Re: Sprint filters

["Alec H. Peterson" <ahp () hilander com>]

On Feb 19, 1997, Hank Nussbacher wrote:
> I have an organization which I allocated 147.237.0.0/16 from my country
> block.  They then wanted to subnet and hand out /24s and /23s to the
> dozens of offices they have scattered thru the country and to allow each
> office to connect to whatever ISP they wish.  I told them that Sprint
> would block the announcements of /24s and the like when coming from
> 147.237.0.0.  
>
> They said, then why does Sprint allow its customers to announce /24s from
> their nets?  They gave me as examples: 148.212.0.0 and 145.248.0.0.
> I checked and sure enough here is what I found:

Sprint only applies the prefix length filters to external peers.  All
of Sprint's external peers (as far as I know) peer with AS1239, and
the customers peer with other ASes (such as 1791).  My best guess is
that AS1292 has transit from Sprint, which means they can announce
whatever they want into them.

Alec

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