IP address

[poltergeist]

if you hook up to a wireless network you have an ip address. if you change the hard drive and reconnect will you have the same ip address? also what if you have 2 computers connected to the same wireless router will they have the same ip?

[ll_billym]

There are a lot of factors that influence the answer to this but I will assume that you, and the wireless router, have a standard configuration and give you an answer based on this assumption.

Your computer's wireless chip has a unique address embedded in it (MAC address), this is independant of your hard disk or any software. Every time a computer connects to the wireless router it will automatically issue an IP address to it, in most cases the router remembers a MAC address it has seen before and will issue the same IP address to that particular wireless card (and thus particular computer) every time it connects.

On the same local network, IP addresses must be unique as this is the method that is used to identify an individual computer and send traffic to it.

[ll_billym]

Maybe some confusion in my answer, the wireless routers issue IP addresses to computers that connect to them, not the other way round.

[poltergeist]

ok but on my macbook pro I can change my ip address to suit by going into network settings. this whole ip address thing I really dont understand

[rojash]

You can manually configure your IP address or you can (as most do) have the router assign it automatically when you connect.

A typical reason for manually assigning an address is that you want to contact your machine remotely, so need to know its specific address on your own network.

If it's manually assigned then it will always remain the same; if its auto-assigned it may or may not be the same the next time you connect. Neither of these conditions is affected by changing your hard drive (or any other bit of kit - except the network card - and only then if you configure the new card differently from the old one).

And, no, if you have two computers connected to the same router they CANNOT have the same IP, else the router can't tell them apart!

When you go to a site such as http://www.whatsmyip.org/
the IP it tells you is not that of your computer, but that of your router, which is how the rest of the Internet sees you.