Lucent Technologies Release 8.2 manual IP Addressing, Physical Addressing, Logical Addressing

IP Addressing 1 Networking Overview

IP Addressing

This section describes IP addressing, subnetting, and routing.

Physical Addressing

The Address Resolution Protocol (ARP) software on the C-LAN circuit pack relates the 32-bit logical IP address, which is configured in software, with the 48-bit physical address of the C-LAN circuit pack, which is burned into the board at the factory. The C-LAN board has an ARP table that associates the IP addresses with the hardware addresses, which are used to route messages across the network. Each C-LAN board has one physical address and up to 17 assigned IP addresses (one for each port).

Logical Addressing

Format

Dotted Decimal notation

An IP address is a software-defined 32-bit binary number that identifies a network node. The IP address has two main parts -- the first n bits specify a “network ID” and the remaining 32 – n bits specify a “host ID.”

	n	32 – n
Class	Network ID	Host ID
Type

The 32-bit binary IP address is what the computer understands. For human use, the address is typically expressed in dotted decimal notation — the 32 bits are grouped into four 8-bit octets (bytes) and converted to decimal numbers separated by decimal points, as in the example below.

Octet 1	Octet 2	Octet 3	Octet 4
11000010	00001101	11011011	00000111

194 . 13 . 219 . 7

The eight binary bits in each octet can be combined to represent decimal numbers ranging from 0 to 255.

Administration for Network Connectivity
555-233-504 — Issue 1 — April 2000	CID: 77730	13