Term | Definition |
ARP | Address Resolution Protocol. An Internet protocol used to map an IP address to a MAC address. Defined in RFC 826. |
default gateway/default router | On an IP host, the IP address of some router to which the host sends packets when the packet’s destination address is on a subnet other than the local subnet |
DHCP | Dynamic Host Configuration Protocol. A protocol used by hosts to dynamically discover and lease an IP address, and learn the correct subnet mask, default gateway, and DNS server IP addresses. |
DNS | Domain Name System. An application layer protocol used throughout the Internet for translating hostnames into their associated IP addresses. |
host part | A term used to describe a part of an IPv4 address that is used to uniquely identify a host inside a subnet. The host part is identified by the bits of value 0 in the subnet mask. |
IP address | A 32-bit address assigned to hosts using TCP/IP. Each address consists of a network number, an optional subnetwork number, and a host number. The network and subnetwork numbers are used for routing; host number is used to address a host within a network. |
logical address | A generic reference to addresses as defined by Layer 3 protocols, which do not have to be concerned with the physical details of the underlying physical media. Used mainly to contrast with data-link (physical) addresses. |
network broadcast address | A special address in each classful network that can be used to broadcast a packet to all hosts in that same classful network. Example: 10.255.255.255 is the network broadcast address for classful network 10.0.0.0. |
network number | A number that uses dotted decimal notation like IP addresses, but the number itself represents all hosts in a single Class A, B, or C IP network. |
network address | See network number. |
network part | The portion of an IPv4 address that is either 1, 2, or 3 octets/bytes long, based on whether the address is in a Class A, B, or C network. |
routing table | A list of routes in a router, with each route listing the destination subnet and mask, the router interface out which to forward packets destined to that subnet, and, as needed, the next-hop router’s IP address. |
subnet broadcast address | A special address in each subnet, specifically the largest numeric address in the subnet, designed so that packets sent to this address should be delivered to all hosts in that subnet. |
subnet number | In IP v4, a dotted decimal number that represents all addresses in a single subnet. Numerically, the smallest value in the range of numbers in a subnet, reserved so that it cannot be used as a unicast IP address by a host. |
subnet address | See subnet number. |
subnet part | In a subnetted IPv4 address, interpreted with classful addressing rules, one of three parts of the structure of an IP address, with the subnet part uniquely identifying different subnets of a classful IP network. |