nanog mailing list archives

Re: UUNet Routing SNAFU


From: "Alec H. Peterson" <ahp () hilander com>
Date: Wed, 8 Oct 1997 23:17:09 -0400

On Wed, Oct 08, 1997 at 07:39:52PM -0700, David Carmean wrote:

I installed the ACL Sean posted back in December of '95, updated by 
changes he posted in June of '96.  Is that list still reasonable?

I'm pretty sure that is the version that filters >=207 at /19 (instead
of /18 which is where he initially put the filter).  However, keep in
mind that the registries have been allocating space out of old class A
space, which all versions of his filter I've seen _will_ block.  So,
depending on your policy you would want to add:

access-list xxx permit ip 62.0.0.0 0.255.255.255 0.0.0.0 255.255.255.0

Do that for 24/8, 62/8 and any other blocks that the IANA has released
to a registry (I think Dorian mentioned 63/8 and 64/8 as well).  Of
course, if you want to filter on /19 then your mask will be a little
different.

Of course, one can just do what Randy suggested and filter all class A
space at /19 and be done with it.

Alec

-- 
+------------------------------------+--------------------------------------+
|Alec Peterson - ahp () hilander com    | Erols Internet Services, INC.        |
|Network Engineer                    | Springfield, VA.                     |
+------------------------------------+--------------------------------------+


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