renew ip?

[Twofish]

Im trying to renew the external ip adress of my router, but everytime i release/renew it gets the same ip.
If i connect the adsl modem to my pc i get a completely new ipadress and when i connect the router it gets the old ipadress ive always had when using my router.

[Ark+]

when i connect the router it gets the old ipadress ive always had when using my router.

It just mean that your ISP has a good DHCP allocation. The DHCP server resend the same IP address for a given MAC adress (of course if address is still available).
You may try to change the ASUS Mac address by changing the nvram variable in order to get a new address...