Working with IP Addresses Ch. 5

default gateway

A default gateway is the node on the computer network that the network software uses when an IP address does not match any other routes in the routing table.

subnet mask

A dividing line separating an IP address' 32 bits into a group of network bit (on the left) and a group of host bits (on the right)

broadcast address

A logical address at which all devices connected to a multiple-access communications network are enabled to receive datagrams. A message sent to a broadcast address is typically received by all network-attached hosts, rather than by a specific host.

multicast address

A logical identifier for a group of hosts in a computer network, that are available to process datagrams or frames intended to be multicast for a designated network service. Multicast addressing can be used in the Link Layer (Layer 2 in the OSI model), such as Ethernet multicast, and at the Internet Layer (Layer 3 for OSI) for Internet Protocol Version 4 (IPv4) or Version 6 (IPv6) multicast.

Zero configuration networking (Zeroconf)

A set of techniques that automatically creates a usable Internet Protocol (IP) network without manual operator intervention or special configuration servers. Zero configuration networking allows devices such as computers and printers to connect to a network automatically. Without zeroconf, a network administrator must set up services, such as Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS), or configure each computer's network settings manually, which may be difficult and time-consuming. Zeroconf is built on three core technologies: -Assignment of numeric network addresses for networked devices -Automatic resolution and distribution of computer hostnames -Automatic location of network services, such as printing devices

IPv4 subnetting

An IP address has two parts: network number portion and host number portion. The highest order octet (most significant eight bits) in an address was designated as the network number and the remaining bits were called the rest field or host identifier and were used for host numbering within a network.

private IP addressing

ISPs do not route private networks over the public Internet

IPv4 address

In IPv4 an address consists of 32 bits which limits the address space to 4,294,967,296 (2 to a power of 32) possible unique addresses. They are represented in dot-decimal notation, which consists of four decimal numbers, each ranging from 0 to 255, separated by dots, e.g., 172.16.254.1. Each part represents a group of 8 bits (octet) of the address.

classful masks

The default subnet masks associated with address classes A, B, and C

unicast address

Unicast transmission is the sending of messages to a single network destination identified by a unique address.