Computer Architecture and Design Question:

Answer #1
DNS cache snooping is not a term the author just made up, it is known and discussed by some notable
DNS implementation developers, and a few interested DNS administrators have probably at least heard of it.

Answer #2
In a multiprocessor system, a cache is said to be snooping, if it snoops (monitors) the address line of it\\'s neighbor processor cache to maintain the data to be consistent (data is one cache should be consistent with the other)

Answer #3
In order to maintain coherent caches, each processor needs to make sure that it has a clean copy of memory... It can do this in multiple ways...
One such way is to "snoop" on a common address bus to keep track of what the other caches are doing (modifying/reading data). Such a cache is called a "snooping" cache.