Non-categorical Addressing (CIDR) constitutes an over-grid

CIDR(non-categorical inter-domain route selection)

The main features of CIDR are two:

1. Eliminate the traditional a,b,c address and the concept of sub-network, more efficient allocation of IPv4 address space, CIDR IP address back to the non-classified level two encoding. notation: IP address::={<< network prefix >,<< host number;}. CIDR also uses the "slash notation", which adds "/" after the IP address and then writes the number of bits that the network prefix occupies.
2. CIDR makes up a "CIDR address block" of successive IP addresses that have the same network prefix, that is, enhanced routing aggregation (which constitutes an ultra-network).

Address Mask: is a series of 1 and 0 components, while the number of 1 redemption network prefix length. In the slash notation. The number following the slash is the number of 1 in the address mask.

Make up the net: Shorten the network prefix, the shorter the network prefix, the more the address block contains the number of addresses.

The benefits of CIDR:

• Routing aggregation facilitates the exchange of routing information between routes, thereby improving the overall performance of the Internet.
• Another benefit of using CIDR is the ability to allocate IPV4 address space more efficiently.

In CIDR, you might get more than one match when looking for a routing table, and you should select the route with the longest network prefix from the matching structure, because the longer the network prefix, the smaller the address block, and the more specific the route.

Using CIDR to find the longest prefix match, you should use a two-fork clue, the routing table without classification address in a hierarchical data structure, top-down search by hierarchy. The operation should first find a unique prefix for each IP address, the only prefix is the table in all the IP address, the prefix is unique

CIDR supports routing induction, which aggregates multiple address blocks together, merging many of the routing entries in the routing table into smaller numbers, reducing the size of the router's routing table and reducing the time to route advertisements.

Non-categorical Addressing (CIDR) constitutes an over-grid