Change IP address and reset dns to change advertisements

I'm not at all sure that changing your IP and DNS servers will result in "different advertisements", but:

If you're using your own modem and router, the router probably has a "clone MAC address" function that will cause your public IP address to change. You can also set the DNS server addresses of your choice in the router.

 

If you're using a rental Comcast gateway, to change your public IP you'd have to:

• place the device in bridge mode, or
• swap out the device for another, or
• replace your rental gateway with customer-owned equipment

You won't be able to change the DNS server addresses unless you put the gateway in bridge mode and add your own router.