How polluted is 1/8?

Joel Jaeggli joelja at
Fri Feb 5 05:52:02 UTC 2010

Schiller, Heather A (HeatherSkanks) wrote:
> 14/8 isn't all they are using internally.. 1,4,5,42 and that's just the
> stuff that hasn't been delegated out by IANA yet.  
> I am sure this practice is pervasive.. and it's an issue that doesn't
> typically come up in talks about prepping for IPv4 depletion.  Maybe it
> will now.. 
> FWIW, I don't believe these netblocks are completely unusable.

Nor do I, people will receive assignments out of them, and route them
and cope with the occasional blackhole. Those whose applications or
internal numbering schemes use them will bear a not insignificant cost
associated with mitigation.

> If RIR
> policies permit you to get address space for private networks, it could
> be allocated to an organization that understands and accepts the
> pollution issue because they will never intend to route the space
> publicly.  (Such a thing does exist..)
> +1 volunteering to sink traffic for
>  --heather
> -----Original Message-----
> From: Joel Jaeggli [mailto:joelja at] 
> Sent: Wednesday, February 03, 2010 11:09 AM
> To: Mirjam Kuehne
> Cc: nanog at
> Subject: Re: How polluted is 1/8?
> It should be of no surprise to anyone that a number of the remaining
> prefixes are something of a mess(somebody ask t-mobile how they're using
> 14/8 internally for example). One's new ipv4 assignments are  going to
> be of significantly lower quality than the one received a decade ago,
> The property is probably transitive in that the overall quality of the
> ipv4 unicast space is declining...
> The way to reduce the entropy in a system is to pump more energy in,
> there's always the question however of whether that's even worth it or
> not.
> joel
> Mirjam Kuehne wrote:
>> Hello,
>> After 1/8 was allocated to APNIC last week, the RIPE NCC did some
>> measurements to find out how "polluted" this block really is.
>> See some surprising results on RIPE Labs:
>> Please also note the call for feedback at the bottom of the article.
>> Kind Regards,
>> Mirjam Kuehne

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