Sprint Filters - what are they?

Wed Apr 16 03:50:24 UTC 1997

Sprint currently filters announcements from its
non-customers as follows:

        RFC 1597 reserved space: accept nothing                     (**)
        In the classical "A" space: accept nothing longer than /8      
        In the classical "B" space: accept nothing longer than /16
                in 24/8 space: accept nothing longer than /19       (*)
                in 195/8: accept nothing longer than /19
                in 206/8 - 223/8: accept nothing longer than /19
                in 192/8 - 205/8: accept nothing longer than /24    

(*)  in-line with the IP registries allocation
(**) RFC 1597>  Private Address Space

RFC 1597>   The Internet Assigned Numbers Authority (IANA) has reserved
RFC 1597>   the following three blocks of the IP address space for private
RFC 1597>   networks:
RFC 1597>        10.0.0.0        -   10.255.255.255
RFC 1597>        172.16.0.0      -   172.31.255.255
RFC 1597>        192.168.0.0     -   192.168.255.255

Vab..

On Tue, 15 Apr 1997, Gregory Hersh wrote:

> A while ago we had a customer with some routing problems which were caused
> by Sprint filters (127/8 - 191/8, deny anything longer than /16). When
> customer called Sprint, he's been told by someone from tech support that
> 'Sprint doesn't filter anything'. When I called support, I've been told
> that on 127/8 - 191/8 range Sprint denies anything longer than /16. This
> morning the same customer called Sprint again, to confirm this information,
> and been told that for the above range Sprint denies anything longer than /19.
> It seems like each time you call Sprint support, you hear a different story.
> 
> Will someone from Sprint _who knows_ confirm their filtering policy which
> I have as follows:
> 
> 0/8 - 126/8, deny subnets of historical A's
> 127/8 - 191/8, deny anything longer than /16
> 192/8 - 205/8, deny anything longer than /24
> 206/8 - 223/8, dney anything longer than /19
> 192/8 [RIPE], deny anything longer than /19
> 
> 
> It would be really nice to have it posted at NANOG web page as well
> (alas, only AGIS done so).
> 
> Thanks,
> 
> - Greg -
> 