE
.PP
\fBBLACKLIST_DISPOSITION=\fR[\fBDROP\fR|\fBREJECT\fR]
.RS 4
This parameter determines the disposition of packets from blacklisted hosts\&. It may have the value DROP if the packets are to be dropped or REJECT if the packets are to be replied with an ICMP port unreachable reply or a TCP RST (tcp only)\&. If you do not assign a value or if you assign an empty value then DROP is assumed\&.
.RE
.PP
\fBBLACKLIST_LOGLEVEL=\fR[\fIlog\-level\fR]
.RS 4
This parameter determines if packets from blacklisted hosts are logged and it determines the syslog level that they are to be logged at\&. Its value is a syslog level (Example: BLACKLIST_LOGLEVEL=debug)\&. If you do not assign a value or if you assign an empty value then packets from blacklisted hosts are not logged\&.
.RE
.PP
\fBBLACKLISTNEWONLY=\fR{\fBYes\fR|\fBNo\fR}
.RS 4
When set to
\fBYes\fR
or
\fByes\fR, blacklists are only consulted for new connections\&. When set to
\fBNo\fR
or
\fBno\fR, blacklists are consulted for every packet (will slow down your firewall noticably if you have large blacklists)\&. If the BLACKLISTNEWONLY option is not set or is set to the empty value then BLACKLISTNEWONLY=No is assumed\&.
.if n \{\
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\fBNote\fR
.ps -1
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BLACKLISTNEWONLY=No is incompatible with FASTACCEPT=Yes\&.
.sp .5v
.EM yellow
.RE
.RE
.PP