Can you get two different IP addresses from the same computer?

Question

I have been receiving email from a friend who says he is at home. However, I get two different IP address's from him quite often and they are always the same ones. He does have a router in his home tho and I wonder if this has any bearing on it. Comments are definatley welcome!!!...thanks!!!

Answer 1

if he is using two different computers it is possible and there are also programs that people use to trick the computer into thinking it has a different ip address.

Answer 2

It would depend. Is he sending e-mail from his personal computer, as in outlook express or eudora or sending from a webmail account?

A webmail account will have the IP address that's assigned by his ISP so it's unlikely to change. It might however be one of the addresses you're getting e-mail from.

If he's using a home router, it's probably configured to give out DHCP addresses to his home network.

So if he sends you a message from his Outlook Express account located on his computer, it'll have the locally distributed address. Something like 192.168.1.1.

Then when he sends from the webmail (like Yahoo), it'll have his ISP address, something like 67.203.145.23.

An alternate answer would be that you're getting different 192.168 addresses. If so, it could be affected by him having another computer on (like a laptop) prior to turning on his machine one time and his being the only machine on other occasions. So his DHCP server in the router would give him 192.168.1.2 the first time he logs in to the network and 192.18.1.1 the second time.

He could, and this is much slimmer, have two network cards both plugged into the router thinking he can get a faster network connection. Since each network device would have its own IP address, you could have e-mails coming from one or the other.

Answer 3

If he has a Router, chances are he has at least 2 computers - so maybe he uses both computers for mail etc.

However most home users have a single 'point of contact' to the web and use NAT to 'share' that connection between multiple PC's.... (why pay for 2 web connections when you can pay for one and share it ?)

So my 'best guess' is that he is using a Wireless connection and his PC is occasionally 'linking' to his neighbors Wireless base station. You are seeing 2 IP addresses because one is his and one is his neighbors.

Answer 4

It is possible to get 2 IPs installed.

~Brendon
Hope I helped!