SHOREWALL6-INTERFAC(5)

NAME
interfaces - shorewall6 interfaces file

SYNOPSIS

/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.

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:

        #ZONE   INTERFACE       BROADCAST
        loc     eth1            -
        loc     eth2            -

INTERFACE - interface[:port]
    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. 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, ...

    Care must be exercised when using wildcards where there is another zone that uses a matching specific interface. See shorewall6-nesting[2](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.

UNICAST - -
    Enter '-' in this column. It is here for compatibility between Shorewall6 and Shorewall.

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.

    blacklist
        Check packets arriving on this interface against the shorewall6-blacklist[3](5) file.

    bridge
        Designates the interface as a bridge. Beginning with Shorewall 4.4.7, setting this option also sets routeback.

    forward[={0|1}]
        Sets the /proc/sys/net/ipv6/conf/interface/forwarding option to the specified value. If no value is supplied, then 1 is assumed.

    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).

    optional
        When optional is specified for an interface, shorewall6 will be silent when:

            • 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.

        physical=name
            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.

            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
            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.

        sourceroute[={0|1}]
            If this option is not specified for an interface, then source-routed packets will not be accepted from that interface (sets /proc/sys/net/ipv6/conf/interface/accept_source_route to 1). Only set this option 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 changes; 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.

        tcpflags
            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.

        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.

        wait=seconds
            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:

        #ZONE   INTERFACE UNICAST        OPTIONS
        net     eth0      -
        loc     eth1      -
        dmz     eth2      -

Example 4 (Shorewall 4.4.9 and later):
    You have a bridge with no IP address and you want to allow traffic through the bridge.

        #ZONE   INTERFACE BROADCAST        OPTIONS
        -       br0       -                routeback

FILES

/etc/shorewall6/interfaces

SEE ALSO

shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5), shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-maclist(5), shorewall6-params(5), shorewall6-policy(5), shorewall6-providers(5), shorewall6-route_rules(5), shorewall6-routestopped(5), shorewall6-rules(5), shorewall6.conf(5), shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-tcrules(5), shorewall6-tos(5), shorewall6-tunnels(5), shorewall6-zones(5)

NOTES

1.  shorewall6-hosts
    http://www.shorewall.net/manpages6/shorewall6-hosts.html

2.  shorewall6-nesting
    http://www.shorewall.net/manpages6/shorewall6-nesting.html

3.  shorewall6-blacklist
    http://www.shorewall.net/manpages6/shorewall6-blacklist.html