Can a dynamic IP set itself to an IP someone else once used?

[Lysander]

I have a dynamic IP which changes itself every so often.

I just tried to go to 4chan and I got the message I had been permanently banned for started a 'jailbait thread' on 14th January 2010. Now, I did no such thing because

a] I've never started a thread like that
b] I wasn't even living here in January 2010

The 'appeal' box had the gmail address and appeal plea of the person who had been banned still written in it. Weird.

Anyway, I just reset my router and I can access the site and my IP has changed.

So clearly your IP can set itself to someone else's old IP - and you can get in trouble for anything associated with that IP. That's a bit off, isn't it? Or does the IP cycle with various combinations which are always related to to the same property?

 

[Lysander]

Yes, its a dynamic IP, there is a finite pool of IP's for each ISP and each area, so its entirely possible to get an old IP, in fact I would say every IP has been used before. Probably multiple times. Same as phone numbers.

That explains it, how annoying. So it's not confined just to one property? Anyone could get that IP from that ISP?

OP, why are you involved in distribution of child pornography?

Weird comment.