Different router different WAN Ips?

[Byte]

I've been playing around with a linksys and a belkin router. When ever i change the router, the WAN external dynamic IP changes too. Why does this happen?

 

[gunrunnerjohn]

Because you're making a new connection, and they obviously always reset the DHCP lease when you disconnect.

 

[ScottMac]

DHCP leases are issued to the MAC address. When you change routers, you're changing the MAC.

If it's an issue, do MAC spoofing on one router to match the other router's MAC.

Good Luck

Scott

 

[skyking]

Exactly as Scott said. I drag the NIC in my router box into any new router box I am testing, so I can keep my IP without doing spoofing in freeBSD.

 

[Byte]

both routers seems to have its own IP that it likes, when i change to the linksys, its always the same, when i switch to teh belkin its always the same on respectively. I've been switching them out, and resetting my modem many times in the past two days, but they always seem to want to keep thier own WAN IPs for some strange reason. I don't even have to reset my cable modem, it just switches to its respective IP when i switch them in and out. I've had my Linksys IP for like 3 years, and would like to keep it.

 

[skyking]

it is tied to the MAC address of the hardware. get the MAC address of the one you have had, and find the place in the router configuration on the other one that is called "MAC Cloning" or spoofing. Enter the MAC address of your old router in there, and you should get the same IP as the old router.

 

[gunrunnerjohn]

Originally posted by: ScottMac
DHCP leases are issued to the MAC address. When you change routers, you're changing the MAC. If it's an issue, do MAC spoofing on one router to match the other router's MAC. Good Luck Scott

Well... that depends. For Comcast in my area, the DHCP lease is tied to the MAC address of my DOCSIS modem, and I can change routers or plug in directly, and when I renew, I still have the same IP address. Every couple of months, I'll notice for some reason the IP address has changed, but it has nothing to do with the MAC address of my connected equipment.

 

[mboy]

Originally posted by: gunrunnerjohn

Originally posted by: ScottMac
DHCP leases are issued to the MAC address. When you change routers, you're changing the MAC. If it's an issue, do MAC spoofing on one router to match the other router's MAC. Good Luck Scott

Well... that depends. For Comcast in my area, the DHCP lease is tied to the MAC address of my DOCSIS modem, and I can change routers or plug in directly, and when I renew, I still have the same IP address. Every couple of months, I'll notice for some reason the IP address has changed, but it has nothing to do with the MAC address of my connected equipment.

Ditto with OOL. changing routers, NIc's etc has absolutely ZERO effect on my WAN IP addy. They sell it as a dynamic IP, but in reality I have only had it change 2 or 3xs over the past 3 years.