What are the symptoms of an IP address conflict?

System administrators must take special precautions when setting up two DHCP servers on the same network. The most common problem caused by competing DHCP servers is an IP address conflict.

Windows is able to detect IP address conflicts and will warn users about the problem when it occurs. Linux users can detect these problems using system utilities.

In cases where the client is not using a desktop operating system (for example, constrained embedded systems that have TCP/IP support), what are the symptoms (not the causes) of an IP address conflict? I am specifically asking this question from the perspective of a device that does not perform IP conflict detection. What happens when these dangers are ignored? Many sources talk about the causes and steps for remediation, but few explain the symptoms themselves. What will happen if a network administrator ignores best practices and causes IP conflicts on a LAN?

A lot depends on how the embedded system operates, but basically the devices with the conflict will show intermittent connectivity, or perhaps no connectivity at all. If you were to look at devices on the same vlan they communicate with, like the default gateway, you will see the MAC address flipping between the two devices.