SHOREWALL6-INTERFAC(5) | Configuration Files | SHOREWALL6-INTERFAC(5) |
NAME¶
interfaces - shorewall6 interfaces fileSYNOPSIS¶
/etc/shorewall6/interfaces
DESCRIPTION¶
The interfaces file serves to define the firewall's network interfaces to shorewall6. The order of entries in this file is not significant in determining zone composition. Beginning with Shorewall 4.5.3, the interfaces file supports two different formats: FORMAT 1 (default - deprecated)There is a ANYCAST column which provides compatibility
with older versions of Shorewall..
FORMAT 2
The BROADCAST column is omitted.
The format is specified by a line as follows:
[?]FORMAT {1|2}
The optional '?' was introduced in Shorewall 4.5.11 and ?FORMAT is the preferred
form; the form without the '?' is deprecated.
The columns in the file are as follows.
ZONE - zone-name
Zone for this interface. Must match the name of a zone
declared in /etc/shorewall6/zones. You may not list the firewall zone in this
column.
If the interface serves multiple zones that will be defined in the
shorewall6-hosts[1](5) file, you should place "-" in this
column.
If there are multiple interfaces to the same zone, you must list them in
separate entries.
Example:
Beginning with Shorewall 4.5.17, if you specify a zone for the 'lo' interface,
then that zone must be defined as type local in
shorewall6-zones[2](5).
INTERFACE - interface[:port]
#ZONE INTERFACE BROADCAST loc eth1 - loc eth2 -
Logical name of interface. Each interface may be listed
only once in this file. You may NOT specify the name of a "virtual"
interface (e.g., eth0:0) here; see
http://www.shorewall.net/FAQ.htm#faq18[3]. If the physical
option is not specified, then the logical name is also the name of the actual
interface.
You may use wildcards here by specifying a prefix followed by the plus sign
("+"). For example, if you want to make an entry that applies to all
PPP interfaces, use 'ppp+'; that would match ppp0, ppp1, ppp2, ...Please note
that the '+' means ' one or more additional characters' so 'ppp' does
not match 'ppp+'.
Care must be exercised when using wildcards where there is another zone that
uses a matching specific interface. See shorewall6-nesting[4](5) for a
discussion of this problem.
Shorewall6 allows '+' as an interface name.
There is no need to define the loopback interface (lo) in this file.
If a port is given, then the interface must have been defined
previously with the bridge option. The OPTIONS column must be empty
when a port is given.
ANYCAST - -
Enter '-' in this column. It is here for
compatibility between Shorewall6 and Shorewall and is omitted if FORMAT is
2.
OPTIONS (Optional) - [option[,option]...]
A comma-separated list of options from the following
list. The order in which you list the options is not significant but the list
should have no embedded white-space.
accept_ra[={0|1|2}]
Added in Shorewall 4.5.16. Values are:
0
blacklist
Do not accept Router Advertisements.
1
Accept Route Advertisements if forwarding is
disabled.
2
Overrule forwarding behavior. Accept Route Advertisements
even if forwarding is enabled.
If the option is specified without a value, then the value 1 is assumed.Check packets arriving on this interface against the
shorewall6-blacklist[5](5) file.
Beginning with Shorewall 4.4.13:
bridge
•If a zone is given in the ZONES column,
then the behavior is as if blacklist had been specified in the
IN_OPTIONS column of shorewall6-zones[2](5).
•Otherwise, the option is ignored with a warning:
WARNING: The 'blacklist' option is ignored on multi-zone
interfaces
Designates the interface as a bridge. Beginning with
Shorewall 4.4.7, setting this option also sets routeback.
destonly
Added in Shorewall 4.5.17. Causes the compiler to omit
rules to handle traffic from this interface.
dhcp
Specify this option when any of the following are true:
forward[={0|1}]
1.the interface gets its IP address via DHCP
2.the interface is used by a DHCP server running on the
firewall
3.the interface has a static IP but is on a LAN segment
with lots of DHCP clients.
4.the interface is a simple bridge[6] with a DHCP
server on one port and DHCP clients on another port.
Note
If you use Shorewall-perl for firewall/bridging[7], then you need to
include DHCP-specific rules in shorewall-rules[8](8). DHCP uses UDP
ports 546 and 547.
This option allows DHCP datagrams to enter and leave the interface.Sets the /proc/sys/net/ipv6/conf/interface/forwarding
option to the specified value. If no value is supplied, then 1 is
assumed.
ignore[=1]
When specified, causes the generated script to ignore
up/down events from Shorewall-init for this device. Additionally, the option
exempts the interface from hairpin filtering. When '=1' is omitted, the ZONE
column must contain '-' and ignore must be the only OPTION.
Beginning with Shorewall 4.5.5, may be specified as ' ignore=1' which
only causes the generated script to ignore up/down events from Shorewall-init;
hairpin filtering is still applied. In this case, the above restrictions on
the ZONE and OPTIONS columns are lifted.
mss=number
Causes forwarded TCP SYN packets entering or leaving on
this interface to have their MSS field set to the specified
number.
nets=(net[,...])
Limit the zone named in the ZONE column to only the
listed networks. If you specify this option, be sure to include the link-local
network (ff80::/10).
nets=dynamic
Added in Shorewall 4.4.21. Defines the zone as dynamic.
Requires ipset match support in your iptables and kernel. See
http://www.shorewall.net/Dynamic.html[9] for further information.
optional
When optional is specified for an interface,
shorewall6 will be silent when:
physical=name
•a /proc/sys/net/ipv6/conf/ entry for the
interface cannot be modified.
•The first global IPv6 address of the interface
cannot be obtained.
This option may not be specified together with required.Added in Shorewall 4.4.4. When specified, the interface
or port name in the INTERFACE column is a logical name that refers to the name
given in this option. It is useful when you want to specify the same wildcard
port name on two or more bridges. See
http://www.shorewall.net/bridge-Shorewall-perl.html#Multiple[10].
If the interface name is a wildcard name (ends with '+'), then the
physical name must also end in '+'.
If physical is not specified, then it's value defaults to the
interface name.
required
Added in Shorewall 4.4.10. When specified, the firewall
will fail to start if the interface named in the INTERFACE column is not
usable. May not be specified together with optional.
routeback[={0|1}]
If specified, indicates that shorewall6 should include
rules that allow traffic arriving on this interface to be routed back out that
same interface. This option is also required when you have used a wildcard in
the INTERFACE column if you want to allow traffic between the interfaces that
match the wildcard.
If you specify this option, then you should also specify rpfilter (see
below) if you are running Shorewall 4.5.7 or later; otherwise, you should
specify sfilter (see below).
Beginning with Shorewall 4.5.18, you may specify this option to explicitly reset
(e.g., routeback=0). This can be used to override Shorewall's default
setting for bridge devices which is routeback=1.
rpfilter
Added in Shorewall 4.5.7. This is an anti-spoofing
measure that requires the 'RPFilter Match' capability in your iptables and
kernel. It provides a more efficient alternative to the sfilter option
below.
sourceroute[={0|1}]
If this option is not specified for an interface, then
source-routed packets will not be accepted from that interface unless
explicitly enabled via sysconf. Only set this option to 1 (enable source
routing) if you know what you are doing. This might represent a security risk
and is not usually needed.
Only those interfaces with the sourceroute option will have their setting
changed; the value assigned to the setting will be the value specified (if
any) or 1 if no value is given.
Note
This option does not work with a wild-card interface name (e.g., eth0.+)
in the INTERFACE column.
sfilter=(net[,...])
Added in Shorewall 4.4.20. At this writing (spring 2011),
Linux does not support reverse path filtering (RFC3704) for IPv6. In its
absence, sfilter may be used as an anti-spoofing measure.
This option should be used on bridges or other interfaces with the
routeback option. On these interfaces, sfilter should list those
local networks that are connected to the firewall through other
interfaces.
tcpflags[={0|1}]
Packets arriving on this interface are checked for
certain illegal combinations of TCP flags. Packets found to have such a
combination of flags are handled according to the setting of
TCP_FLAGS_DISPOSITION after having been logged according to the setting of
TCP_FLAGS_LOG_LEVEL.
Beginning with Shorewall 4.6.0, tcpflags=1 is the default. To disable this
option, specify tcpflags=0.
proxyndp[={0|1}]
Sets /proc/sys/net/ipv6/conf/interface/proxy_ndp.
Note: This option does not work with a wild-card interface name
(e.g., eth0.+) in the INTERFACE column.
Only those interfaces with the proxyndp option will have their setting
changed; the value assigned to the setting will be the value specified (if
any) or 1 if no value is given.
unmanaged
Added in Shorewall 4.5.18. Causes all traffic between the
firewall and hosts on the interface to be accepted. When this option is given:
wait=seconds
•The ZONE column must contain '-'.
•Only the following other options are allowed with
unmanaged:
accept_ra
forward
ignore
optional
physical
sourceroute
proxyndp
Added in Shorewall 4.4.10. Causes the generated script to
wait up to seconds seconds for the interface to become usable before
applying the required or optional options.
EXAMPLE¶
Example 1:Suppose you have eth0 connected to a DSL modem and eth1
connected to your local network You have a DMZ using eth2.
Your entries for this setup would look like:
Example 4 (Shorewall 4.4.9 and later):
FORMAT 2 #ZONE INTERFACE OPTIONS net eth0 - loc eth1 - dmz eth2 -
You have a bridge with no IP address and you want to
allow traffic through the bridge.
FORMAT 2 #ZONE INTERFACE OPTIONS - br0 routeback
FILES¶
/etc/shorewall6/interfacesSEE ALSO¶
http://www.shorewall.net/configuration_file_basics.htm#Pairs[11] shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5), shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-maclist(5), shorewall6-netmap(5),shorewall6-params(5), shorewall6-policy(5), shorewall6-providers(5), shorewall6-rtrules(5), shorewall6-routestopped(5), shorewall6-rules(5), shorewall6.conf(5), shorewall6-secmarks(5), shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-mangle(5), shorewall6-tos(5), shorewall6-tunnels(5), shorewall6-zones(5)NOTES¶
- 1.
- shorewall6-hosts
- 2.
- shorewall6-zones
- 4.
- shorewall6-nesting
- 5.
- shorewall6-blacklist
- 6.
- simple bridge
- 7.
- Shorewall-perl for firewall/bridging
- 8.
- shorewall-rules
10/19/2014 | Configuration Files |