Final answer:
The DNS security feature in Windows Server 2012 that allows for source port randomization is the 'Socket pool'. It increases security by making it harder for attackers to predict query source ports, mitigating risks such as cache poisoning.
Step-by-step explanation:
The DNS security feature in Windows Server 2012 that can be configured to allow source port randomization for DNS queries is known as Socket pool. This feature is crucial as it enhances the security of DNS transactions by making it more difficult for attackers to predict the source port used for DNS queries, thereby reducing the risk of cache poisoning and other DNS-related attacks.
To configure the Socket pool, you will need to adjust the settings in the DNS server properties within Windows Server 2012. This is typically accessed through the DNS Manager console where the settings for the socket pool can be defined, including the size of the pool that determines the range of ports used for DNS queries.