Provided by: shorewall-common_4.2.10-1_all
nat - Shorewall one-to-one NAT file
This file is used to define one-to-one Network Address Translation
If all you want to do is simple port forwarding, do NOT use this file.
See http://www.shorewall.net/FAQ.htm#faq1. Also, in many cases,
Proxy ARP (shorewall-proxyarp(5)) is a better solution that
The columns in the file are as follows.
EXTERNAL - address
External IP Address - this should NOT be the primary IP address of
the interface named in the next column and must not be a DNS Name.
If you put COMMENT in this column, the rest of the line will be
attached as a comment to the Netfilter rule(s) generated by the
following entries in the file. The comment will appear delimited by
"/* ... */" in the output of "shorewall show nat"
To stop the comment from being attached to further rules, simply
include COMMENT on a line by itself.
INTERFACE - interfacelist[:[digit]]
Interfacees that have the EXTERNAL address. If ADD_IP_ALIASES=Yes
in shorewall.conf(5), Shorewall will automatically add the
EXTERNAL address to this interface. Also if ADD_IP_ALIASES=Yes, you
may follow the interface name with ":" and a digit to indicate that
you want Shorewall to add the alias with this name (e.g.,
"eth0:0"). That allows you to see the alias with ifconfig. That is
the only thing that this name is good for -- you cannot use it
anwhere else in your Shorewall configuration.
Each interface must match an entry in shorewall-interfaces(5).
Prior to Shorewall 4.1.4, this must be an exact match.
Shorewall-perl 4.1.4 and later allow loose matches to wildcard
entries in shorewall-interfaces(5). For example, ppp0 in this
file will match a shorewall-interfaces(5) entry that defines
Prior to Shorewall 4.1.4, interfacelist must be a single interface
name. Beginning with Shorewall-perl 4.1.4, Shorewall-perl users may
specify a comma-separated list of interfaces.
If you want to override ADD_IP_ALIASES=Yes for a particular entry,
follow the interface name with ":" and no digit (e.g., "eth0:").
INTERNAL - address
Internal Address (must not be a DNS Name).
ALL INTERFACES - [Yes|No]
If Yes or yes, NAT will be effective from all hosts. If No or no
(or left empty) then NAT will be effective only through the
interface named in the INTERFACE column.
LOCAL - [Yes|No]
If Yes or yes, NAT will be effective from the firewall system
shorewall(8), shorewall-accounting(5), shorewall-actions(5),
shorewall-blacklist(5), shorewall-hosts(5), shorewall-interfaces(5),
shorewall-maclist(5), shorewall-masq(5), shorewall-netmap(5),
shorewall-params(5), shorewall-policy(5), shorewall-providers(5),
shorewall-routestopped(5), shorewall-rules(5), shorewall.conf(5),
shorewall-tcclasses(5), shorewall-tcdevices(5), shorewall-tcrules(5),
shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)