[Shumway]

Hooked up an old compaq and i noticed that my ip adress changed but when i hooked up my old comp my ip address went back to my original one,is this normal? is it do to a different network card or what is it?

[DJ-CHRIS]

What IP adresses were they? Sometimes DCHP can be weird and just assign a higher IP when a lower one is available

[mq]

The DHCP server identifies the NIC you have by the MAC address.
For a period of time (called lease) it will assign the same address to a given MAC.

You plugged in a different computer with a different NIC/MAC, therefore it gave you another address, since the old one was still reserved for the MAC on the other computer.

[geffin]

Lets say it's like a wireless network, if it is secured by automatic encryption, you type in a pass key, and it generates a hex key for the network identification. MAC addresses work just like this, except not security drawn... The dhcp server (in this case i'm guessing a router) will read the MAC and produce an IP address. if you change the MAC address of your network card/computer, your ip will change, it's just how DHCP servers do their thing. If you don't want this, you can just access your router (usually 192.168.1.1), and tell it to turn off dhcp. You will of course have to manually enter the ip data on your comps, but by entering 192 ip addresses, the router will accept clients, and your ip will never change.

[Shumway]

Thank's guy's,I just didn't know anything about this and it kind of made me wonder,I found out the address it changed to was just the default gateway number.