Ubuntu Manpage: exclusion - Exclude a set of hosts from a definition in a shorewall configuration file.

NAME

       exclusion - Exclude a set of hosts from a definition in a shorewall configuration file.

SYNOPSIS

       !address-or-range[,address-or-range]...

       !zone-name[,zone-name]...

DESCRIPTION

The first form of exclusion is used when you wish to exclude one or more addresses from a
definition. An exclamation point is followed by a comma-separated list of addresses. The
addresses may be single host addresses (e.g., 192.168.1.4) or they may be network
addresses in CIDR format (e.g., 192.168.1.0/24). If your kernel and iptables include
iprange support, you may also specify ranges of ip addresses of the form
lowaddress-highaddress

No embedded white-space is allowed.

Exclusion can appear after a list of addresses and/or address ranges. In that case, the
final list of address is formed by taking the first list and then removing the addresses
defined in the exclusion.

Beginning in Shorewall 4.4.13, the second form of exclusion is allowed after all and any
in the SOURCE and DEST columns of shorewall-rules[1](5). It allows you to omit arbitrary
zones from the list generated by those key words.

Warning
If you omit a sub-zone and there is an explicit or explicit CONTINUE policy, a
connection to/from that zone can still be matched by the rule generated for a parent
zone.

For example:

/etc/shorewall/zones:

#ZONE TYPE
z1 ip
z2:z1 ip
...

/etc/shorewall/policy:

#SOURCE DEST POLICY
z1 net CONTINUE
z2 net REJECT

/etc/shorewall/rules:

#ACTION SOURCE DEST PROTO DPORT
ACCEPT all!z2 net tcp 22

In this case, SSH connections from z2 to net will be accepted by the generated z1 to
net ACCEPT rule.

In most contexts, ipset names can be used as an address-or-range. Beginning with Shorewall
4.4.14, ipset lists enclosed in +[...] may also be included (see shorewall-ipsets[2] (5)).
The semantics of these lists when used in an exclusion are as follows:

• !+[set1,set2,...setN] produces a packet match if the packet does not match at least
one of the sets. In other words, it is like NOT match set1 OR NOT match set2 ... OR
NOT match setN.

• +[!set1,!set2,...!setN] produces a packet match if the packet does not match any of
the sets. In other words, it is like NOT match set1 AND NOT match set2 ... AND NOT
match setN.

EXAMPLES

       IPv4 Example 1 - All IPv4 addresses except 192.168.3.4
           !192.168.3.4

       IPv4 Example 2 - All IPv4 addresses except the network 192.168.1.0/24 and the host
       10.2.3.4
           !192.168.1.0/24,10.1.3.4

       IPv4 Example 3 - All IPv4 addresses except the range 192.168.1.3-192.168.1.12 and the
       network 10.0.0.0/8
           !192.168.1.3-192.168.1.12,10.0.0.0/8

       IPv4 Example 4 - The network 192.168.1.0/24 except hosts 192.168.1.3 and 192.168.1.9
           192.168.1.0/24!192.168.1.3,192.168.1.9

       Example 5 - All parent zones except loc
           any!loc

FILES

       /etc/shorewall/hosts

       /etc/shorewall/masq

       /etc/shorewall/rules

       /etc/shorewall/tcrules

NOTES