I haven't seen a suitable answer so here's my take on it.
If you're looking to obtain a new IP address, I'm going to need a little bit more information about your home network.
If you're behind a router:
You'll need to login to the router (if you'd open a terminal in mac - ps: I don't own a mac nor ever used one but from what I've seen it's similar to linux; then type in ifconfig you'll get the default IP address needed to access your router). Once that's done, you'll need to look for your MAC Address (could be named differently, MAC Clone, etc) settings and you'll need to change the number; example: 00:0d:56:66:b3:ad
Example ifconfig from my home firewall running linux (it's going to differ)Code
[root@firewall.system]/root(1): ifconfig
rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=8<VLAN_MTU>
ether 00:08:54:4a:24:a2
inet 10.0.5.1 netmask 0xffffff00 broadcast 10.0.5.255
inet6 fe80::208:54ff:fe4a:24a2%rl0 prefixlen 64 scopeid 0x1
nd6 options=3<PERFORMNUD,ACCEPT_RTADV>
media: Ethernet autoselect (100baseTX <full-duplex>)
status: active
As you'll see, 10.0.5.1 is the IP I'd use to login to my firewall - with my home network setup it's far different then yours I'm sure since I'm using a firewall router and modem. It's Modem -> Firewall -> Router (router is used for the dhcp releases/wireless connections-ap connections, firewall is used for handling packets/network side of things/etc).Once that's done, you'll then accept the changes/apply them - once your router accepts the changes it might automatically reboot the routers dhcp server, just wait. You'll then need to proceed to your modem and reset it and wait until it's fully turned back on - you should 9 times out of 10 have a new IP unless your ISP has blocked dhcp releases and they've set you up with a static IP.
If you're behind a modem, in Windows *sometimes* it works doing the ipconfig /release and /renew - but your current PC's mac address stays the same usually and it won't be of any use. I'm not entirely sure what it is for MAC since I don't use one - For linux it's : service networking restart or /etc/init.d/network (or networking) restart for most distro's - this doesn't have use to you on a MAC in regards to changing a IP address, you'll need to change the "hwaddr" such as doing a quick: ifconfig -a | grep HWaddr will obtain your current MAC, then you'll do a: ifconfig eth0 down / ifconfig eth0 hw ether 00:0d:56:66:b3:ad (or whatever your current mac is, change 1 number/letter at the end of the mac will work fine) - you'll then just do a quick ifconfig eth0 up - this isn't a guaranteed solution, especially for MAC since I'm not familiar with its command line.
Those are some steps to do and the proper ones for being behind a router. I certainly understand all ISP's are different and some of them issue router+modems bundled and sometimes it'll just require a quick restart of the router and you won't need to change the ghost mac address, but majority of routers do require it.
Try those steps and see what your outcome is or let me know some more information and I'll be able to help you out a bit better.
This post was edited by ius on Jun 18 2011 03:30am