addresses — Specifying addresses within a Shorewall configuration
In both Shorewall and Shorewall6, there are two basic types of addresses:
This address type refers to a single host.
In IPv4, the format is i.j.k.l where i through l are decimal numbers between 1 and 255.
In IPv6, the format is a:b:c:d:e:f:g:h where a through h consist of 1 to 4 hexadecimal digits (leading zeros may be omitted). a single series of 0 addresses may be omitted. For example 2001:227:e857:1:0:0:0:0:1 may be written 2001:227:e857:1::1.
A network address refers to 1 or more hosts and consists of a host address followed by a slash ("/") and a Variable Length Subnet Mask (VLSM). This is known as Classless Internet Domain Routing (CIDR) notation.
The VLSM is a decimal number. For IPv4, it is in the range 0 through 32. For IPv6, the range is 0 through 128. The number represents the number of leading bits in the address that represent the network address; the remainder of the bits are a host address and are generally given as zero.
Examples:
IPv4: 192.168.1.0/24
IPv6: 2001:227:e857:1:0:0:0:0:1/64
In the Shorewall documentation and manpages, we have tried to make it clear which type of address is accepted in each specific case.
Because Shorewall uses a colon (":") as a separator in many contexts, IPv6 addresses are best written using the standard convention in which the address itself is enclosed in square brackets:
| [2001:227:e857:1::1] |
| [2001:227:e857:1::]/64 |
Entries in Shorewall configuration files often deal with the source (SOURCE) and destination (DEST) of connections and Shorewall implements a uniform way for specifying them.
A SOURCE or DEST consists of one to three parts separated by colons (":"):
ZONE — The name of a zone declared in
/etc/shorewall/zones or
/etc/shorewall6/zones. This part is only
available in the rules file
(/etc/shorewall/rules,
/etc/shorewall/blrules,
/etc/shorewall6/rules and
/etc/shorewall6/blrules).
INTERFACE — The name of an interface that matches an entry in
/etc/shorewall/interfaces
(/etc/shorewall6/interfaces).
Beginning with Shorweall 5.2.1, the
interface may be preceded with '!' which
matches all interfaces except the one specified.
ADDRESS LIST — A list of one or more addresses (host or network) or address ranges, separated by commas. In an IPv6 configuration, this list must be included in square or angled brackets ("[...]" or "<...>"). The list may have exclusion.
Examples.
All hosts in the net zone — net
Subnet 192.168.1.0/29 in the loc zone — loc:192.168.1.0/29
All hosts in the net zone connecting through ppp0 — net:ppp0
All hosts interfaced by eth3 — eth3
Subnet 10.0.1.0/24 interfacing through eth2
Host 2002:ce7c:92b4:1:a00:27ff:feb1:46a9 in the loc zone — loc:[2002:ce7c:92b4:1:a00:27ff:feb1:46a9]
The primary IP address of eth0 in the $FW zone - $FW:ð0
All hosts in Vatican City - net:^VA (Requires the GeoIP Match capability).