I really need help. I have a site that uses DHCP for all its wireless and wired devices. The router is a Cisco 2901 and hands out IP's dynamically with no problems until this past week. It appears that whenever a computer is turned off and back on, the IP address is changed to a public IP - 192.168.0.x. After some investigation, I realized that it is a device somewhere, we are unable to locate it, that is handing out public IP's. This is forcing me to put static IP's on our computers. I have the mac address and was able to find the brand name of the device, but unable to find the device itself. I put the public ip gateway in one of the computers and was able to pull up a login page, but all the default username/password combination does not work.
Is there a way
1. to find the location of the device;
2. Block it, so that our network won't pick up the addresses.
Thanks so much