Classless IP routing replaces a classfull address with:
A.
a generalized “IP prefix”
B.
a generalized “IP suffix”
C.
a specialized “IP prefix”
D.
a specialized “IP suffix”
Explanation:
Basically, CIDR eliminates the concept of class A, B, and C networks and replaces this with a
generalized “IP prefix”. CIDR can be used to perform route aggregation in which a single route can
cover the address space of several “old-style” network numbers and thus replace a lot of old
routes. This lessens the local administrative burden of updating external routing, saves routing
table space in all backbone routers and reduces route flapping (rapid changes in routes), and thus
CPU load, in all backbone routers. CIDR will also allow delegation of pieces of what use d to be
called “network numbers” to customers, and therefore make it possible to utilize the available
address space more efficiently.