This is the absolute best router you can buy. I apologize for those claiming you absolutely need a modem. That is very dependent on what your internet access point is. If your internet enters your house on RJ45 you absolutely do not need a stand alone modem. If it enters as a phone line or coax (cable) line, then yes you do. I run this as a modem/router with 1gig fiber from Ziply, previously Frontier that was previously Verizon. The switch is done by the ISP outside my house and delivered into my house on RJ45 ports.