Asante Technologies 3624/48 Configuring IP, Class, Address or Range, Status, CIDR Prefix

Chapter 6: Configuring IP

The Internet Protocol (IP) is a packet-based protocol used to exchange data over computer networks. All other IP protocols are built on the foundation. IP is a network-layer protocol that contains addressing and control information that allows data packets to be routed.

The table below lists the traditional classes and ranges of IP addresses and their status.

Class	Address or Range	Status
A	0.0.0.0	Reserved
	1.0.0.0 to 126.0.0.0	Available
	127.0.0.0	Reserved
B	128.0.0.0 to 191.0.0.0	Available
	255.255.255.0
C	192.0.0.0 to	Available
	223.255.255.0
D	224.0.0.0 to 239.255.255.255	Multicast group addresses
E	240.0.0.0 to 255.255.255.254	Reserved
	255.255.255.255	Broadcast

With the rapid expansion of networks being connected to the Internet, critical problems were seen with the traditional classified addressing scheme. It was possible that IP addresses would run out, and routing tables would be overwhelmed. Thus, the Classless Inter-Domain Routing (CIDR) addressing scheme was created.

CIDR replaces the older process of assigning IP addresses with general prefixes of 8, 16, or 24 bits. CIDR uses prefixes of 13 to 27 bits. A CIDR address includes the standard 32-bit IP address and adds information on how many bits are used for the network prefix. In the IP address 206.203.1.35/27, the “/27” indicates that the first 27 bits are used to identify the unique network, and the remaining bits are used to identify the specific host. Now, blocks of addresses can be better fitted to even very small or very large networks.

The following table describes the Class C equivalent of CIDR prefixes.

CIDR Prefix	Class C Equivalent		Host Addresses
/27	1/8 Class C		32 Hosts
/26	1/4 Class C		64 Hosts
/25	1/2 Class C		128 Hosts
/24	1 Class C		256 Hosts
/23	2 Class C		512 Hosts
/22	4 Class C		1,024 Hosts
/21	8 Class C		2,048 Hosts
/20	16 Class C		4,096 Hosts
46		Asante IntraCore IC3624/48		User’s Manual