Using RIR info to determine geographic location...
tme at multicasttech.com
Mon Dec 24 13:50:19 UTC 2007
On Dec 24, 2007, at 1:23 AM, James Hess wrote:
> On Dec 20, 2007 8:13 PM, Greg Skinner <gds at best.com> wrote:
>> Personally, I have trouble accepting some of the claims the
>> geotargeting companies have made, such as Quova's 99.9% to the
>> level, and 95% to the US state level. ( More info at
>> http://www.quova.com/page.php?id=132 ) Perhaps I'm just part of the
> The trouble with a claim of "95%" accuracy is the method of
> determining the accuracy
> of the measurement has not been indicated, and there are _many_ IPs
> out there.
> With no method of obtaining the statistic indicated: there is no
> evidence I saw
> that 99%/95%, weren't possibly just made up numbers for the purpose of
> aggressively marketing a product.
Well, I use a geolocation service, and as I travel around to many
fine hotels and meetings,
I try to check frequently to see if it knows where I am, so I have a
few dozen test probes scattered about the globe.
The results are mixed. On US corporate (enterprise) networks, it is
typically unreliable. In-room
hotel networks generally get mapped to the right city. Wireless hot
spots are erratic - sometimes mapped
to better than a km, sometimes wildly off. People's home networks,
generally the right country, frequently the right city.
I would say, overall
- mapping to the right country, probably better than 95% accuracy,
- mapping to the right city, at least 75% of the time, for sure not
99%, even if you discount enterprise networks.
Of course, your probable error may vary...
> I agree it is not very believable that a geolocation service properly
> locates 95%
> of all ip addresses to within a state/city.
> Due to the existence of various types of proxies and anonymizer
> visible IP often does not reveal original requestor details.
> RIR records give contact information for an organization utilizing IP
> space, that's
> not the same as the physical location of nodes -- it makes the RIR
> data an
> unreliable source of information for that usage.
> This information is not necessarily always up to date in the first
> Nodes on the very same RIR allocation may be geographically distant.
> No more reliable than performing traceroutes to the destination IP,
> reverse resolving, and
> using pattern matching to search for possible city, state, country
> names contained in
> the reverse DNS mappings of the hops nearest the target.
> (Since providers sometimes include state and/or city names in
> router rDNS hosts)
> On the other hand, it's perhaps the best geolocators can _try_ to
> Short of geolocation services manually calling ISPs and asking.../
> making deals with major ISPs to procure lists of geographic regions
> assigned IPs in those regions.
> I suppose that in theory proper geolocation close to 95% of IPs for
> page access
> requests would occur then (provided 95% of page access requests
> came from
> providers they had that type of direct information from)
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