Advertising rented IPv4 prefix from a different ASN.

William Herrin bill at
Fri Aug 5 15:47:49 UTC 2016

On Fri, Aug 5, 2016 at 10:01 AM, Blake Hudson <blake at> wrote:
> Andrew wrote on 8/4/2016 2:39 PM:
>>  This space is rented long term but they are not interested in reassigning
>> the space to us.
> Isn't this a violation of their agreement with ARIN
> (

If the space in question is post-1997 then yes, either renting space
as an "end user" or failing to swip reassigned space as an ISP
violates their agreement with ARIN. It could be reported as fraud
making everybody unhappy.

If the edu's space is a legacy assignment then they have no agreement
with ARIN to violate.

On a more practical level, you'll encounter three kinds of trouble:

1. Despite your best efforts, the school will receive some packets
intended for you. Make sure you have a tunnel in place to catch them.

2. Reverse path filtering may trip you up if the school hasn't already
addressed that with their ISPs.

3. Their own internal firewalls and access control mechanisms which
have, over the years, been programmed to act on their entire address

Bill Herrin

William Herrin ................ herrin at  bill at
Owner, Dirtside Systems ......... Web: <>

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