Re: ip prefix-list rfc1918-dsua - "Documenting Special Use

Hi Brian,

Thanks for the comment.

I guess I am still trying to compile my study notes and to determine
what I should memorize along under this topic.

I plan on leaving out RFC3330 and Bogon (knowing about but not to memorize).

So far I have RFC 1918 and I thought this so called rfc1918-dsua. A
big problem seems to be matching terminology definitively to a
specific prefix list.

Rgds,
Rich

On Thu, May 21, 2009 at 4:03 PM, Brian McGahan
<bmcgahan_at_internetworkexpert.com> wrote:
> This could be considered "good" practice, but not "best" practice. The
> actual list that should be used for non-valid routes on the Internet is
> known as the Bogon list, which can be found here:
> http://www.cymru.com/Documents/bogon-bn.html. The problem with using RFC
> 3330 is that it is no longer accurate. For example, 24.0.0.0/8 is listed in
> 3330 as special use, but now it is available for normal allocation.
>
> Brian McGahan, CCIE #8593 (R&S/SP/Security)
> bmcgahan_at_INE.com
>
> Internetwork Expert, Inc.
> http://www.INE.com
> Toll Free: 877-224-8987 x 705
> Outside US: 775-826-4344 x 705
>
>
> Rich Collins wrote:
>
> Hello,
>
> I've been revisiting this topic which has been brought up many times
> in one form or another on this list. Today I stumbled upon a
> reference to a Cisco document with this prefix list.
>
> It is a general purpose prefix list meant for external BGP peerings.
> I understand that this prefix lists includes the RFC1918 range and
> other special purpose address ranges but not full RFC 3330. I take it
> to mean that this list is "good practice".
>
>
> ip prefix-list rfc1918-dsua deny 0.0.0.0/8 le 32
> ip prefix-list rfc1918-dsua deny 10.0.0.0/8 le 32
> ip prefix-list rfc1918-dsua deny 127.0.0.0/8 le 32
> ip prefix-list rfc1918-dsua deny 169.254.0.0/16 le 32
> ip prefix-list rfc1918-dsua deny 172.16.0.0/12 le 32
> ip prefix-list rfc1918-dsua deny 192.0.2.0/24 le 32
> ip prefix-list rfc1918-dsua deny 192.168.0.0/16 le 32
> ip prefix-list rfc1918-dsua deny 224.0.0.0/4 le 32
> ip prefix-list rfc1918-dsua permit 0.0.0.0/0 le 32
>
> Should it include the Class E deny 240.0.0.0/4
> possibly? Otherwise
> does it look accurate and make sense to memorize (versus a longer list
> such as RFC3330)?
>
> -Rich
>
>
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Received on Thu May 21 2009 - 18:12:34 ART