Can I subnet my network like this ?

[Steve Ames]

On Wed, Jul 30, 2003 at 01:46:09PM +0100, Supote Leelasupphakorn wrote:
>    I heard that it isn't recommend or
> impossible (not sure again) to use FIRST or
> LAST subnet in the allocated IP address pool,
> is it?

That was true at one time. These days it is acceptable to use
all definable subnets (including first and last). If you have
some really old (pre 1995) equipment or software it may be a
bit iffy. See RFC1878: ftp://ftp.rfc-editor.org/in-notes/rfc1878.txt
 
>   Section no.1 is existed and I own the Gateway no.2.
> My plan is enable NAT on it by following the
> instruction in FreeBSD handbook. Any comments are
> welcome.

If your NATting on gateway#2 I don't think the info about gateway
#1 is really relevent...

>        |                                   |
>        | if_1 = 10.0.0.254                 |
>   |---------------| if_2 = 172.16.0.1/16   | section 2
>   | Gateway no.2  |----------------        |
>   |---------------|                        |
>        | if_3 = 172.17.0.1/16              |
>        |                                   |

Lets go on the assumption that if_1 is your external interface
and the one you'll be running natd on?

I'm afraid I don't understand your question then. The subnetting
is fine. You have a full /16 on interface 2 and 3 (way overkill
for most applications but hey :). All of your interfaces are
utilizing valid RFC1918 private IP space.

It should all just work. *shrug*

-Steve