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Dig (command)
dig is a network administration command-line tool for querying the Domain Name System (DNS). dig (Domain Information Groper) is useful for network troubleshooting and for educational purposes. It can operate based on command line option and flag arguments, or in batch mode by reading requests from an operating system file. When a specific name server is not specified in the command invocation, it uses the operating system's default resolver, usually configured in the file resolv.conf. Without any arguments it queries the DNS root zone. dig supports Internationalized domain name (IDN) queries. dig is a component of the domain name server software suite BIND. dig supersedes in functionality older tools, such as nslookup and the program host; however, the older tools are still used in complementary fashion. Example usage Basic In this example, dig is used to query for ''any'' type of record information in the domain ''example.com'': $ dig example.com any ; DiG 9.6.1 exa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Host (Unix)
host is a simple utility for performing Domain Name System lookups. Origin It was developed by the Internet Systems Consortium (ISC), and is released under the Mozilla Public License 2.0. Modes When applied to a fully qualified domain name (FQDN) the host command will return information associated with that name such as its IP address and mail handling host. It can also be used to list all members of a domain. The host command is also able to perform reverse IP lookups to find the FQDN associated with an IP address. Example $ host example.com example.com has address 93.184.216.34 example.com has IPv6 address 2606:2800:220:1:248:1893:25c8:1946 example.com mail is handled by 0 . See also * BIND name server * dig, a utility interrogates DNS servers directly for troubleshooting and system administration purposes. * nslookup, another utility that can be used to obtain similar information * Root name server - top-level name servers providing top level domain name resolution * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Host (Unix)
host is a simple utility for performing Domain Name System lookups. Origin It was developed by the Internet Systems Consortium (ISC), and is released under the Mozilla Public License 2.0. Modes When applied to a fully qualified domain name (FQDN) the host command will return information associated with that name such as its IP address and mail handling host. It can also be used to list all members of a domain. The host command is also able to perform reverse IP lookups to find the FQDN associated with an IP address. Example $ host example.com example.com has address 93.184.216.34 example.com has IPv6 address 2606:2800:220:1:248:1893:25c8:1946 example.com mail is handled by 0 . See also * BIND name server * dig, a utility interrogates DNS servers directly for troubleshooting and system administration purposes. * nslookup, another utility that can be used to obtain similar information * Root name server - top-level name servers providing top level domain name resolution * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nslookup
nslookup (from ''name server lookup'') is a network administration command-line tool for querying the Domain Name System (DNS) to obtain the mapping between domain name and IP address, or other DNS records. Overview nslookup was a member of the BIND name server software. Early in the development of BIND 9, the Internet Systems Consortium planned to deprecate nslookup in favor of host and dig. This decision was reversed in 2004 with the release of BIND 9.3 and nslookup has been fully supported since then. Unlike dig, nslookup does not use the operating system's local Domain Name System resolver library to perform its queries, and thus may behave differently. Additionally, vendor-provided versions may include output of other sources of name information, such as host files, and Network Information Service. Some behaviors of nslookup may be modified by the contents of resolv.conf. The Linux version of nslookup was written by Andrew Cherenson. The ReactOS version was developed by L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Systems Consortium
Internet Systems Consortium, Inc., also known as ISC, is a Delaware-registered, 501(c)(3) non-profit corporation that supports the infrastructure of the universal, self-organizing Internet by developing and maintaining core production-quality software, protocols, and operations. ISC has developed several key Internet technologies that enable the global Internet, including: BIND, ISC DHCP and Kea. Other software projects no longer in active development include OpenReg and ISC AFTR (an implementation of an IPv4/IPv6 transition protocol based on Dual-Stack Lite). ISC operates one of the 13 global authoritative DNS root servers, F-Root. Over the years a number of additional software systems were operated under ISC (for example: INN and Lynx) to better support the Internet's infrastructure. ISC also expanded their operational activities to include Internet hosting facilities for other open-source projects such as NetBSD, XFree86, kernel.org, secondary name-service (SNS) for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Domain Name System
The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to each of the associated entities. Most prominently, it translates readily memorized domain names to the numerical IP addresses needed for locating and identifying computer services and devices with the underlying network protocols. The Domain Name System has been an essential component of the functionality of the Internet since 1985. The Domain Name System delegates the responsibility of assigning domain names and mapping those names to Internet resources by designating authoritative name servers for each domain. Network administrators may delegate authority over sub-domains of their allocated name space to other name servers. This mechanism provides distributed and fault tolerance, fault-tolerant service and was designed to avoid a single ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whois
WHOIS (pronounced as the phrase "who is") is a query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block or an autonomous system, but is also used for a wider range of other information. The protocol stores and delivers database content in a human-readable format.RFC 3912, ''WHOIS Protocol Specification'', L. Daigle (September 2004) The current iteration of the WHOIS protocol was drafted by the Internet Society, and is documented in . Whois is also the name of the command-line utility on most UNIX systems used to make WHOIS protocol queries. In addition WHOIS has a sister protocol called ''Referral Whois'' ( RWhois). History Elizabeth Feinler and her team (who had created the Resource Directory for ARPANET) were responsible for creating the first WHOIS directory in the early 1970s. Feinler set up a server in Stanford's Network Information Center (NIC) w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Name Server
A root name server is a name server for the root zone of the Domain Name System (DNS) of the Internet. It directly answers requests for records in the root zone and answers other requests by returning a list of the authoritative name servers for the appropriate top-level domain (TLD). The root name servers are a critical part of the Internet infrastructure because they are the first step in resolving human-readable host names into IP addresses that are used in communication between Internet hosts. A combination of limits in the DNS and certain protocols, namely the practical size of unfragmented User Datagram Protocol (UDP) packets, resulted in a decision to limit the number of root servers to thirteen server addresses. The use of anycast addressing permits the actual number of root server instances to be much larger, and is 1,553 . Root domain The DNS is a hierarchical naming system for computers, services, or any resource participating in the Internet. The top of that hiera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MX Record
A mail exchanger record (MX record) specifies the mail server responsible for accepting email messages on behalf of a domain name. It is a resource record in the Domain Name System (DNS). It is possible to configure several MX records, typically pointing to an array of mail servers for load balancing and redundancy. Overview Resource records are the basic information element of the Domain Name System (DNS). An MX record is one of these, and a domain may have one or more of these set up, as below: Domain TTL Class Type Priority Host example.com. 1936 IN MX 10 onemail.example.com. example.com. 1936 IN MX 10 twomail.example.com. The characteristic payload information of an MX record is a preference value (above labelled "Priority"), and the domain name of a mailserver ("Host" above). The priority field identifies which mailserver should be preferred - in this case the values are both 10, so mail would be expected to flow evenly to both ''onemail.ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of DNS Record Types
This list of DNS record types is an overview of resource records (RRs) permissible in zone files of the Domain Name System The Domain Name System (DNS) is a hierarchical and distributed naming system for computers, services, and other resources in the Internet or other Internet Protocol (IP) networks. It associates various information with domain names assigned to ... (DNS). It also contains pseudo-RRs. Resource records Other types and pseudo-RRs Other types of records simply provide some types of information (for example, an HINFO record gives a description of the type of computer/OS a host uses), or others return data used in experimental features. The "type" field is also used in the protocol for various operations. Obsolete record types Progress has rendered some of the originally defined record-types obsolete. Of the records listed at IANA, some have limited use, for various reasons. Some are marked obsolete in the list, some are for very obscure services, some are ... [...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] |
BIND
BIND () is a suite of software for interacting with the Domain Name System (DNS). Its most prominent component, named (pronounced ''name-dee'': , short for ''name daemon''), performs both of the main DNS server roles, acting as an authoritative name server for DNS zones and as a recursive resolver in the network. As of 2015, it is the most widely used domain name server software, and is the ''de facto'' standard on Unix-like operating systems. Also contained in the suite are various administration tools such as nsupdate and dig, and a DNS resolver interface library. The software was originally designed at the University of California, Berkeley (UCB) in the early 1980s. The name originates as an acronym of ''Berkeley Internet Name Domain'', reflecting the application's use within UCB. The latest version is BIND 9, first released in 2000 and still actively maintained by the Internet Systems Consortium (ISC) with new releases issued several times a year. Key features BIND 9 is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internationalized Domain Name
An internationalized domain name (IDN) is an Internet domain name that contains at least one label displayed in software applications, in whole or in part, in non-latin script or alphabet, such as Arabic, Bengali, Chinese (Mandarin, simplified or traditional), Cyrillic (including Bulgarian, Russian, Serbian and Ukrainian), Devanagari, Greek, Hebrew, Hindi, Tamil or Thai or in the Latin alphabet-based characters with diacritics or ligatures, such as French, German, Italian, Polish, Portuguese or Spanish. These writing systems are encoded by computers in multibyte Unicode. Internationalized domain names are stored in the Domain Name System (DNS) as ASCII strings using Punycode transcription. The DNS, which performs a lookup service to translate mostly user-friendly names into network addresses for locating Internet resources, is restricted in practice to the use of ASCII characters, a practical limitation that initially set the standard for acceptable domain names. The intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
