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AXFR
DNS zone transfer, also sometimes known by the inducing DNS query type AXFR, is a type of DNS transaction. It is one of the many mechanisms available for administrators to replicate DNS databases across a set of DNS servers. A zone transfer uses the Transmission Control Protocol (TCP) for transport, and takes the form of a client–server transaction. The client requesting a zone transfer may be a secondary server requesting data from a primary server. The portion of the database that is replicated is a zone. Operation Zone transfer consists of a preamble, followed by the actual data transfer. The preamble comprises a lookup of the Start of Authority (SOA) resource record for the "zone apex", the node of the DNS namespace that is at the top of the "zone". The fields of this SOA resource record, in particular the "serial number", determine whether the actual data transfer need to occur at all. The client compares the serial number of the SOA resource record with the serial ... [...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-tolerant service and was designed to avoid a single large central ... [...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 t ... (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 ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Back-end Database
{{No footnotes, date=December 2021 A back-end database is a database that is accessed by users indirectly through an external application rather than by application programming stored within the database itself or by low level manipulation of the data (e.g. through SQL commands). A back-end database stores data but does not include end-user application elements such as stored queries, forms, macros or reports. The back-end database concept was invented by Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washi ... in 1989. Enterprise database systems The term back-end database is not widely used among developers using larger or enterprise database systems. This is because enterprise database systems enforce the use of the client–server model and do not have the option to inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attack Surface
The attack surface of a software environment is the sum of the different points (for " attack vectors") where an unauthorized user (the "attacker") can try to enter data to or extract data from an environment. Keeping the attack surface as small as possible is a basic security measure. Elements of an attack surface Worldwide digital change has accelerated the size, scope, and composition of an organization’s attack surface. The size of an attack surface may fluctuate over time, adding and subtracting assets and digital systems (e.g. websites, hosts, cloud and mobile apps, etc). Attack surface sizes can change rapidly as well. Digital assets eschew the physical requirements of traditional network devices, servers, data centers, and on-premise networks. This leads to attack surfaces changing rapidly, based on the organization’s needs and the availability of digital services to accomplish it. Attack surface scope also varies from organization to organization. With the rise of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-master Replication
Multi-master replication is a method of database replication which allows data to be stored by a group of computers, and updated by any member of the group. All members are responsive to client data queries. The multi-master replication system is responsible for propagating the data modifications made by each member to the rest of the group and resolving any conflicts that might arise between concurrent changes made by different members. Multi-master replication can be contrasted with primary-replica replication, in which a single member of the group is designated as the "master" for a given piece of data and is the only node allowed to modify that data item. Other members wishing to modify the data item must first contact the master node. Allowing only a single master makes it easier to achieve consistency among the members of the group, but is less flexible than multi-master replication. Multi-master replication can also be contrasted with failover clustering where passive r ... [...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 Process (computing), processes and Windows service, 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 authentication, authenticates and authorization, authorizes all users and computers in a Microsoft Windows, Windows domain type network, assigning and enforcing security policies for all computers, and installing or updating software. For example, when a user login, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Djbdns
The djbdns software package is a DNS implementation. It was created by Daniel J. Bernstein in response to his frustrations with repeated security holes in the widely used BIND DNS software. As a challenge, Bernstein offered a $1000 prize for the first person to find a security hole in djbdns, which was awarded in March 2009 to Matthew Dempsky. , djbdns's tinydns component was the second most popular DNS server in terms of the number of domains for which it was the authoritative server, and third most popular in terms of the number of DNS hosts running it. djbdns has never been vulnerable to the widespread cache poisoning vulnerability reported in July 2008, but it has been discovered that it is vulnerable to a related attack. The source code has not been centrally managed since its release in 2001, and was released into the public domain in 2007. As of March 2009, there are a number of forks, one of which is dbndns (part of the Debian Project), and more than a dozen patch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire Protocol
In computer networking, a wire protocol refers to a way of getting data from point to point: A wire protocol is needed if more than one application has to interoperate. It generally refers to communication protocols higher than the physical layer. In contrast to transport protocols at the transport level (like TCP or UDP), the term ''wire protocol'' is used to describe a common way to exchange information at the application level. It refers to an application layer protocol and defines all the required attributes for the data exchange, like data types (units of data, message formats, etc.), communication endpoints and capabilities (such as delivery guarantees, direction of communication, etc.). Usually, the data is represented at the application level as a common infoset (e.g. XML, JSON, YAML) and requires a mechanism of data binding (using e.g. a common encoding scheme like XSD). The wire protocol may be either text-based or a binary protocol. Although an important architectural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Transaction
A database transaction symbolizes a unit of work, performed within a database management system (or similar system) against a database, that is treated in a coherent and reliable way independent of other transactions. A transaction generally represents any change in a database. Transactions in a database environment have two main purposes: # To provide reliable units of work that allow correct recovery from failures and keep a database consistent even in cases of system failure. For example: when execution prematurely and unexpectedly stops (completely or partially) in which case many operations upon a database remain uncompleted, with unclear status. # To provide isolation between programs accessing a database concurrently. If this isolation is not provided, the programs' outcomes are possibly erroneous. In a database management system, a transaction is a single unit of logic or work, sometimes made up of multiple operations. Any logical calculation done in a consistent mode in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User Datagram Protocol
In computer networking, the User Datagram Protocol (UDP) is one of the core communication protocols of the Internet protocol suite used to send messages (transported as datagrams in packets) to other hosts on an Internet Protocol (IP) network. Within an IP network, UDP does not require prior communication to set up communication channels or data paths. UDP uses a simple connectionless communication model with a minimum of protocol mechanisms. UDP provides checksums for data integrity, and port numbers for addressing different functions at the source and destination of the datagram. It has no handshaking dialogues, and thus exposes the user's program to any unreliability of the underlying network; there is no guarantee of delivery, ordering, or duplicate protection. If error-correction facilities are needed at the network interface level, an application may instead use Transmission Control Protocol (TCP) or Stream Control Transmission Protocol (SCTP) which are designed for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Start Of Authority
A start of authority record (abbreviated as SOA record) is a type of resource record in the Domain Name System (DNS) containing administrative information about the zone, especially regarding zone transfers. The SOA record format is specified in RFC 1035. Background Normally DNS name servers are set up in clusters. The database within each cluster is synchronized through zone transfers. The SOA record for a zone contains data to control the zone transfer. This is the serial number and different timespans. It also contains the email address of the responsible person for this zone, as well as the name of the primary master name server. Usually the SOA record is located at the top of the zone. A zone without a SOA record does not conform to the standard required by RFC1035. Structure ; NAME: Name of the zone ; TYPE: SOA, abbreviation for ''start of authority'' ; CLASS: Zone class (all but universally IN for internet) ; TTL: Time-to-live ; MNAME: Primary master name server for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
