Chapter 2 IP Addressing and Related Topics

IP gateway

(the router or other devicethat will forward traffic to the host ' s physical network)

Physical numeric address

A 6-byte numeric address burned into firmware by network interface manufacturers. The first 3 bytes (known as the organizationally unique identifier , or OUI) identify the manufacturer of whatever interface is in use. The final 3 bytes, are assigned by the manufacturer and give any interface on a network a unique physical numeric address.

The symbolic name

A human-recognizable name that takes a particular form, such as www.support.com. These are called domain names

Domain

Any collection of computing devices connected on a network and administered as a unit.

The physical numeric address

Functions at a sublayer of the Data Link layer called the Media Access Control (MAC) layer In the OSI network reference model, For that reason, it is also known as a Media Access Control (MAC) layer address (or MAC address).

Domain Name

To be valid, must correspond to at least one unique numeric IP address. Domain names only point to numeric addresses; they are not the same as those addresses

Address Resolution Protocol (ARP)

Used to permit computers to translate numeric IP addresses to MAC layer addresses.

Reverse Address Resolution Protocol (RARP)

Used to translate MAC layer addresses into IP addresses

IP renumbering

When this appens, you must switch the addresses on every machine that uses an address from the old ISP to another unique address you obtain from the new ISP.

CIDR

allows IPv4 addresses from Class A, B, or C to be combined and treated as a largeraddress space

subnetting

allows network administrators to match subnetworksto actual routing regions on their networks so that machines on the same physical network can communicate using MAC layer addresses.

For IPv6,

an address consists of 128 bits, and it is expressed as a series of hexadecimal (base-16) values.

constant-length subnet masking (CLSM) ,

in which each subnet includes the same number of stations and representsa simple division of the address space made available by sub netting into multiple equal segments.

Registration

informs the network interface card to pass packets sent to that address to the IPstack so that their contents can be read, and it tells the IP gateway to forward such trafficon to the physical network, where the listening network interface resides.

Intermediate host

is a computer or other networked device that relays network traffic from itsorigin to the destination host

A subnet mask.

is a special bit pattern that " blocks off " the network portion of an IPv4 address with an all-ones pattern

variable-length subnet mask-ing (VLSM)

permits a single address to be subdivided into multiple subnets, in whichsubnets need not all be the same size.

For IPv4,

the logical numeric address consists of a set of four numbers separated by periods