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IP address to location resolution


Can anyone explain the technology behind IP address to geograhic location resolution?

There are companies like GeoBytes and Quova that sells this service.


Alex Choo
Wednesday, February 5, 2003

They work using various of ways. But starting at the very top (think thousands of acres).. basically top level network providers assign regions of ip addresses to geographical location. They had to take away ip addresses a while back to do this, but it was relatively painless because of DNS (you just assign a different ip to the same domain).. But there are times when that just won't work, because the organization using can't give it up--for security reasons for example--that's why those RSA guys are making so much money, because IP and DNS both can be spoofed--and we need client and server authentication using cryptography to ensure you really are downloading service packs from Microsoft, your CIBC account number isn't going to the bahamas, and your Flash upgrade hasn't been hacked...

At lower levels, network providers that are small are shrinking.. or they buy their services (and ip pools) from the big guys. Again, the big guys knows the addresses of the region the little guys are covering. Say any random contiguous zipcode ranges--and you just associate that with the ip number.

Roaming using mobile ip is no problem. Because once the packets exits the laptop over the VPN out of the company firewall it's really home. So if you are in Germany but your company FedEx is in Atlanta, your packets are coming from there. This all helps mapping make sense in the end.

But this is all coming out of my rear end. Check with the experts :D

-- David

Li-fan Chen
Thursday, February 6, 2003

IP addresses (or the block that they are in) can be queried with the address space registrars.  This information can often be grepped for the address of the registrant.

This is possibly why when Joel talked recently about Peer1 s/he said that google assumed s/he was in Canada and redirected him/her to

Also for fun look at:

Thursday, February 6, 2003

You can use ARIN.NET to take an IP and find the company that is assigned the block containing that value.  For example " is  Using whois on ARIN.NET that maps to:

Peer 1 Network Inc. PEER1-BLK-03 (NET-66-199-128-0-1)
Peer1 Internet Bandwidth PEER1-NYCAT1AVLAN1-04 (NET-66-199-177-112-1)

That does not aways give you a percise location, but it's a start.

Thursday, February 6, 2003

should be: 
That does not always give you a precise location, but it's a start.

...and I can't always spell this early...

Thursday, February 6, 2003

Part of the reason IP pools were assigned with geography and regions in mind is to reduce the load on most routing tables. It's the table used to look up where to send the packet request from your computer to the destination server. Having pools and regions physically mapped helps reduce the processing power and memory requirements of routers a lot.

Li-fan Chen
Thursday, February 6, 2003

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