Plz answer only if you know for certain.....?

Question

what the numbers in an IP address mean/stand for? Being harassed by someone poating false ads containing my email address, and was given the IP addresses that were used for each post. the numbers are identical, except for the end-- the last few numbers after the last decimal. Is this coincidence? Someone told me the first few numbers represent the service/internet provider used, the next few identify the city, and the last few the actual computer/person. Is this true? Find it hard to believe that the fact that the numbers are almost identical could be just a coincidence, since it is obviously one person repeatedly reposting the harassing/impersonating ad, unless they are using library computers.

Answer 1

The numbers don't exactly stand for anything, but they do identify the ISP who provides the access to the user, and can identify the actual machine the e-mail was sent from.  For example, AT&T owns the entire 12.x.x.x network block, and they distribute those addresses throughout the world.  To narrow down the information, you can go to http://dnsstuff.com and enter the ip address in the IP Information field on the left side of the page, that will tell you who owns the block, and may or may not give an approximate location of the subnet.  However, without evidence of a crime, the ISP will not reveal any information about who used the IP at the time in question.