This document doesn't replace documentation relevant to the database software you are
using, ie. README.mysql, README.pgsql or README.sqlite3.

The 'post_nat_ip_src', 'post_nat_ip_dst', 'post_nat_port_src', 'post_nat_port_dst'and
'nat_event' fields.
Such fields are being introduced to support NAT primitives as implemented, for example,
by Cisco NEL implementation. The guidelines below (typically in MySQL format) are to
add such primitives to the SQL schema:

* post_nat_ip_src field:
  - "post_nat_ip_src CHAR(15) NOT NULL," to declare the field itself (*)
  - "PRIMARY KEY (..., post_nat_ip_src, ...)" to put it in the primary key 

* post_nat_ip_dst field:
  - "post_nat_ip_dst CHAR(15) NOT NULL," to declare the field itself (*)
  - "PRIMARY KEY (..., post_nat_ip_dst, ...)" to put it in the primary key

* post_nat_port_src field:
  - "post_nat_port_src INT(2) UNSIGNED NOT NULL," to declare the field itself
  - "PRIMARY KEY (..., post_nat_port_src, ...)" to put it in the primary key 

* post_nat_port_dst field:
  - "post_nat_port_dst INT(2) UNSIGNED NOT NULL," to declare the field itself
  - "PRIMARY KEY (..., post_nat_port_dst, ...)" to put it in the primary key

* nat_event field:
  - "nat_event INT(1) UNSIGNED NOT NULL," to declare the field itself
  - "PRIMARY KEY (..., nat_event, ...)" to put it in the primary key

* fwd_status field:
  - "fwd_status INT(1) UNSIGNED NOT NULL," to declare the field itself
  - "PRIMARY KEY (..., fwd_status, ...)" to put it in the primary key

The primitive is not declared as part of any default table version; yet will not fail
version checks which are enabled when 'sql_optimize_clauses' feature is disabled.

(*) Field must be longer for IPv6 addresses. See README.IPv6 
