Prefix hijacking, how to prevent and fix currently

Job Snijders job at
Tue Sep 2 16:08:35 UTC 2014

On Tue, Sep 02, 2014 at 11:53:15AM -0400, Christopher Morrow wrote:
> On Tue, Sep 2, 2014 at 11:25 AM, Job Snijders <job at> wrote:
> > What is the real damage of hijacking a prefix which is not in use?
> 'not in use' ... where?
> What if the 'owner' of the block has the block only routed
> 'internally' (either behind gateways/firewalls/airgaps or just inside
> their ASN) The expectation of the 'owner' is that they are using the
> space and it's not routed 'somewhere else', right?

Interesting point. A commmon approach is to announce such internal
prefixes and blackhole packets to and from at a border.

Alternatively they could set "AS 0" in the ROA of such 'not globally
used' prefixes.  I don't think loose mode should apply to 'AS 0' ROAs.

Kind regards,


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