Subject: Re: Off-topic: Dumb IPNAT question
To: Takahiro Kambe <taca@sky.yamashina.kyoto.jp>
From: Paul Goyette <paul@whooppee.com>
List: current-users
Date: 06/15/1998 19:00:38
On Tue, 16 Jun 1998, Takahiro Kambe wrote:

> Based on /usr/share/examples/ipf/nat.eg as an example,
> ipnat.rules bellow works on FreeBSD with ip-filter (not firewall
> function with FreeBSD).
> 
> map ed1 10.1.0.0/16 -> 240.1.0.1/32 proxy ftp ftp/tcp
> map ed1 10.1.0.0/16 -> 240.1.0.1/32 portmap tcp 10000:20000
> map ed1 10.1.0.0/16 -> 240.1.0.0/24

This could be bad news for some devices, since the 240.x.x.x address
range falls into the "reserved" Class E (E = Experimental) range, and
some devices might well discard them.

You'd be much better off using the address ranges that are officially
reserved for use in private networks (including those behind NATs):

	10.0.0.0/8	(One "Class A" network of 2^^24 hosts)
	172.16.0.0/12	(Four "Class B" networks of 65K hosts each)
	192.168.0.0/16	(255 "Class C" networks of 254 hosts each)


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