Of course the "GeoIP people" are going to vet the submissions, but if
existing entry is Spain or Germany and the traceroute shows that the
previous hop was somewhere in the US midwest, I think they can
figure it
out. =)
The "hop before it" is not necessarily a good indication these days
with MPLS tunnels. There is this thing called the Speed Of Light.
It's very annoying most of the time, but it can be useful for geo
location if you have multiple vantage points to ping / trace to a
destination.
The return packet can be delayed infinitely, but it cannot be sped up
past c. Really about 0.666c if you believe the path is in fiber,
which I personally believe is a useful assumption for every path on
the 'Net to several decimal places (since things like satellite hops,
while not in fiber, will give your far higher latency, and microwave
just is not used enough to matter). If you ping something from San
Jose and get a response in under 50 ms, the machine which sent the
reply packet _cannot_ be in Germany or China. Those pesky Laws of
Physics get in the way.[*]
What's more, if you ping the same destination from, say, Los Angeles
and Boston, and each test returns in 40 ms, you now have narrowed the
possible locations down quite a bit.
There are always exceptions, but sometimes they are obvious. Pinging
the same destination from LAX & BOS and getting 5 ms each... well,
that's obviously anycast (or a broken test). Fortunately, most
destinations are unicast and stationary, so there are ways to narrow
down the location using tools like this.
--
TTFN,
patrick
[*] Technically it's the Theory of Relativity which gets in the way.
This means some people will argue I am wrong because it is "only a
theory" and not proven fact. Hopefully no NANOG reader has ever used
lines like "it is only a theory" against "theories" which are better
proven than some "laws" (e.g. the Law of Gravity, which, as it turns
out, is wrong).
On May 1, 2009, at 5:39 PM, Frank Bulk wrote:
I wouldn't mind create LOC records for our IP address ranges, but
doesn't
make much sense if the "GeoIP people" don't look at it or care.
Hence the
need for someone who is relevant to them to open the dialog.
I've never received a negative comment when submitting a correction
request
to "GeoIP people". Of course, they don't make it really easy to do
so and
it seems that half the time it needs to be done via back-channels.
Of course the "GeoIP people" are going to vet the submissions, but if
existing entry is Spain or Germany and the traceroute shows that the
previous hop was somewhere in the US midwest, I think they can
figure it
out. =) I'm sure they have mechanisms to track changes and new
allocations,
but some things will slip through the cracks or in the case of use
sales
data, be delayed.
The process that I'm suggesting is for corrective action, not to be
the
basis for the "GeoIP people" to build their database. That's why I'm
suggesting a comprehensive form that gets sent to all the "GeoIP
people".
It's a way they can receive requests in a systematic way that can
help them
improve the accuracy of their database.
Frank
-----Original Message-----
From: Peter Beckman [mailto:beck...@angryox.com]
Sent: Friday, May 01, 2009 4:23 PM
To: Mikael Abrahamsson
Cc: nanog@nanog.org
Subject: Re: how to fix incorrect GeoIP data?
On Fri, 1 May 2009, Mikael Abrahamsson wrote:
On Fri, 1 May 2009, William F. Maton Sotomayor wrote:
LOC records too. :-)
dig @prisoner.iana.org hostname.as112.net any
Have this seen any widespread use? I mean, there needs to be tens of
percent
of users having these before they'll get used by the GeoIP people.
People who are evil (or people seeking privacy) will intentionally
put bad
data, thus ruining the whole thing.
I don't think self-reporting is the answer.
You MIGHT be able to determine location based on a traceroute, though
anycast would surely derail such attempts. I suspect most people
rely on
3rd party GeoIP databases, and that those companies aren't
interested in
hearing from you about your location change, mostly because they are
worried that if they do, the evildoers will overrun them with bad
requests, or bait and switch, making their data less accurate than
it is
now without your block being correct.
Which I can understand.
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Peter Beckman
Internet Guy
beck...@angryox.com http://www.angryox.com/
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