Dot-decimal notation
Encyclopedia
Dot-decimal notation is a presentation format for numerical data. It consists of a string of decimal numbers, each pair separated by a full stop
(dot).
A common use of dot-decimal notation is in information technology where it is a method of writing numbers in octet
-grouped base-10 (decimal
) numbers separated by dots (full stop
s). In computer networking, Internet Protocol Version 4 addresses
are commonly written using the quad-dotted notation of four decimal integers, ranging from 0 to 255 each.
For example, the hexadecimal number 0xFF0000 is expressed in dot-decimal notation as 255.0.0.
In computer networking, the term is often used as a synonym of dotted quad notation,
or quad-dotted notation, a specific use to represent Internet Protocol Version 4 addressess
.
Object identifier
s use a style of dot-decimal notation to represent an arbitrarily deep hierarchy of objects identified by arbitrary decimal numbers.
Common decimal fractions are sometimes said to be written in dotted decimal notation. For example the fraction 1/8 is represented as 0.125.
An Internet Protocol Version 4 (IPv4) address consists of 32 bits, which may be divided into four octets. These four octets are written in decimal numbers, ranging from 0 to 255, and are concatenated as a character string with full stop delimiters between each number.
For example, the address of the loopback
interface, usually assigned the host name localhost
, is 127.0.0.1. It consists of the four binary octets 01111111, 00000000, 00000000, and 00000001, forming the full 32-bit address.
representation. Therefore, if an IP address component is written with a leading 0 digit, it may be interpreted incorrectly by some utility programs
. For example, the representation 022.101.031.153 is interpreted as 18.101.25.153 in decimal notation.Similarly, standard IP addresses can be written with a leading 0x to mean a hexadecimal address: pinging 133.45.0xEE.0x10 pings the decimal address 133.45.238.16.
Full stop
A full stop is the punctuation mark commonly placed at the end of sentences. In American English, the term used for this punctuation is period. In the 21st century, it is often also called a dot by young people...
(dot).
A common use of dot-decimal notation is in information technology where it is a method of writing numbers in octet
Octet (computing)
An octet is a unit of digital information in computing and telecommunications that consists of eight bits. The term is often used when the term byte might be ambiguous, as there is no standard for the size of the byte.-Overview:...
-grouped base-10 (decimal
Decimal
The decimal numeral system has ten as its base. It is the numerical base most widely used by modern civilizations....
) numbers separated by dots (full stop
Full stop
A full stop is the punctuation mark commonly placed at the end of sentences. In American English, the term used for this punctuation is period. In the 21st century, it is often also called a dot by young people...
s). In computer networking, Internet Protocol Version 4 addresses
IP address
An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...
are commonly written using the quad-dotted notation of four decimal integers, ranging from 0 to 255 each.
Definition and use
Dot-decimal notation is a presentation format for numerical data expressed as a string of decimal numbers each separated by a full stop.For example, the hexadecimal number 0xFF0000 is expressed in dot-decimal notation as 255.0.0.
In computer networking, the term is often used as a synonym of dotted quad notation,
or quad-dotted notation, a specific use to represent Internet Protocol Version 4 addressess
IP address
An Internet Protocol address is a numerical label assigned to each device participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing...
.
Object identifier
Object identifier
In computing, an object identifier or OID is an identifier used to name an object . Structurally, an OID consists of a node in a hierarchically-assigned namespace, formally defined using the ITU-T's ASN.1 standard. Successive numbers of the nodes, starting at the root of the tree, identify each...
s use a style of dot-decimal notation to represent an arbitrarily deep hierarchy of objects identified by arbitrary decimal numbers.
Common decimal fractions are sometimes said to be written in dotted decimal notation. For example the fraction 1/8 is represented as 0.125.
IPv4 address
For example, the address of the loopback
Loopback
Loopback describes ways of routing electronic signals, digital data streams, or flows of items from their originating facility back to the source without intentional processing or modification...
interface, usually assigned the host name localhost
Localhost
In computer networking, localhost is the standard hostname given to the address of the loopback network interface. The name is also a reserved top-level domain name In computer networking, localhost (meaning this computer) is the standard hostname given to the address of the loopback network...
, is 127.0.0.1. It consists of the four binary octets 01111111, 00000000, 00000000, and 00000001, forming the full 32-bit address.
Caveat
In information technology, an integer number that starts with the digit 0 is often interpreted as a number in octalOctal
The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three...
representation. Therefore, if an IP address component is written with a leading 0 digit, it may be interpreted incorrectly by some utility programs
Utility software
Utility software is system software designed to help analyze, configure, optimize or maintain a computer. A single piece of utility software is usually called a utility or tool....
. For example, the representation 022.101.031.153 is interpreted as 18.101.25.153 in decimal notation.Similarly, standard IP addresses can be written with a leading 0x to mean a hexadecimal address: pinging 133.45.0xEE.0x10 pings the decimal address 133.45.238.16.