Final answer:
The system undergoing APIPA (Automatic Private IP Addressing) assigns itself an IP address when it cannot contact a DHCP server. APIPA uses a reserved IP range and enables only local network communication.
Step-by-step explanation:
When a system fails to get a DHCP address and assigns itself an IP address, it is undergoing a process known as APIPA (Automatic Private IP Addressing). This situation occurs when the DHCP server is not reachable or unable to service the request. The system then self-assigns an IP address from the reserved range (169.254.0.1 to 169.254.255.254), allowing limited network communication on the local network segment.
APIPA does not require manual configuration and is used as a fallback when a DHCP server is not available to allocate an IP address. However, it's important to note that addresses assigned by APIPA are not routable, restricting communication to the local network only, hence not suitable for accessing the internet or resources outside the local subnet.