CIDR
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The term "prefix" as it is used here is equivalent to "CIDR block",
and in simple terms may be thought of as a group of one or more
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... AS, careful thought should be
taken to register appropriately sized CIDR blocks with your
registration authority in order to minimize the number of advertised
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... Fuller, V., T. Li, J. Yu, and K. Varadhan, "Classless Inter-Domain Routing (CIDR): an Address Assignment and Aggregation Strategy", RFC 1519(-> 4632) ...