Got DHCP from cable modem once, but not anymore. Works with Router.
 

Hey,
this will get confusing...
I have got an cable-modem and an laptop, which was connected to it, and got it's IP by DHCP. Everything worked well.
Then I tried to set up a wireless lan with my old router, but unfortunately it did not work.

However:
Now, I don't get an internet IP by DHCP anymore. The weird thing is following:
My netbook gets an IP by DHCP from the modem, so the modem's DHCP works.
My laptop gets an IP by DHCP, if I set up a (useless) network with my router. So the DHCP-receiving on my laptop works as well.

So why doesn't the laptop gets an IP by DHCP from the modem?
Does anyone know how to fix it, so can surf with my laptop again?

thank you very much in advance
Max

In a nutshell the typical broadband cable service provider plan only provides one IP address and it is associated to the device's MAC which is stored in your MODEM's non volatile memory. Recycling power to the modem will erase the MAC and allow another device to connect.

that did the job. thank you very much!