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Zone File
A Domain Name System (DNS) zone file is a text file that describes a DNS zone. A DNS zone is a subset, often a single domain, of the hierarchical domain name structure of the DNS. The zone file contains mappings between domain names and IP addresses and other resources, organized in the form of text representations of resource records (RR). A zone file may be either a DNS master file, authoritatively describing a zone, or it may be used to list the contents of a DNS cache., ''Domain Names - Implementation and Specification'', P. Mockapetris, (November 1987) File format The format of a zone file is defined in (section 5) and (section 3.6.1). This format was originally used by the Berkeley Internet Name Domain (BIND) software package, but has been widely adopted by other DNS server software – though some of them (e.g. NSD, PowerDNS) are using the zone files only as a starting point to compile them into database format, see also Microsoft DNS with Active Directory-database int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Information Sciences Institute
The USC Information Sciences Institute (ISI) is a component of the University of Southern California (USC) Viterbi School of Engineering, and specializes in research and development in information processing, computing, and communications technologies. It is located in Marina del Rey, California. ISI actively participated in the information revolution, and it played a leading role in developing and managing the early Internet and its predecessor ARPAnet.Bekey, George A. ''"A Remarkable Trajectory: From Humble Beginnings to Global Prominence'', The history of the USC Viterbi School of Engineering." Charleston: CreateSpace, 2015. Print. The Institute conducts basic and applied research supported by more than 20 U.S. government agencies involved in defense, science, health, homeland security, energy and other areas. Annual funding is about $100 million. ISI employs about 400 research scientists, research programmers, graduate students and administrative staff at its Marina del ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time To Live
Time to live (TTL) or hop limit is a mechanism which limits the lifespan or lifetime of data in a computer or network. TTL may be implemented as a counter or timestamp attached to or embedded in the data. Once the prescribed event count or timespan has elapsed, data is discarded or revalidated. In computer networking, TTL prevents a data packet from circulating indefinitely. In computing applications, TTL is commonly used to improve the performance and manage the caching of data. Description The original DARPA Internet Protocol's RFC document describes TTL as: IP packets Under the Internet Protocol, TTL is an 8-bit field. In the IPv4 header, TTL is the 9th octet of 20. In the IPv6 header, it is the 8th octet of 40. The maximum TTL value is 255, the maximum value of a single octet. A recommended initial value is 64. The time-to-live value can be thought of as an upper bound on the time that an IP datagram can exist in an Internet system. The TTL field is set by the sender ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Localhost
In computer networking, localhost is a hostname that refers to the current device used to access it. It is used to access the network services that are running on the host via the loopback network interface. Using the loopback interface bypasses any local network interface hardware. Loopback The local loopback mechanism may be used to run a network service on a host without requiring a physical network interface, or without making the service accessible from the networks the computer may be connected to. For example, a locally installed website may be accessed from a Web browser by the URL it is mainly used for web development purposes ''http://localhost'' to display its home page. The name ''localhost'' normally resolves to the IPv4 loopback address , and to the IPv6 loopback address . Name resolution IPv4 network standards reserve the entire address block 127.0.0.0/8 (more than 16 million addresses) for loopback purposes. Updated by RFC 8190. That means any packet sent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Localhost
In computer networking, localhost is a hostname that refers to the current device used to access it. It is used to access the network services that are running on the host via the loopback network interface. Using the loopback interface bypasses any local network interface hardware. Loopback The local loopback mechanism may be used to run a network service on a host without requiring a physical network interface, or without making the service accessible from the networks the computer may be connected to. For example, a locally installed website may be accessed from a Web browser by the URL it is mainly used for web development purposes ''http://localhost'' to display its home page. The name ''localhost'' normally resolves to the IPv4 loopback address , and to the IPv6 loopback address . Name resolution IPv4 network standards reserve the entire address block 127.0.0.0/8 (more than 16 million addresses) for loopback purposes. Updated by RFC 8190. That means any packet sent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Top-level Domain
A top-level domain (TLD) is one of the domains at the highest level in the hierarchical Domain Name System of the Internet after the root domain. The top-level domain names are installed in the root zone of the name space. For all domains in lower levels, it is the last part of the domain name, that is, the last non empty label of a fully qualified domain name. For example, in the domain name www.example.com, the top-level domain is .com. Responsibility for management of most top-level domains is delegated to specific organizations by the ICANN, an Internet multi-stakeholder community, which operates the Internet Assigned Numbers Authority (IANA), and is in charge of maintaining the DNS root zone. History Originally, the top-level domain space was organized into three main groups: ''Countries'', ''Categories'', and ''Multiorganizations''. An additional ''temporary'' group consisted of only the initial DNS domain, arpa, and was intended for transitional purposes toward the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNS Root Zone
The DNS root zone is the top-level DNS zone in the hierarchical namespace of the Domain Name System (DNS) of the Internet. Before October 1, 2016, the root zone had been overseen by the Internet Corporation for Assigned Names and Numbers (ICANN) which delegates the management to a subsidiary acting as the Internet Assigned Numbers Authority (IANA). Distribution services are provided by Verisign. Prior to this, ICANN performed management responsibility under oversight of the National Telecommunications and Information Administration (NTIA), an agency of the United States Department of Commerce. Oversight responsibility transitioned to the global stakeholder community represented within ICANN's governance structures. A combination of limits in the DNS definition and in certain protocols, namely the practical size of unfragmented User Datagram Protocol (UDP) packets, resulted in a practical maximum of 13 root name server addresses that can be accommodated in DNS name query response ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fully Qualified Domain Name
A fully qualified domain name (FQDN), sometimes also referred to as an ''absolute domain name'', is a domain name that specifies its exact location in the tree hierarchy of the Domain Name System (DNS). It specifies all domain levels, including the top-level domain and the root zone. A fully qualified domain name is distinguished by its lack of ambiguity in terms of DNS zone location in the hierarchy of DNS labels: it can be interpreted only in one way. Definition A fully qualified domain name is conventionally written as a list of domain labels separated using the full stop “” character (''dot'' or ''period''). The top of the hierarchy in an FQDN begins with the rightmost label. For instance, in the FQDN , is a label directly under the root zone, is nested under , and finally is nested under . The topmost layer of every domain name is the DNS root zone, which is expressed as an empty label and can be represented in an FQDN with a trailing dot, such as . A trailing dot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Mail Transfer Protocol
The Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients typically use SMTP only for sending messages to a mail server for relaying, and typically submit outgoing email to the mail server on port 587 or 465 per . For retrieving messages, IMAP (which replaced the older POP3) is standard, but proprietary servers also often implement proprietary protocols, e.g., Exchange ActiveSync. SMTP's origins began in 1980, building on concepts implemented on the ARPANET since 1971. It has been updated, modified and extended multiple times. The protocol version in common use today has extensible structure with various extensions for authentication, encryption, binary data transfer, and internationalized email addresses. SMTP servers commonly use the Transmission Control Protocol on port number 25 (for plaintext) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chaosnet
Chaosnet is a local area network technology. It was first developed by Thomas Knight and Jack Holloway at MIT's AI Lab in 1975 and thereafter. It refers to two separate, but closely related, technologies. The more widespread was a set of computer communication packet-based protocols intended to connect the then-recently developed and very popular (within MIT) Lisp machines; the second was one of the earliest local area network (LAN) hardware implementations. Origin The Chaosnet protocol originally used an implementation over CATV coaxial cable modeled on the early Xerox PARC Ethernet, the early ARPANET, and Transmission Control Protocol (TCP). It was a contention-based system intended to work over a range, that included a pseudo-slotted feature intended to reduce collisions, which worked by passing a virtual token of permission from host to host; successful packet transmissions updated each host's knowledge of which host had the token at that time. Collisions caused a host to f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Name Server
A name server refers to the server component of the Domain Name System (DNS), one of the two principal namespaces of the Internet. The most important function of DNS servers is the translation (resolution) of human-memorable domain names (example.com) and hostnames into the corresponding numeric Internet Protocol (IP) addresses (192.0.2.1), the second principal name space of the Internet, which is used to identify and locate computer systems and resources on the Internet. Although it is typically used in reference to DNS (Domain Name System), the term name server may also be used for any computer application that implements a network service for providing responses to queries against a directory service which translates an often humanly meaningful, text-based identifier to a system-internal, often numeric identification or addressing component. This service is performed by the server in response to a service protocol request. Domain Name Server The Internet maintains two princi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Directory
Active Directory (AD) is a directory service developed by Microsoft for Windows domain networks. It is included in most Windows Server operating systems as a set of processes and services. Initially, Active Directory was used only for centralized domain management. However, Active Directory eventually became an umbrella title for a broad range of directory-based identity-related services. A server running the Active Directory Domain Service (AD DS) role is called a domain controller. It authenticates and authorizes all users and computers in a Windows domain type network, assigning and enforcing security policies for all computers, and installing or updating software. For example, when a user logs into a computer that is part of a Windows domain, Active Directory checks the submitted username and password and determines whether the user is a system administrator or normal user. Also, it allows management and storage of information, provides authentication and authorization mec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Format
A file format is a standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary or free. Some file formats are designed for very particular types of data: PNG files, for example, store bitmapped images using lossless data compression. Other file formats, however, are designed for storage of several different types of data: the Ogg format can act as a container for different types of multimedia including any combination of audio and video, with or without text (such as subtitles), and metadata. A text file can contain any stream of characters, including possible control characters, and is encoded in one of various character encoding schemes. Some file formats, such as HTML, scalable vector graphics, and the source code of computer software are text files with defined syntaxes that allow them to be used for specific purposes. Specifications ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
