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Dynamic IPs... fixed cities?

PostPosted: Sun Nov 20, 2005 3:06 am
by FW4
Hey there

Love the site/API (however still limited for Europe)!

But... what with dynamical IPs?
Are they always in the same city? Or is it possible that today my IP is in "CITY A", and tomorrow that IP is in "CITY B" (at about 10 miles from A) ?

Because that's why I don't understand why people would submit their city, if the next day, it might be somewhere else...

I'm no network connaisseur, but I don't know how those /24 block are assigned :-)

Let me know!!

Re: Dynamic IPs... fixed cities?

PostPosted: Tue Nov 29, 2005 1:34 pm
by bfolkens
FW4 wrote:Hey there

Love the site/API (however still limited for Europe)!

But... what with dynamical IPs?
Are they always in the same city? Or is it possible that today my IP is in "CITY A", and tomorrow that IP is in "CITY B" (at about 10 miles from A) ?

Because that's why I don't understand why people would submit their city, if the next day, it might be somewhere else...

I'm no network connaisseur, but I don't know how those /24 block are assigned :-)

Let me know!!


We currently map to a resolution of a /24 instead of a /32 primarily because the latter changes so frequently compared to a /24. If we mapped every persons' IP address, you can imagine how many changes there would be!

Since most people are using some sort of an ISP (unless you're a Tier 1 provider ;)), your ISP will not be moving around all that much (however, we assume you will - or that they will assign your IP address to another person in the meantime) - so for these reasons it's impractical to record locations of /32's... Who knows, maybe someday we'll come up with a GPS plugin ;)

Re: Dynamic IPs... fixed cities?

PostPosted: Tue Dec 27, 2005 2:48 pm
by roby
bfolkens wrote:
FW4 wrote:Hey there

Love the site/API (however still limited for Europe)!

But... what with dynamical IPs?
Are they always in the same city? Or is it possible that today my IP is in "CITY A", and tomorrow that IP is in "CITY B" (at about 10 miles from A) ?

Because that's why I don't understand why people would submit their city, if the next day, it might be somewhere else...

I'm no network connaisseur, but I don't know how those /24 block are assigned :-)

Let me know!!


We currently map to a resolution of a /24 instead of a /32 primarily because the latter changes so frequently compared to a /24. If we mapped every persons' IP address, you can imagine how many changes there would be!

Since most people are using some sort of an ISP (unless you're a Tier 1 provider ;)), your ISP will not be moving around all that much (however, we assume you will - or that they will assign your IP address to another person in the meantime) - so for these reasons it's impractical to record locations of /32's... Who knows, maybe someday we'll come up with a GPS plugin ;)


In Europe an ISP can cover a whole country so a particular IP can be for example used in the the North of Scotland one day and in southern England the next so a city is pretty meaningless in this context.

Re: Dynamic IPs... fixed cities?

PostPosted: Sat Feb 09, 2008 5:10 pm
by JB
It's like that here too.

The ISP I'm using seems to allocate the same /24 to anywhere in about a 300km radius.
if I hit a website that uses geolocated text in adverts the results can be well off-target.