IP address question

I was messing around online today and found a site that told you what your IP address was. It had a detailed summary of the company and the location.

It said I was located in some town in Missouri, and listed a company I had never heard of. I live in Kansas, and this got me kind of curious so I checked it with another site. It gave me the same information.

Maybe I don’t know how IP addresses work, but I thought they had something to do with where your internet connection was located. What was going on with these sites? Are IP addresses part of a larger network and that’s what it was telling me?

Nothing too important, I was just curious. Thanks!

IP addresses indicate a network and a specific node on that network. That’s all. They don’t have anything to do with physical location, though we can make certain guesses depending on how much information we have.

If we know to what company a specific IP address belongs (this is easy to look up in publically available databases) then we can then look up where that company is located. But there’s no telling what’s behind that IP address – it may be a private dedicated line connected to some network 500 miles away, a dialup connection used by someone halfway around the world, or a NAT gateway for a large corporate intranet that spans the globe.

So your ISP, or its upstream provider, probably has a physical presence somewhere in Missouri. Not surprising, since Kansas is nearby.

Thanks! That cleared it up for me.

One more question: Then what’s the big deal about not giving out your IP address?

I always assumed that you weren’t supposed to give it out because people could track where you lived or something, but I guess not.

Publishing your IP isn’t going to make your life collapse around you, but keeping it concealed is a reasonable way to err on the side of caution.

It’s kind of like your street address… while it’s public knowledge, and easily known to anyone who visits your house or sends you mail correspondence, you don’t want to give it out indiscriminately because hooligans might just decide to come toilet-paper your house. Likewise giving out your IP address on, say, a message board would make it easier for tech-savvy adversaries to harass you. For people who haven’t taken steps to conceal their location, the IP address usually does reveal something about the general location of your internet provider. So if you’re particularly paranoid about not letting anyone know anything whatsoever about your location… let’s say you’re claiming to be reporting from the mideast when you’re really in Amsterdam… well, obviously it makes it difficult to play games like that.

You “give out” your IP address every time you connect to another computer on the Internet. For example, every time you read a page on the SDMB.

But you’re only giving it to the target computer. When I post to SDMB, that server must see and does see my IP address. Nobody else sees it, or needs to see it (intermediates like DNS and routers excluded).

You have no idea what those intermediaries are. They can change completely at random and no indiciation whatsoever is visible to you. That’s an important part of how the Internet was designed; it’s called ‘fault-tolerance’. Point being, there’s absolutely no way to control which machines see your IP address.

On the plus side, it’s nowhere near as personal as a street address. Which this thread has already ably demonstrated. The people who can harm you just by knowing an IP address are the people who can harm you without needing to know an IP address. (Governments, in other words. Your government, in plain words.)

Word of warning though, for many people your IP address will pinpoint you to a town accurately. If you live in a relatively nonpopulous area, then you may be easier to identify you than you think. If you’re using a company connection your IP address will often identify the company you work for. Or the school you go to.