IP question

justsomeguy · Post by **justsomeguy** » Sun Aug 15, 2004 3:48 am

ok i got this counter for my site and it has the option of blocking your ip address from going onto the hits, but would other people out there possibly have the same ip number?

Epsilon · Post by **Epsilon** » Sun Aug 15, 2004 4:14 am

No, everybody's IP is unique, however, some internet providers (ie. AOL) changes your IP every time you sign on.

Truggy · Post by **Truggy** » Sun Aug 15, 2004 4:41 pm

Epsilon wrote:No, everybody's IP is unique, however, some internet providers (ie. AOL) changes your IP every time you sign on.

But, it is possible...That 2 people, have the same IP address. It is, rare, but possible.

Raptor · Post by **Raptor** » Sun Aug 15, 2004 5:02 pm

For practical purposes, no, it's not possible. In some instances it may appear that they do. When using a proxy server multiple users can present the same IP to target machines, however, ech client has a private IP and the Proxy handles routing of its reply. Your IP address is like your street address, it must be completely unique to identify the location of the destination of the data. Routing tables only know the next step to reach a specific address block, and that is where the packet goes. At the machine level it is is impossible to have the same IP address on two machines, and have data move at all. In fact, if a windows machine detects a dupe ID address on it's segment, it will throw a warning and disable network communications until the problem is resolved. If they are on different segments of a network, the error may not be recognized, but one of the machines woul dhave to be misconfigured, and totally unable to communicate with other machines, either on their own segment or on other segments through the router. Without getting into router and IP theory too deep, it is impossible for two machines to have the same IP address..

justsomeguy · Post by **justsomeguy** » Sun Aug 15, 2004 5:40 pm

yeah i figured that they couldnt be the same, but i was fixing this one network and it said another machine had the same ip address, so i entered it manually. was that only the ip for the network? cause if you could change it to anything, you could put in someone elses, right?

Raptor · Post by **Raptor** » Mon Aug 16, 2004 12:08 am

Yeah, you can misconfigure the IP, the message you saw was the error mesage that says windows is shutting down communications. If you use DHCP to assign IPs then the chances are almost nill that there will be dupes, unless someone does manuallly enter the IP values...