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TFTP
Trivial File Transfer Protocol (TFTP) is a simple lockstep File Transfer Protocol which allows a client to get a file from or put a file onto a remote host. One of its primary uses is in the early stages of nodes booting from a local area network. TFTP has been used for this application because it is very simple to implement. TFTP was first standardized in 1981 and the current specification for the protocol can be found in . Overview Due to its simple design, TFTP can be easily implemented by code with a small memory footprint. It is therefore the protocol of choice for the initial stages of any network booting strategy like BOOTP, PXE, BSDP, etc., when targeting from highly resourced computers to very low resourced Single-board computers (SBC) and System on a Chip (SoC). It is also used to transfer firmware images and configuration files to network appliances like routers, firewalls, IP phones, etc. Today, TFTP is virtually unused for Internet transfers. TFTP's design was i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preboot Execution Environment
In computing, the Preboot eXecution Environment, PXE (most often pronounced as ''pixie'', often called PXE Boot/''pixie boot''.) specification describes a standardized client–server environment that boots a software assembly, retrieved from a network, on PXE-enabled clients. On the client side it requires only a PXE-capable network interface controller (NIC), and uses a small set of industry-standard network protocols such as DHCP and TFTP. The concept behind the PXE originated in the early days of protocols like BOOTP/DHCP/TFTP, and it forms part of the Unified Extensible Firmware Interface (UEFI) standard. In modern data centers, PXE is the most frequent choice for operating system booting, installation and deployment. Overview Since the beginning of computer networks, there has been a persistent need for client systems which can boot appropriate software images, with appropriate configuration parameters, both retrieved at boot time from one or more network servers. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sorcerer's Apprentice Syndrome
Sorcerer's Apprentice Syndrome (SAS) is a network protocol flaw in the original versions of TFTP. It was named after Goethe's 1797 poem " Der Zauberlehrling" (popularized by the " Sorcerer's Apprentice" segment of the 1940 animated film ''Fantasia''), because the details of its operation closely resemble the disaster that befalls the sorcerer's apprentice: the problem resulted in an ever-growing replication of every packet in the transfer. The problem occurred because of a known failure mode of the internetwork which, through a mistake on the part of the TFTP protocol designers, was not taken into account when the protocol was designed; the failure mode interacted with several details of the mechanisms of TFTP to produce SAS. Technical background TFTP operates in simple lock-step: there is only ever one packet outstanding at any time, and every packet received by either party caused one packet to be sent in reply (until the termination of the transfer). The TFTP specification sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EFTP
EFTP was a very simple file transfer protocol developed as part of the PARC Universal Packet protocol suite at Xerox PARC in the late 1970s. It was the inspiration for the Trivial File Transfer Protocol (TFTP) in the TCP/IP suite. As with its descendant, TFTP, it did not use the reliable byte stream protocol of the suite ( Byte Stream Protocol in the case of PUP); rather, it ran directly on top of the basic internetwork layer. (An early version of EFTP ran on top of bare Ethernet packets.) Also, like TFTP, it was a simple lock-step protocol; there was only ever one packet outstanding at any time, and every packet received by either party caused one packet to be sent in reply (until the termination of the transfer). Unlike TFTP, it made no provisions for sending the file-name as part of transfers, so it could only be used either in places that didn't need a file name (as with spooling), or in conjunction with another protocol that provided the file-name (as in booting). Since ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File Transfer Protocol
The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data connections between the client and the server. FTP users may authenticate themselves with a clear-text sign-in protocol, normally in the form of a username and password, but can connect anonymously if the server is configured to allow it. For secure transmission that protects the username and password, and encrypts the content, FTP is often secured with SSL/TLS (FTPS) or replaced with SSH File Transfer Protocol (SFTP). The first FTP client applications were command-line programs developed before operating systems had graphical user interfaces, and are still shipped with most Windows, Unix, and Linux operating systems. Many dedicated FTP clients and automation utilities have since been developed for desktops, servers, mobile devices, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Well-known Port
This is a list of TCP and UDP port numbers used by protocols for operation of network applications. The Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) only need one port for duplex, bidirectional traffic. They usually use port numbers that match the services of the corresponding TCP or UDP implementation, if they exist. The Internet Assigned Numbers Authority (IANA) is responsible for maintaining the official assignments of port numbers for specific uses. However, many unofficial uses of both well-known and registered port numbers occur in practice. Similarly, many of the official assignments refer to protocols that were never or are no longer in common use. This article lists port numbers and their associated protocols that have experienced significant uptake. Table legend Well-known ports The port numbers in the range from 0 to 1023 (0 to 210 − 1) are the ''well-known ports'' or ''system ports''. They are used by system processes that provide w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Booting
Network booting, shortened netboot, is the process of booting a computer from a network rather than a local drive. This method of booting can be used by routers, diskless workstations and centrally managed computers (thin clients) such as public computers at libraries and schools. Network booting can be used to centralize management of disk storage, which supporters claim can result in reduced capital and maintenance costs. It can also be used in cluster computing, in which nodes may not have local disks. In the late 1980s/early 1990s, network boot was used to save the expense of a disk drive, because a decently sized harddisk would still cost thousands of dollars, often equaling the price of the CPU. Hardware support Contemporary desktop personal computers generally provide an option to boot from the network in their BIOS/UEFI via the Preboot Execution Environment (PXE). Post-1998 PowerPC ( G3 G5) Mac systems can also boot from their New World ROM firmware to a network dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UDP/IP
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 this ... [...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 this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII
ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of technical limitations of computer systems at the time it was invented, ASCII has just 128 code points, of which only 95 are , which severely limited its scope. All modern computer systems instead use Unicode, which has millions of code points, but the first 128 of these are the same as the ASCII set. The Internet Assigned Numbers Authority (IANA) prefers the name US-ASCII for this character encoding. ASCII is one of the List of IEEE milestones, IEEE milestones. Overview ASCII was developed from telegraph code. Its first commercial use was as a seven-bit teleprinter code promoted by Bell data services. Work on the ASCII standard began in May 1961, with the first meeting of the American Standards Association's (ASA) (now the American Nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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