Cisco router going into Netgear router. Netgear supplying dhcp to computers and voip phones. Phones plug into wall, computers plug into phones. Computers obtain ip address autonatically, same for dns servers. When computers reboot, in networksettings, the dns server says use the following address, it is the same ip address as the computer. Users have to go in and check the radio button to obtain address automatically. Any idea what could be causing this?

Faulty router? Cisco voip router causing the issue?