Which IP pool configuration maps internal addresses to a specified range of external addresses?

The choice of Fixed port range is attributed to its functionality in mapping internal addresses to a specified range of external addresses, particularly in network address translation (NAT) scenarios. This method allows for a pool of external IP addresses to be dynamically assigned to internal addresses, ensuring that a specific range of external IPs is utilized based on the configured fixed port allocation.

In a Fixed port range configuration, each internal address is mapped to a specific external address with a range of ports. This ensures that traffic from the same internal host using the same external address is allocated to different ports, allowing for multiple sessions while still maintaining identifiable NAT entries for each internal device.

The other options do not specifically focus on the mapping of internal addresses to a defined range of external addresses. For instance, one-to-one mapping refers to a direct association of each internal address with a unique external address, while port block allocation typically refers to reserving sets of ports for applications rather than mapping entire address ranges. Overload, on the other hand, allows multiple internal hosts to share a single external IP address but does not specifically define a range for external addresses. Thus, Fixed port range is the most accurate configuration for mapping internal addresses to a designated external address range.