Provided by:
shorewall-common_4.0.12-1_all 
NAME
shorewall.conf - Shorewall global configuration file
SYNOPSIS
/etc/shorewall/shorewall.conf
DESCRIPTION
This file sets options that apply to Shorewall as a whole.
The file consists of Shell comments (lines beginning with ’#’), blank
lines and assignment statements (variable=value).
OPTIONS
Many options have as their value a log-level. 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.
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.
Valid levels are:
7 debug
6 info
5 notice
4 warning
3 err
2 crit
1 alert
0 emerg
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.
If you have built your kernel with ULOG target support, you may also
specify a log level of ULOG (must be all caps). Rather than log its
messages to syslogd, Shorewall will direct netfilter to log the
messages via the ULOG 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
〈http://www.netfilter.org/projects/ulogd/index.html〉 and can be
configured to log all Shorewall message to their own log file
The following options may be set in shorewall.conf.
ACCEPT_DEFAULT={action|macro|none}
DROP_DEFAULT={action|macro|none}
REJECT_DEFAULT={action|macro|none}
QUEUE_DEFAULT={action|macro|none}
NFQUEUE_DEFAULT={action|macro|none} (Shorewall-perl 4.0.3 and later)
In earlier Shorewall versions, a "default action" for DROP and
REJECT policies was specified in the file
/usr/share/shorewall/actions.std.
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.
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.
The value applied to these may be:
a) The name of an action.
b) The name of a macro (Shorewall-shell only)
c) None or none
The default values are:
DROP_DEFAULT="Drop"
REJECT_DEFAULT="Reject"
ACCEPT_DEFAULT="none"
QUEUE_DEFAULT="none"
NFQUEUE_DEFAULT="None"
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.
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 shorewall-policy 〈shorewall-policy.html〉 (5).
ADD_IP_ALIASES=[Yes|No]
This parameter determines whether Shorewall automatically adds
the external address(es) in shorewall-nat 〈shorewall-nat.html〉
(5). If the variable is set to Yes or yes then Shorewall
automatically adds these aliases. If it is set to No or no, you
must add these aliases yourself using your distribution’s
network configuration tools.
If this variable is not set or is given an empty value
(ADD_IP_ALIASES="") then ADD_IP_ALIASES=Yes is assumed.
Warning
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.
ADD_SNAT_ALIASES=[Yes|No]
This parameter determines whether Shorewall automatically adds
the SNAT ADDRESS in shorewall-masq 〈shorewall-masq.html〉 (5). If
the variable is set to Yes or yes then Shorewall automatically
adds these addresses. If it is set to No or no, you must add
these addresses yourself using your distribution’s network
configuration tools.
If this variable is not set or is given an empty value
(ADD_SNAT_ALIASES="") then ADD_SNAT_ALIASES=No is assumed.
Warning
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.
ADMINISABSENTMINDED=[Yes|No]
The value of this variable affects Shorewall’s stopped state.
When ADMINISABSENTMINDED=No, only traffic to/from those
addresses listed in shorewall-routestopped
〈shorewall-routestopped.html〉 (5) is accepted when Shorewall is
stopped. When ADMINISABSENTMINDED=Yes, in addition to traffic
to/from addresses in shorewall-routestopped
〈shorewall-routestopped.html〉 (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.
BIGDPORTLISTS=[Yes|No]
Setting this option to ’Yes’ allows you to include arbitrarily
long destination port lists in all configuration files.
BLACKLIST_DISPOSITION=[DROP|REJECT]
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.
BLACKLIST_LOGLEVEL=[log-level]
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.
BLACKLISTNEWONLY={Yes|No}
When set to Yes or yes, blacklists are only consulted for new
connections. When set to No or no, 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.
Note
BLACKLISTNEWONLY=No is incompatible with FASTACCEPT=Yes.
BRIDGING={Yes|No}
When set to Yes or yes, enables Shorewall Bridging support.
Note
BRIDGING=Yes may not work properly with Linux kernel 2.6.20 or
later and is not supported by Shorewall-perl.
CLAMPMSS=[Yes|No|value]
This parameter enables the TCP Clamp MSS to PMTU feature of
Netfilter and is usually required when your internet connection
is through PPPoE or PPTP. If set to Yes or yes, the feature is
enabled. If left blank or set to No or no, the feature is not
enabled.
Important: This option requires CONFIG_IP_NF_TARGET_TCPMSS in
your kernel.
You may also set CLAMPMSS to a numeric value (e.g.,
CLAMPMSS=1400). This will set the MSS field in TCP SYN packets
going through the firewall to the value that you specify.
CLEAR_TC=[Yes|No]
If this option is set to No then Shorewall won’t clear the
current traffic control rules during [re]start. This setting is
intended for use by people that prefer to configure traffic
shaping when the network interfaces come up rather than when the
firewall is started. If that is what you want to do, set
TC_ENABLED=Yes and CLEAR_TC=No and do not supply an
/etc/shorewall/tcstart file. That way, your traffic shaping
rules can still use the “fwmark” classifier based on packet
marking defined in shorewall-tcrules 〈shorewall-tcrules.html〉
(5). If not specified, CLEAR_TC=Yes is assumed.
CONFIG_PATH=[directory[:directory]...]
Specifies where configuration files other than shorewall.conf
may be found. CONFIG_PATH is specifies as a list of directory
names separated by colons (":"). When looking for a
configuration file other than shorewall.conf:
· If the command is "try" or if a "<configuration directory>"
was specified in the command (e.g., shorewall check ./gateway)
then the directory given in the command is searched first.
· Next, each directory in the CONFIG_PATH setting is searched in
sequence.
If CONFIG_PATH is not given or if it is set to the empty value
then the contents of /usr/share/shorewall/configpath are used.
As released from shorewall.net, that file sets the CONFIG_PATH
to /etc/shorewall:/usr/share/shorewall but your particular
distribution may set it differently. See the output of shorewall
show config for the default on your system.
Note that the setting in /usr/share/shorewall/configpath is
always used to locate shorewall.conf.
DELAYBLACKLISTLOAD={Yes|No}
Users with a large static black list ( shorewall-blacklist
〈shorewall-blacklist.html〉 (5)) may want to set the
DELAYBLACKLISTLOAD option to Yes. When DELAYBLACKLISTLOAD=Yes,
Shorewall will enable new connections before loading the
blacklist rules. While this may allow connections from
blacklisted hosts to slip by during construction of the
blacklist, it can substantially reduce the time that all new
connections are disabled during shorewall [re]start.
Note
DELAYBLACKLISTLOAD=Yes is not supported by Shorewall-perl.
DELETE_THEN_ADD={Yes|No}
Added in Shorewall 4.0.4. If set to Yes (the default value),
entries in the /etc/shorewall/route_stopped files cause an ’ip
rule del’ command to be generated in addition to an ’ip rule
add’ command. Setting this option to No, causes the ’ip rule
del’ command to be omitted.
DETECT_DNAT_IPADDRS=[Yes|No]
If set to Yes or yes, Shorewall will detect the first IP address
of the interface to the source zone and will include this
address in DNAT rules as the original destination IP address. If
set to No or no, Shorewall will not detect this address and any
destination IP address will match the DNAT rule. If not
specified or empty, “DETECT_DNAT_IPADDRS=Yes” is assumed.
DONT_LOAD=[module[,module]...]
Added in Shorewall-4.0.6. Causes Shorewall to not load the
listed modules.
DYNAMIC_ZONES={Yes|No}
When set to Yes or yes, enables dynamic zones. DYNAMIC_ZONES=Yes
is not allowed in configurations that will run under Shorewall
Lite.
EXPAND_POLICIES={Yes|No}
Normally, when the SOURCE or DEST columns in shorewall-policy(5)
contains ’all’, a single policy chain is created and the policy
is enforced in that chain. For example, if the policy entry is
#SOURCE DEST POLICY LOG
# LEVEL
net all DROP info
then the chain name is ’net2all’ which is also the chain named
in Shorewall log messages generated as a result of the policy.
If EXPAND_POLICIES=Yes, then Shorewall-perl will create a
separate chain for each pair of zones covered by the policy.
This makes the resulting log messages easier to interpret since
the chain in the messages will have a name of the form ’a2b’
where ’a’ is the SOURCE zone and ’b’ is the DEST zone.
EXPORTPARAMS={Yes|No}
It is quite difficult to code a ’params’ file that assigns other
than constant values such that it works correctly with Shorewall
Lite. The EXPORTPARAMS option works around this problem. When
EXPORTPARAMS=No, the ’params’ file is not copied to the compiler
output.
With EXPORTPARAMS=No, if you need to set environmental variables
on the firewall system for use by your extension scripts, then
do so in the init extension script.
The default is EXPORTPARAMS=Yes
FASTACCEPT={Yes|No}
Normally, Shorewall defers accepting ESTABLISHED/RELATED packets
until these packets reach the chain in which the original
connection was accepted. So for packets going from the ’loc’
zone to the ’net’ zone, ESTABLISHED/RELATED packets are ACCEPTED
in the ’loc2net’ chain.
If you set FASTACCEPT=Yes, then ESTABLISHED/RELEATED packets are
accepted early in the INPUT, FORWARD and OUTPUT chains. If you
set FASTACCEPT=Yes then you may not include rules in the
ESTABLISHED or RELATED sections of shorewall-rules
〈shorewall-rules.html〉 (5).
Note
FASTACCEPT=Yes is incompatible with BLACKLISTNEWONLY=No.
HIGH_ROUTE_MARKS={Yes|No}
Prior to version 3.2.0, it was not possible to use connection
marking in shorewall-tcrules 〈shorewall-tcrules.html〉 (5) if you
have a multi-ISP configuration that uses the track option.
Beginning with release 3.2.0, you may now set
HIGH_ROUTE_MARKS=Yes in to effectively divide the packet mark
and connection mark into two 8-byte mark fields.
When you do this:
1. The MARK field in the providers file must have a value that
is less than 65536 and that is a multiple of 256 (using hex
representation, the values are 0x0100-0xFF00 with the low-
order 8 bits being zero).
2. You may only set those mark values in the PREROUTING chain.
3. Marks used for traffic shaping must still be in the range of
1-255 and may still not be set in the PREROUTING chain.
4. When you SAVE or RESTORE in tcrules, only the TC mark value
is saved or restored. Shorewall handles saving and restoring
the routing (provider) marks.
IMPLICIT_CONTINUE={Yes|No}
When this option is set to Yes, it causes subzones to be treated
differently with respect to policies.
Subzones are defined by following their name with ":" and a list
of parent zones (in shorewall-zones 〈shorewall-zones.html〉 (5)).
Normally, you want to have a set of special rules for the
subzone and if a connection doesn’t match any of those subzone-
specific rules then you want the parent zone rules and policies
to be applied; see shorewall-nesting 〈shorewall-nesting.html〉
(5). With IMPLICIT_CONTINUE=Yes, that happens automatically.
If IMPLICIT_CONTINUE=No or if IMPLICIT_CONTINUE is not set, then
subzones are not subject to this special treatment. With
IMPLICIT_CONTINUE=Yes, an implicit CONTINUE policy may be
overridden by including an explicit policy (one that does not
specify "all" in either the SOURCE or the DEST columns).
IP_FORWARDING=[On|Off|Keep]
This parameter determines whether Shorewall enables or disables
IPV4 Packet Forwarding (/proc/sys/net/ipv4/ip_forward).
Possible values are:
On or on
packet forwarding will be enabled.
Off or off
packet forwarding will be disabled.
Keep or keep
Shorewall will neither enable nor disable packet
forwarding.
If this variable is not set or is given an empty value
(IP_FORWARD="") then IP_FORWARD=On is assumed.
IPSECFILE={zones|ipsec}
This should be set to zones for all new Shorewall installations.
IPSECFILE=ipsec is only used for compatibility with pre-
Shorewall-3.0 configurations.
IPTABLES=[pathname]
This parameter names the iptables executable to be used by
Shorewall. If not specified or if specified as a null value,
then the iptables executable located using the PATH option is
used.
Regardless of how the IPTABLES utility is located (specified via
IPTABLES= or located via PATH), Shorewall uses the iptables-
restore and iptables-save utilities from that same directory.
KEEP_RT_TABLES={Yes|No}
Added in Shorewall 4.0.3. When set to Yes, this option prevents
scripts generated by Shorewall-perl from altering the
/etc/iproute2/rt_tables database when there are entries in
/etc/shorewall/providers. If you set this option to Yes while
Shorewall (Shorewall-lite) is running, you should remove the
file /var/lib/shorewall/rt_tables
(/var/lib/shorewall-lite/rt_tables) before your next stop,
refresh, restore on restart command.
The default is KEEP_RT_TABLES=No.
LOG_MARTIANS=[Yes|No|Keep]
If set to Yes or yes, sets
/proc/sys/net/ipv4/conf/all/log_martians and
/proc/sys/net/ipv4/conf/default/log_martians to 1. Default is No
which sets both of the above to zero. If you do not enable
martian logging for all interfaces, you may still enable it for
individual interfaces using the logmartians interface option in
shorewall-interfaces 〈shorewall-interfaces.html〉 (5).
The value Keep is only allowed under Shorewall-perl. It causes
Shorewall to ignore the option. If the option is set to Yes,
then martians are logged on all interfaces. If the option is set
to No, then martian logging is disabled on all interfaces except
those specified in shorewall-interfaces
〈shorewall-interfaces.html〉 (5).
LOGALLNEW=[log-level]
This option is intended for use as a debugging aid. When set to
a log level, this option causes Shorewall to generate a logging
rule as the first rule in each builtin chain.
· The table name is used as the chain name in the log prefix.
· The chain name is used as the target in the log prefix.
For example, using the default LOGFORMAT, the log prefix for
logging from the nat table’s PREROUTING chain is:
Shorewall:nat:PREROUTING
Important
To help insure that all packets in the NEW state are
logged, rate limiting (LOGBURST and LOGLIMIT) should be
disabled when using LOGALLNEW. Use LOGALLNEW at your own
risk; it may cause high CPU and disk utilization and you
may not be able to control your firewall after you enable
this option.
Caution
Do not use this option if the resulting log messages will
be sent to another system.
LOGFILE=[pathname]
This parameter tells the /sbin/shorewall program where to look
for Shorewall messages when processing the dump, logwatch, show
log, and hits commands. If not assigned or if assigned an empty
value, /var/log/messages is assumed.
LOGFORMAT=["formattemplate"]
The value of this variable generate the --log-prefix setting for
Shorewall logging rules. It contains a “printf” formatting
template which accepts three arguments (the chain name, logging
rule number (optional) and the disposition). To use LOGFORMAT
with fireparse, set it as:
LOGFORMAT="fp=%s:%d a=%s "
If the LOGFORMAT value contains the substring “%d” then the
logging rule number is calculated and formatted in that
position; if that substring is not included then the rule number
is not included. If not supplied or supplied as empty
(LOGFORMAT="") then “Shorewall:%s:%s:” is assumed.
LOGBURST=[burst]
LOGRATE=[rate/{minute|second}]
These parameters set the match rate and initial burst size for
logged packets. Please see iptables(8) for a description of the
behavior of these parameters (the iptables option --limit is set
by LOGRATE and --limit-burst is set by LOGBURST). If both
parameters are set empty, no rate-limiting will occur.
Example:
LOGRATE=10/minute
LOGBURST=5
For each logging rule, the first time the rule is reached, the
packet will be logged; in fact, since the burst is 5, the first
five packets will be logged. After this, it will be 6 seconds (1
minute divided by the rate of 10) before a message will be
logged from the rule, regardless of how many packets reach it.
Also, every 6 seconds which passes without matching a packet,
one of the bursts will be regained; if no packets hit the rule
for 30 seconds, the burst will be fully recharged; back where we
started.
LOGTAGONLY=[Yes|No]
Using the default LOGFORMAT, chain names may not exceed 11
characters or truncation of the log prefix may occur. Longer
chain names may be used with log tags if you set LOGTAGONLY=Yes.
With LOGTAGONLY=Yes, if a log tag is specified then the tag is
included in the log prefix in place of the chain name.
MACLIST_DISPOSITION=[ACCEPT|DROP|REJECT]
Determines the disposition of connections requests that fail MAC
Verification and must have the value ACCEPT (accept the
connection request anyway), REJECT (reject the connection
request) or DROP (ignore the connection request). If not set or
if set to the empty value (e.g., MACLIST_DISPOSITION="") then
MACLIST_DISPOSITION=REJECT is assumed.
MACLIST_LOG_LEVEL=[log-level]
Determines the syslog level for logging connection requests that
fail MAC Verification. The value must be a valid syslogd log
level. If you don’t want to log these connection requests, set
to the empty value (e.g., MACLIST_LOG_LEVEL="").
MACLIST_TABLE=[filter|mangle]
Normally, MAC verification occurs in the filter table (INPUT and
FORWARD) chains. When forwarding a packet from an interface with
MAC verification to a bridge interface, that doesn’t work.
This problem can be worked around by setting
MACLIST_TABLE=mangle which will cause Mac verification to occur
out of the PREROUTING chain. Because REJECT isn’t available in
that environment, you may not specify MACLIST_DISPOSITION=REJECT
with MACLIST_TABLE=mangle.
MACLIST_TTL=[number]
The performance of configurations with a large numbers of
entries in shorewall-maclist 〈shorewall-maclist.html〉 (5) can be
improved by setting the MACLIST_TTL variable in shorewall.conf
〈shorewall.conf.html〉 (5).
If your iptables and kernel support the "Recent Match" (see the
output of "shorewall check" near the top), you can cache the
results of a ’maclist’ file lookup and thus reduce the overhead
associated with MAC Verification.
When a new connection arrives from a ’maclist’ interface, the
packet passes through then list of entries for that interface in
shorewall-maclist 〈shorewall-maclist.html〉 (5). If there is a
match then the source IP address is added to the ’Recent’ set
for that interface. Subsequent connection attempts from that IP
address occurring within $MACLIST_TTL seconds will be accepted
without having to scan all of the entries. After $MACLIST_TTL
from the first accepted connection request from an IP address,
the next connection request from that IP address will be checked
against the entire list.
If MACLIST_TTL is not specified or is specified as empty (e.g,
MACLIST_TTL="" or is specified as zero then ’maclist’ lookups
will not be cached).
MAPOLDACTIONS=[Yes|No]
Previously, Shorewall included a large number of standard
actions (AllowPing, AllowFTP, ...). These have been replaced
with parameterized macros. For compatibility, Shorewall can map
the old names into invocations of the new macros if you set
MAPOLDACTIONS=Yes. If this option is not set or is set to the
empty value (MAPOLDACTIONS="") then MAPOLDACTIONS=Yes is
assumed.
Note
MAPOLDACTIONS=Yes is not supported by Shorewall-perl. With
Shorewall-perl, if MAPOLDACTIONS is not set or is set to the
ampty value then MAPOLDACTIONS=No is assumed.
MARK_IN_FORWARD_CHAIN=[Yes|No]
If your kernel has a FORWARD chain in the mangle table, you may
set MARK_IN_FORWARD_CHAIN=Yes to cause the marking specified in
the tcrules file to occur in that chain rather than in the
PREROUTING chain. This permits you to mark inbound traffic based
on its destination address when DNAT is in use. To determine if
your kernel has a FORWARD chain in the mangle table, use the
/sbin/shorewall show mangle command; if a FORWARD chain is
displayed then your kernel will support this option. If this
option is not specified or if it is given the empty value (e.g.,
MARK_IN_FORWARD_CHAIN="") then MARK_IN_FORWARD_CHAIN=No is
assumed.
MODULE_SUFFIX=["extension ..."]
The value of this option determines the possible file extensions
of kernel modules. The default value is "o gz ko o.gz".
MODULESDIR=[pathname[:pathname]...]
This parameter specifies the directory/directories where your
kernel netfilter modules may be found. If you leave the variable
empty, Shorewall will supply the value "/lib/modules/‘uname
-r‘/kernel/net/ipv4/netfilter" in versions of Shorewall prior to
3.2.4 and "/lib/modules/‘uname
-r‘/kernel/net/ipv4/netfilter:/lib/modules/‘uname
-r‘/kernel/net/ipv4/netfilter" in later versions.
MULTICAST=[Yes|No]
This option will normally be set to ’No’ (the default). It
should be set to ’Yes’ under the following circumstances:
1. You have an interface that has parallel zones defined via
/etc/shorewall/hosts.
2. You want to forward multicast packets to two or more of
those parallel zones.
In such cases, you will configure a destonly network on each zone
receiving multicasts.
The MULTICAST option is only recognized by Shorewall-perl and is
ignored by Shorewall-shell.
MUTEX_TIMEOUT=[seconds]
The value of this variable determines the number of seconds that
programs will wait for exclusive access to the Shorewall lock
file. After the number of seconds corresponding to the value of
this variable, programs will assume that the last program to
hold the lock died without releasing the lock.
If not set or set to the empty value, a value of 60 (60 seconds)
is assumed.
An appropriate value for this parameter would be twice the
length of time that it takes your firewall system to process a
shorewall restart command.
OPTIMIZE=[0|1]
Traditionally, Shorewall has created rules for the complete
matrix of host groups defined by the zones, interfaces
and hosts files 〈../ScalabilityAndPerformance.html〉 . Any
traffic that didn’t correspond to an element of that matrix was
rejected in one of the built-in chains. When the matrix is
sparse, this results in lots of largely useless rules.
These extra rules can be eliminated by setting OPTIMIZE=1.
The OPTIMIZE setting also controls the suppression of redundant
wildcard rules (those specifying "all" in the SOURCE or DEST
column). A wildcard rule is considered to be redundant when it
has the same ACTION and Log Level as the applicable policy.
PATH=pathname[:pathname]...
Determines the order in which Shorewall searches directories for
executable files.
PKTTYPE={Yes|No}
Normally Shorewall attempts to use the iptables packet type
match extension to determine broadcast and multicast packets.
1. This can cause a message to appear during shorewall start
(modprobe: cant locate module ipt_pkttype).
2. Some users have found problems with the packet match
extension with the result that their firewall log is flooded
with messages relating to broadcast packets.
If you are experiencing either of these problems, setting
PKTTYPE=No will prevent Shorewall from trying to use the packet
type match extension and to use IP address matching to determine
which packets are broadcasts or multicasts.
RCP_COMMAND="command"
RSH_COMMAND="command"
Eariler generations of Shorewall Lite required that remote root
login via ssh be enabled in order to use the load and reload
commands. Beginning with release 3.9.5, you may define an
alternative means for accessing the remote firewall system. In
that release, two new options were added to shorewall.conf:
RSH_COMMAND
RCP_COMMAND
The default values for these are as follows:
RSH_COMMAND: ssh ${root}@${system} ${command}
RCP_COMMAND: scp ${files} ${root}@${system}:${destination}
Shell variables that will be set when the commands are envoked
are as follows:
root - root user. Normally root but may be overridden using the
’-r’ option.
system - The name/IP address of the remote firewall system.
command - For RSH_COMMAND, the command to be executed on the
firewall system.
files - For RCP_COMMAND, a space-separated list of files to be
copied to the remote firewall system.
destination - The directory on the remote system that the files
are to be copied into.
RESTOREFILE=filename
Specifies the simple name of a file in /var/lib/shorewall to be
used as the default restore script in the shorewall save,
shorewall restore, shorewall forget and shorewall -f start
commands.
RETAIN_ALIASES={Yes|No}
During shorewall start, IP addresses to be added as a
consequence of ADD_IP_ALIASES=Yes and ADD_SNAT_ALIASES=Yes are
quietly deleted when shorewall-nat 〈shorewall-nat.html〉 (5) and
shorewall-masq 〈shorewall-masq.html〉 (5) are processed then are
re-added later. This is done to help ensure that the addresses
can be added with the specified labels but can have the
undesirable side effect of causing routes to be quietly deleted.
When RETAIN_ALIASES is set to Yes, existing addresses will not
be deleted. Regardless of the setting of RETAIN_ALIASES,
addresses added during shorewall start are still deleted at a
subsequent shorewall stop or shorewall restart.
RFC1918_LOG_LEVEL=[log-level]
This parameter determines the level at which packets logged
under the norfc1918 mechanism are logged. The value must be a
valid syslog level and if no level is given, then info is
assumed.
RFC1918_STRICT=[Yes|No]
Traditionally, the RETURN target in the ’rfc1918’ file has
caused norfc1918 processing to cease for a packet if the
packet’s source IP address matches the rule. Thus, if you have
this entry in shorewall-rfc1918 〈shorewall-rfc1918.html〉 (5):
#SUBNETS TARGET
192.168.1.0/24 RETURN
then traffic from 192.168.1.4 to 10.0.3.9 will be accepted even
though you also have:
#SUBNETS TARGET
10.0.0.0/8 logdrop
Setting RFC1918_STRICT=Yes in shorewall.conf will cause such
traffic to be logged and dropped since while the packet’s source
matches the RETURN rule, the packet’s destination matches the
’logdrop’ rule.
If not specified or specified as empty (e.g., RFC1918_STRICT="")
then RFC1918_STRICT=No is assumed.
Warning
RFC1918_STRICT=Yes requires that your kernel and iptables
support ’Connection Tracking’ match.
ROUTE_FILTER=[Yes|No|Keep]
If this parameter is given the value Yes or yes then route
filtering (anti-spoofing) is enabled on all network interfaces
which are brought up while Shorewall is in the started state.
The default value is no.
The value Keep is only allowed under Shorewall-perl. It causes
Shorewall to ignore the option. If the option is set to Yes,
then route filtering occurs on all interfaces. If the option is
set to No, then route filtering is disabled on all interfaces
except those specified in shorewall-interfaces
〈shorewall-interfaces.html〉 (5).
SAVE_IPSETS={Yes|No}
If SAVE_IPSETS=Yes, then the current contents of your ipsets
will be saved by the shorewall save command. Regardless of the
setting of SAVE_IPSETS, if saved ipset contents are available
then they will be restored by shorewall restore.
SHOREWALL_COMPILER={perl|shell}
Specifies the compiler to use to generate firewall scripts when
both compilers are installed. The value of this option can be
either perl or shell. If both compilers are installed and
SHOREWALL_SHELL is not set, then SHOREWALL_SHELL=shell is
assumed.
If you add ’SHOREWALL_COMPILER=perl’ to
/etc/shorewall/shorewall.conf then by default, the Shorewall-
perl compiler will be used on the system. If you add it to
shorewall.conf in a separate directory (such as a Shorewall-lite
export directory) then the Shorewall-perl compiler will only be
used when you compile from that directory.
If you only install one compiler, it is suggested that you do
not set SHOREWALL_COMPILER.
This setting may be overriden in those commands that invoke the
compiler by using the -C command option (see shorewall
〈shorewall.html〉 (8)).
SHOREWALL_SHELL=[pathname]
This option is used to specify the shell program to be used to
run the Shorewall compiler and to interpret the compiled script.
If not specified or specified as a null value, /bin/sh is
assumed. Using a light-weight shell such as ash or dash can
significantly improve performance.
SMURF_LOG_LEVEL=[log-level]
Specifies the logging level for smurf packets (see the nosmurfs
option in shorewall-interfaces 〈shorewall-interfaces.html〉 (5)).
If set to the empty value ( SMURF_LOG_LEVEL="" ) then smurfs are
not logged.
STARTUP_ENABLED={Yes|No}
Determines if Shorewall is allowed to start. As released from
shorewall.net, this option is set to No. When set to Yes or yes,
Shorewall may be started. Used as a guard against Shorewall
being accidentally started before it has been configured.
SUBSYSLOCK=[pathname]
This parameter should be set to the name of a file that the
firewall should create if it starts successfully and remove when
it stops. Creating and removing this file allows Shorewall to
work with your distribution’s initscripts. For RedHat, this
should be set to /var/lock/subsys/shorewall. For Debian, the
value is /var/state/shorewall and in LEAF it is
/var/run/shorwall.
TC_ENABLED=[Yes|No|Internal]
If you say Yes or yes here, Shorewall will use a script that you
supply to configure traffic shaping. The script must be named
’tcstart’ and must be placed in a directory on your CONFIG_PATH.
If you say No or no then traffic shaping is not enabled.
If you set TC_ENABLED=Internal or internal or leave the option
empty then Shorewall will use its builtin traffic shaper
(tc4shorewall written by Arne Bernin.
TC_EXPERT={Yes|No}
Normally, Shorewall tries to protect users from themselves by
preventing PREROUTING and OUTPUT tcrules from being applied to
packets that have been marked by the ’track’ option in
shorewall-providers 〈shorewall-providers.html〉 (5).
If you know what you are doing, you can set TC_EXPERT=Yes and
Shorewall will not include these cautionary checks.
TCP_FLAGS_DISPOSITION=[ACCEPT|DROP|REJECT]
Determines the disposition of TCP packets that fail the checks
enabled by the tcpflags interface option (see shorewall-
interfaces 〈shorewall-interfaces.html〉 (5)) and must have a
value of ACCEPT (accept the packet), REJECT (send an RST
response) or DROP (ignore the packet). If not set or if set to
the empty value (e.g., TCP_FLAGS_DISPOSITION="") then
TCP_FLAGS_DISPOSITION=DROP is assumed.
TCP_FLAGS_LOG_LEVEL=[log-level]
Determines the syslog level for logging packets that fail the
checks enabled by the tcpflags interface option. The value must
be a valid syslogd log level. If you don’t want to log these
packets, set to the empty value (e.g., TCP_FLAGS_LOG_LEVEL="").
USE_ACTIONS={Yes|No}
While Shorewall Actions can be very useful, they also require a
sizable amount of code to implement. By setting USE_ACTIONS=No,
embedded Shorewall installations can omit the large library
/usr/share/shorewall/lib.actions.
Note
USE_ACTIONS=No is not supported by Shorewall-perl.
VERBOSITY=[number]
Shorewall has traditionally been very noisy (produced lots of
output). You may set the default level of verbosity using the
VERBOSITY OPTION.
Values are:
0 — Silent. You may make it more verbose using the -v option
1 — Major progress messages displayed
2 — All progress messages displayed (pre Shorewall-3.2.0
behavior)
If not specified, then 2 is assumed.
FILES
/etc/shorewall/shorewall.conf
SEE ALSO
shorewall(8), shorewall-accounting(5), shorewall-actions(5), shorewall-
blacklist(5), shorewall-hosts(5), shorewall-interfaces(5), shorewall-
ipsec(5), shorewall-maclist(5), shorewall-masq(5), shorewall-nat(5),
shorewall-netmap(5), shorewall-params(5), shorewall-policy(5),
shorewall-providers(5), shorewall-proxyarp(5), shorewall-
route_rules(5), shorewall-routestopped(5), shorewall-rules(5),
shorewall-tcclasses(5), shorewall-tcdevices(5), shorewall-tcrules(5),
shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)
24 June 2008 shorewall.conf(5)