A DBA is an acronym for "doing business as". It's a fictitious name statement, usually filed with the county clerk of the county where you do business. When a sole proprietor wishes to do business under a different name, he files a DBA (aka fictitious name statement). So if I wanted to start a business under the name "Dan's Plumbing", I could file a DBA under "Dan's Plumbing".
I presume the IP address of your ISP doesn't even come into it because a Google spider has no connection with that? Just so fearful that they might trace all my sites by my ISP IP address. I know it doesn't sound logical but I wonder if my lack of knowledge in the area means I am missing something.