Ch. 4 IP Addressing

Reasons for Subnetting

1. To match the physical layout of the organization 2. To match the administrative structure of the organization 3. To plan for future growth 4. To reduce network traffic

Loopback

127 is reserved as the loopback address. You can use the loopback address range for diagnostics, such as ping. Will show your internal IP configuration.

Subnet

A portion of a network that has been separated from the main network by using a different subnet mask.

Class A

ARIN reserves class A IP addresses for governments and large corporations. Decimal notation will have 1 - 126 in first octet.

Class D

Also known as multicast addresses, are reserved for multicasting; which is the sending of a stream of data (usually audio and video) to multiple computers simultaneously.

ARIN

American Registry of Internet Numbers - manages IP addresses in the United States. Assign Class A, B, and C addresses.

Class C

Assigned to groups that do not meet the qualifications to obtain Class A or B addresses. 192 - 223

Classless Inter-Domain Routing (CIDR)

Developed to slow the exhaustion of IP addresses. Uses a prefix to indicate that the first ___ number of bits in the mask are network bits (1's)

Class B

IP addresses assinged to large and medium sized companies. 128 - 191

Class E

IP addresses reserved for research, testing, and experimentation. 240 - 255

Subnet Mask

Indicates how much of the IP address represents the network or subnet (short for sub-network) A required component for all IP hosts used in combination with an IP address to determine to which subnet the local host belongs. The local host uses this information to determine if the destination is local or remote to the source. Based on this information, the source will either broadcast information on the local network or send its packet to the default gateway for delivery to a remote network.

IANA

Internet Assigned Numbers Authority - devised the hierarchical IP addressing structure.

ICANN

Internet Corporation for Assigned Names and Numbers - A global, government-independent entity with overall responsibility for the Internet. ICANN has effectively replaced IANA.

IP Addressing

The act of assigning unique IP addresses to devices on the network.

VLSM

Variable Length Subnet Masks -