can you count the letter d in:
q: is it possible for networks to be assigned the same external ip is it possible for networks to be assigned the same external ip, not necessarily simultaneously, for example being assigned another users old external ip address? i am a programming student but my networking knowledge is not great. i did some research and i found out that modern computers use dhcp to get an external ip address dynamically after a set time period. in this case then it makes logical sense that you can use someone elses old ip address.
however if that is true then how would it be possible to trace online activity back to you? i would appreciate a detailed explanation.
many thanks,
rainy

a: of course. there are only 4 billion ip addresses and if address once used, could not be used again, we would have run out those a long time ago. on some networks, you get new address every time you connect. and you can even get address that was vacated just seconds ago.
isps keep record of who used what address at what time. so when tracing someone back, you have to specify the address and the time. then its as easy as with per-user unique addresses.

user
In the text, there are 50 "d"s.
assistant