IP addresses

[robotics]

Is it possible for two computers located in different parts of the country to have the same IP address,

How and why would two people have the same IP address, is it not unique to one computer.

[Buenchico]

Different PCs shouldn't have the same IP address simultaneously (otherwise the data stream intended for one PC could be received by the other). However, the same IP address can be used by different PCs at different times

Dial-up ISP services normally allocate IP addresses 'dynamically'. The IP address which I am using to post this message is currently unique to my PC but, as soon as I log off, my ISP can allocate it to another user. (i.e. the IP address is 'owned' by the ISP who share it around different users). The next time I log on, my ISP will once again allocate an IP address to my PC. This will almost certainly be different to my current one but will have recently been 'freed up' by someone else logging off.

IP addresses define the country and the ISP of the user but not the specific geographic area. So, when I log off here in East Anglia, the next user of this IP address could be anywhere else in the country.

If two PCs do simultaneously share the same IP address (which, theoretically) should never happen, it can only be because they share the same ISP which is experiencing software problems.

Chris

[Buenchico]

Oops!

A bracket seems to have moved in that last sentence! I think that it probably makes sense though ;-)

Chris

[robotics]

Need to explain further

I have my own forum and four members that have signed up have the same IP address, I have asked them are they all the same person to be told no,

I have done a tracert on the ip address and the router/isp provider is located in ********* which is nowhere where they say there,

I was under the impression that an IP address, is unique to the computer/router used, just like no two BT customers could have the same telephone number.

[kempie]

Are you looking at the public IP addresses of each of the members' machines, or the IP address of one proxy server they are all using to access the web?

[Buenchico]

I think Kempie has solved the mystery. Many people route all their internet traffic through a proxy server. (I've done so myself on some occasions). It's simply a way of preserving anonymity. If the proxy server is a well known free one, a simple Google search on its ISP address should show it appearing on one of the many web pages which list free proxy servers. If these forum members are using a paid service, there probably won't be as many 'hits' on Google but it's still likely that it will be identifiable.

Alternatively, of course, the four users might actually be the same person. There are plenty of people here on AB, for example, who've got multiple user names!

Chris

[robotics]

Could this proxy be something like hidemyass.com

[robotics]

I also think the mystery is solved

[OBonio]

It could be different users at the same company. Their IP address will show as their company's outgoing router's IP whilst they themselves will be using an internal non routable IP address like the 192.168.*.* range.