Provided by: shorewall_4.4.21-1_all bug

NAME

       nat - Shorewall one-to-one NAT file

SYNOPSIS

       /etc/shorewall/nat

DESCRIPTION

       This file is used to define one-to-one Network Address Translation
       (NAT).

           Warning
           If all you want to do is simple port forwarding, do NOT use this
           file. See http://www.shorewall.net/FAQ.htm#faq1[1]. Also, in many
           cases, Proxy ARP (shorewall-proxyarp[2](5)) is a better solution
           that one-to-one NAT.

       The columns in the file are as follows.

       EXTERNAL - {address|COMMENT}
           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]]
           Interfaces that have the EXTERNAL address. If ADD_IP_ALIASES=Yes in
           shorewall.conf[3](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[4](5).
           Shorewall allows loose matches to wildcard entries in
           shorewall-interfaces[4](5). For example, ppp0 in this file will
           match a shorewall-interfaces[4](5) entry that defines ppp+.

           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

FILES

       /etc/shorewall/nat

SEE ALSO

       http://shorewall.net/NAT.htm

       shorewall(8), shorewall-accounting(5), shorewall-actions(5),
       shorewall-blacklist(5), shorewall-hosts(5), shorewall_interfaces(5),
       shorewall-ipsets(5), shorewall-maclist(5), shorewall-masq(5),
       shorewall-netmap(5), shorewall-params(5), shorewall-policy(5),
       shorewall-providers(5), shorewall-proxyarp(5),
       shorewall-route_rules(5), shorewall-routestopped(5),
       shorewall-rules(5), shorewall.conf(5), shorewall-secmarks(5),
       shorewall-tcclasses(5), shorewall-tcdevices(5), shorewall-tcrules(5),
       shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)

NOTES

        1. http://www.shorewall.net/FAQ.htm#faq1
           http://www.shorewall.net/manpages/../FAQ.htm#faq1

        2. shorewall-proxyarp
           http://www.shorewall.net/manpages/shorewall-proxyarp.html

        3. shorewall.conf
           http://www.shorewall.net/manpages/shorewall.conf.html

        4. shorewall-interfaces
           http://www.shorewall.net/manpages/shorewall-interfaces.html

[FIXME: source]                   07/10/2011                  SHOREWALL-NAT(5)