Thinstation по русски всё о лёгком подключении тонкого клиента

💻 How does TFTP Work?

TFT severs works in following method:

• The client requires to open server socket on server’s IP address on UDP port 69 as the server depend upon port 69 which helps to establish a UDP connection with the client.
• So, when the connection gets established, the client can send the message request to the server. There are various types of message requests can be sent to the server.
• For Example, the client send a Read Request (RRQ) if any file requires to be fetched from the server or Write Request (WRQ) to transfer any file over the network.
• Then TFTP server divides the message into blocks of 512 bytes. Here, the noticeable part is the last block of every file is lesser than 512 bytes. This helps the receiver to interpret the last block from the sender.
• After that, every block should be transferred as a TFTP data message, and all the remaining blocks are assigned with a TFTP number. However, each block should be kept separately inside a UDP message.
• So each time when the size of the last block would not always be less (except if it is multiple of 512), so the sending user sends another block of zero bytes that give message to the receiver that the transfer part is over.
• TFTP also follows check and pause protocol, therefore it sends each block one after one.
• When it sends the first block, it starts a present block timer. For the sent block, when the response from the server comes it received with the block timer.
• After that, the second block of the file is sent. However, in case of response is found by the server, then the first block of the file is sent. This is method that helps TFTP to achieves flow control.

Tftp сервер windows

Для того, чтобы развернуть сервер на своем рабочем месте необходимо:

Загрузить нужный дистрибутив отсюда

Стоит обратить внимание, что дистрибутивы различаются по типу запуска: как службу (service edition) и как приложение (standard edition) и также по битности ОС. Для себя я выбрал пакет tftpd64 service edition (installer)
После загрузки, устанавливаем загруженный дистрибутив, не изменяя абсолютно никаких параметров

Если Вы загрузили, как и я, дистрибутив с запуском в качестве службы, то стоит вручную запустить службу или просто перезапустить компьютер.

далее жмем i Agree и соглашаемся с лицензионным соглашением.

Выставляем нужный птички и жмем next.

Как установить tftp сервер на примере tftpd64 service edition-03

Задаем при необходимости альтернативный каталог для установки.

Как установить tftp сервер на примере tftpd64 service edition-04

Как установить tftp сервер на примере tftpd64 service edition-05

Как установить tftp сервер на примере tftpd64 service edition-06

Не забудьте проверить что открыт TCP, UPD порт 69.

Как установить tftp сервер на примере tftpd64 service edition-07

Открываем установленную программу и нажимаем снизу Settings

Как установить tftp сервер на примере tftpd64 service edition-08

Оставляем галку TFTP Server

Как установить tftp сервер на примере tftpd64 service edition-09

Переходим на вкладку TFTP и нажимаем Browse

Как установить tftp сервер на примере tftpd64 service edition-10

Указываем папку где у вас будет ссылка на папку tftp

Как установить tftp сервер на примере tftpd64 service edition-11

Закрываем, у вас должно получиться нечто подобное

Как установить tftp сервер на примере tftpd64 service edition-12

Всё! Теперь можно подключаться к серверу и копировать файлы. У операционной системы Windows XP tftp-клиент установлен по умолчанию, а у Windows server 2008R2 его необходимо доставить, я описал это тут (Как установить tftp клиента в Windows Server 2008R2)

Handling time-outs

According to RFC 1350,
both the client and the server should check for time-outs for the packets that
they transmit. The packets can be data packets or acknowledgements. For the
protocol, it is sufficient that only one side uses a time-out. A common
simplification is only data blocks time out. Acknowledgements are simply transmitted
once, and never re-transmitted.

In this scheme, if a data packet gets lost, it will be re-transmitted. If an
acknowledgement packet gets lost, the transmitter will not see an acknowledgement
for the data packet and it will re-transmit the data packet. The receiver receives
a duplicate packet, which it acknowledges again. In conformance with RFC 1350, a
transmitter must be prepared to receive a duplicate ACK.

This is purely an implementation issue. In addition, the two hosts do not need
to agree on how to handle time-outs: one host that re-transmits only data packets
can interoperate with another host that re-transmits both data and acknowledgement
packets.

WinAgents TFTP Server

WinAgents Software Group offers free downloads of their TFTP Server. It’s a legacy software designed to run on Windows 2000, 2003, Vista, and 7, which makes it useful if you work with these older OSes on your network. It can probably work with Windows 10 as well, you just need to try it.

WinAgents TFTP Server operates as a background service and implements an IP-based access control model for some kind of network security.

It also supports sending files through firewalls by configuring a UDP port for the connections. Administrators who manage large intranets or remote sites will find the remote configuration features helpful. The cache system makes the system highly scalable compared to other free TFTP tools.

TFTPD32/64

TFTPD32 or TFTPD64 is the 32-bit or 64-bit Windows version of a French open source network utility package that includes a TFTP server. The services provided in addition to the TFTP server include DHCP, Syslog server, log viewer etc. A TFTP client is also in the package if you need one to install on network devices receiving files.

TFTPD32/64 is the brainchild of Phillipe Jounin, who has made it available to the public under the European Union Public License. It’s been implemented in projects like Cisco’s PIX and Aironet, HP’s Alpha servers, and Juniper’s Netscreen. It also won CNET’s Five Star Award in 2009 and is probably the oldest utility of its kind.

Настройка и установка NFS в Fedora Core

1) Установка пакета

2) Настройка конфигурации В этом файле содержится описание директорий, которые будут доступны для монтирования по NFS:

Пример записи в файле »/etc/exports», позволяющий монтировать директорию с файловой системой для Embedded Linux:

rw — возможность чтения и записи содержимого директории no_root_squash — доступ к файлам с правами суперпользователя (root) no_all_squash — сохранение uids и gids пользователя файлам sync — NFS отвечает на запросы лишь после модификации файлов

3) Запуск службы NFS

Должны появится следующие надписи:

В случае, если NFS запускается в первый раз, то вместо «service nfs restart» необходимо написать «service nfs start». Процедуру «restart» необходимо выполянть каждый раз, когда вы меняете записи в »/etc/exports».

4) Проверка NFS Чтобы убедиться, что директории экспортированы, надо выполнить команду:

Если какие-либо директории из файла »/etc/exports» отсутствуют, то проверьте конфигурацию в файле.

5) Включение службы NFS

После выполнения этой команды NFS сервер будет стартовать автоматически для уровней выполнения 3, 4 и 5.

What is TFTP?

Current FTP sessions support a lot of different commands. While logged in to an FTP server, users can usually list, delete, rename, upload, or download files and change directories. In contrast, TFTP offers only the ability to upload or download a file and uses UDP over IP instead of the more standard TCP/IP stack.

The protocol is not capable of allowing more advanced functionality but compensates by using the lockstep method of fault-tolerance that makes it extremely reliable. Due to this limited functionality, TFTP servers can have an extremely small footprint on the disk as well as in memory, making it ideal for use in embedded network devices.

Linux is far and away the most common operating system on the type of devices where you’re likely to encounter a TFTP server. But, there is also a rich ecosystem of Windows and macOS devices that run device firmware (think Apple TVs and Microsoft Surface for a few examples).

See also:

• Best SCP servers
• Best SFTP servers

How to Check a TFTP Server from Windows 10 Client

Let’s assume that the TFTP server setup is done correctly and the network security firewall is accepting incoming and outgoing TFTP traffic in the server.

Once we installed the client on Windows 10 PC, we need to allow TFTP traffic in the Windows firewall or your third-party firewall/anti-virus solution.

1. You can altogether disable the Windows firewall to test it.
2. Allow the TFTP program or port number in the firewall.

How to Completely switch off the Windows Defender Firewall to allow TFTP

5) Go to the control panel, enable the ‘Large Icons’ view. This will show the all Control panel icon.

6) Click on ‘Windows Defender Firewall’ and open ‘Turn Windows Defender Firewall on or off.’

7) Depending on the connectivity type, you can turn off the Windows firewall. If you are not sure, turn off both (Private and Public network settings). This will entirely off the network protection. It is highly recommended to put back the settings once the TFTP test completed. Or else, follow the next step to enable only TFTP traffic.

[edit] Mac OS X

OS X ships with a command-line TFTP client.

First, download the firmware file and put it in your user folder (/Users/yourusername/).

Then connect your computer directly to your router via ethernet. Go to System Preferences > Network. Click on «Ethernet» in the left panel and change «Configure IPv4» to «Manually». Then change «IP address» to 192.168.1.x (where x is any number between 2 & 255).

Then copy & paste the following text into a text editor:

 connect 192.168.1.1
 binary
 rexmt 1
 timeout 60
 put dd-wrt.vXX_XXX.XXX

Change the last line to the filename of the firmware file, which you just moved to your user folder. Copy the whole thing, including the line break after the last line.

Now open Applications > Utilities > Terminal. Enter:

 tftp

A «tftp>» command prompt will appear. Now press the reset button on your router. On the tftp command line in Terminal, paste (Cmd+v) the text you copied. Since you copied the line break at the end, tftp will execute the command at the moment you paste it. Depending on your router, you may have to paste it multiple times to get the timing right.

If it works, you’ll see something like this:

 tftp> connect 192.168.1.1
 tftp> binary
 tftp> rexmt 1
 tftp> timeout 60
 tftp> put dd-wrt.vXX_XXX.XXX
 Sent 1769472 bytes in 9.0 seconds

Install TFTP Client

At this point, the TFTP server is installed and configured.

Now, you will need to install a TFTP Client on the Client computer.

You can install the TFTP Client on the client computer by following the below steps:

1. Click on the Start Menu and click on Control Panel.

2. Click on the Programs and Features => Turn Windows features on or off. This will open the Windows Features dialog box.

3. Scroll down until you see the TFTP Client check box and CHECK it as shown below:

4. Click on the OK button to start the installation process of the TFTP client.

This process will take some time to finish the installation. Once you are finished, you can proceed to the next step.

Final Words

TFTP is a terrific and often misunderstood transferring method.

Although it has a bad reputation for its lack of security, it doesn’t have much overhead, making it a reliable, quick, and easy transferring mechanism.

You can use it in enclosed LANs or WANs, where speed reigns over security.

Setting up a TFTP server on Windows 10 is straightforward. Just download Solarwinds TFTP Server and configure it, as shown in this tutorial.

If your TFTP client is a networking device, it will likely have the TFTP service already enabled. But if you want to transfer files to a Windows 10 workstation, you can enable the TFTP built-in feature.

We hope that this tutorial was informative.

Please comment if you have any questions about the setup and configuration of the TFTP on your Windows 10.

Configuring Firewall to Allow TFTP

Before using the TFTP client, you will need to turn off the Windows Firewall or configure the Firewall to allow the inbound/outbound transfer of files using the TFTP client.

You can follow the below steps to add an exception for the TFTP connections:

1. Go to the Start Menu and open the Control Panel as shown below:

2. Click on the Windows Firewall to open the firewall as shown below:

3. In the left-pane, click on the “Allow an app or feature through Windows Firewall“.

You should see the following page:

4. Click on the Allow an app or feature through Windows Firewall at the bottom. You should see the following page:

5. Click on the Browse button and specify the TFTP.EXE path and click on the Add button.

You should see the following page:

6. You should see that the Trivial File Transfer Protocol App should be highlighted.

7. Now, click on the OK button to finish the process.

At this point, your client computer is configured to allow PUT and GET command against your TFTP server.

Документация по стандартам IETF

Номер RFC	Заголовок	Опубликовано	Автор	Устаревшая и обновленная информация
RFC 783	Протокол TFTP (редакция 1)	Июнь 1981 г.	К. Соллинз	Устарело — RFC 1350
RFC 906	Загрузка начальной загрузки с использованием TFTP	Июнь 1984 г.	Росс Финлейсон	—
RFC 951	Протокол начальной загрузки	Сентябрь 1985 г.	Билл Крофт	Обновлено RFC 1395, RFC 1497, RFC 1532, RFC 1542, RFC 5494
RFC 1350	Протокол TFTP (Версия 2)	Июль 1992 г.	К. Соллинз	Обновлено RFC 1782, RFC 1783, RFC 1784, RFC 1785, RFC 2347, RFC 2348, RFC 2349
RFC 1782	Расширение опции TFTP	Март 1995 г.	Г. Малкин	Устарело — RFC 2347
RFC 2131	Протокол динамического конфигурирования сервера	Март 1997 г.	Р. Дромс	Обновлено RFC 3396, RFC 4361, RFC 5494, RFC 6842
RFC 2347	Расширение опции TFTP	Май 1998 г.	Г. Малкин	—
RFC 2348	Вариант размера блока TFTP	Май 1998 г.	Г. Малкин	—
RFC 2349	Интервал тайм-аута TFTP и параметры размера передачи	Май 1998 г.	Г. Малкин	—
RFC 5505	Принципы настройки Интернет-хоста	Май 2009 г.	Б. Абоба	—
RFC 7440	Вариант TFTP Windowsize	Январь 2015	П. Масотта	—

haneWin TFTP Server

haneWin TFTP Server is a shareware offering for Windows. It supports both current and legacy Windows versions ranging from XP to Windows 10, and it can run as a service in the background on Windows 95/98/2000 without a user account logged in.

Data security options provided by haneWin include profiles based on the operation requested, IP address, and the file directories used by the server.

You can configure the server to transfer data through a range of UDP ports depending on your firewall settings and network traffic.

The client that comes with haneWin’s TFTP server is a Win32 console app that implements TFTP configurations in its command line options. For instance, you can set up a pipeline that will direct file transfers to other applications.

Соображения безопасности

TFTP не включает механизмов входа в систему или контроля доступа

Необходимо соблюдать осторожность при использовании TFTP для передачи файлов, когда требуются аутентификация, контроль доступа, конфиденциальность или проверка целостности

Обратите внимание, что эти службы безопасности могут быть предоставлены выше или ниже уровня, на котором работает TFTP

Также необходимо проявлять осторожность в правах, предоставляемых процессу сервера TFTP, чтобы не нарушать безопасность файловой системы сервера. TFTP часто устанавливается с такими элементами управления, что только файлы с общедоступным доступом для чтения доступны через TFTP

Также обычно запрещены перечисление, удаление, переименование и запись файлов через TFTP. Передача файлов по TFTP не рекомендуется, если присущие протоколу ограничения могут вызвать непреодолимую ответственность.

TFTP часто устанавливается с такими элементами управления, что только файлы с общедоступным доступом для чтения доступны через TFTP. Также обычно запрещены перечисление, удаление, переименование и запись файлов через TFTP. Передача файлов по TFTP не рекомендуется, если присущие протоколу ограничения могут вызвать непреодолимую ответственность.

Альтернатива домашней сети

Домашняя группа Windows была удобным инструментом для обмена файлами по сети. Но была исключена с обновлением Windows 10 до версии 1803. Для замены можно использовать TFTP-сервер, который интуитивный в настройке, достаточно надежный и позволяет передавать данные на быстрой скорости.

Перед настройкой сервера TFTP нужно выполнить следующие действия:

1. Войдите в систему под учетной записью администратора.
2. Загрузите установщик TFTP-сервера компании SolarWinds. После распакуйте загруженный zip архив в любое место на диске и установите программу, следуя инструкциям на экране.
3. Чтобы разрешить удаленный доступ к серверу, нужно переадресовать UDP-порт 69 на IP адрес домашней сети. Но, если удаленное подключение не требуется, то переназначать порты не нужно.

Spiceworks TFTP Server

Spiceworks is a well-known networking and IT community with various relevant software tools as well.

One of their offerings include a network administration app that bundles a TFTP server for network configuration tasks.

The app includes an inventory tab that gives you a snapshot of all your network devices and workstations.

It includes an interface for scheduling file transfers like backups, configuration restore files, and firmware updates.

SpiceWorks also provides advanced features like comparing a device’s current software configuration with a backup to detect changes that have been made.

Whether you need to reset your workstations to a software configuration periodically or just want to schedule safe backups for repairing errors in the future, SpiceWorks can handle your TFTP server needs.

You will need to register and create an account in order to download.

How to set up a TFTP server on Fedora

Contribute at the Fedora CoreOS Test Day

TFTP, or Trivial File Transfer Protocol, allows users to transfer files between systems using the UDP protocol. By default, it uses UDP port 69. The TFTP protocol is extensively used to support remote booting of diskless devices. So, setting up a TFTP server on your own local network can be an interesting way to do Fedora installations, or other diskless operations.

TFTP can only read and write files to or from a remote system. It doesn’t have the capability to list files or make any changes on the remote server. There are also no provisions for user authentication. Because of security implications and the lack of advanced features, TFTP is generally only used on a local area network (LAN).

Handling large files

The basic TFTP protocol works with packets with 512 bytes of data —with an exception
for the final block of the transfer. Each packet contains a 16-bit block counter and
this counter starts at 1 (one) for the first block. As long as the data to transfer
is less than 65535 blocks (the highest value for a 16-bit counter), all is well.
This sums up to (nearly) 32 MiB.

For bigger files, there are three options: larger TFTP data blocks, allowing the
block counter to roll over and concatenation of separate transfers to a single file.

• Larger data blocks

  RFC 2348
  defines an extension for larger block sizes. Even though the RFC allows blocks of up to
  65464 bytes, in practice the limit is set to 1468 bytes: the size of an Ethernet
  MTU minus the headers of TFTP (4 bytes), UDP (8 bytes) and IP (20 bytes). Larger
  packets run a high risk of being fragmented at the IP level, and this is generally
  considered a bad thing. With a block size of 1468 bytes, the maximum
  transfer size is over 91 MiB. Increasing the block size improves the transfer
  performance at the same time as allowing larger files to be transferred.

  Next to the standard «blksize» option, there is also a non-standard «blksize2»
  option. The latter has the restriction that the block size must be a power of
  two (512, 1024, 2048, …). The server should not use a block size below 512
  bytes unless a client has explicitly requested it.

• Block counter roll-over

  RFC 1350 does not mention block counter roll-over, but several TFTP hosts implement
  the roll-over be able to accept transfers of unlimited size. There is no consensus,
  however, whether the counter should wrap around to zero or to one. Many implementations
  wrap to zero, because this is the simplest to implement. The
  «ARINC 615A
  Data Load Protocol» mandates a roll-over to 1.

  Although the block counter roll-over does not need a change in (or extension of)
  the TFTP protocol per se, it does require that both host agree on the
  method of rolling over. While many TFTP hosts use block counter roll-over implicitly,
  it should be an option in the TFTP option negotiation. I propose the option name
  «rollover» for this purpose. The client sets this option if it supports block counter
  roll-over, and it indicates whether it wants to wrap to zero or wrap to one. The
  server acknowledges this option if it supports roll-over and the method.

• Collect separate TFTP transfers into a single file

  Instead of requesting full files, a client could ask the server to transfer
  part of a file. The client sets the offset from the beginning of the file through
  an option. The server acknowledges the option if it supports it. The «toffset»
  option would normally be combined with the «tsize» option to set both the start
  offset and the amount of data to transfer. The «toffset» option is my proposal;
  «tsize» is a standard option defined in
  RFC 2349.

Настройка сервера TFTP

Если разрешили доступ к TFTP-серверу за пределами локальной сети дома, офиса и другого места, проверьте, что статический или динамический IP добавлен в диапазон адресов. По умолчанию на сервере разрешены все IP адреса для передачи и получения файлов, а также перенаправление портов. Можно ограничить диапазон IP, чтобы разрешить только несколько адресов.

Для настройки сервера следуйте инструкции:

1. После запуска утилиты SolarWinds TFTP Server, перейдите в File — Configure. Для отображения иконки в правом нижнем углу на панели задач отметьте флажком поле «Добавить сервер в системный трей Windows».
2. Выберите корневой каталог сервера. В нем будут храниться все отправленные и принятые файлы. Чтобы передать файлы, их нужно будет скопировать в этот каталог.
3. Перейдите на вкладку Безопасность, чтобы ввести некоторые ограничения. Здесь можно включить прием или передачу, разрешить определенный диапазон IP или только один адрес.
4. После нажмите на ОК, чтобы сохранить настройки, и закрыть окно конфигурации.

Allow TFTP Protocol in Windows 10 Firewall

Let’s assume you use multiple tools and programs which use the TFTP protocol. It is not advisable to follow the earlier step and add each program in the firewall. Instead of that, we can add the common TFTP protocol which usually used in all the TFTP programs.

TFTP uses port 69. We will simply enable this port in incoming and outgoing traffic.

12) In the usual Windows defender firewall settings page, click on ‘Advanced Settings.’

13) In the ‘Inbound Rules’ create a new rule.

14) Select ‘Port’ and enter 69 as TCP port.

15) Make sure that ‘Allow the connection’ is selected on the next screen, select all 3 network types.

16) Give a name to the rule and press OK.

17) Make sure it is enabled and listed in ‘Inbound Rules’.

18) Repeat the same steps in ‘Outbound Rules’

With these above steps, your client Windows 10 PC is ready to use the TFTP client.

Best TFTP server

Name	IPv4/IPv6	File Size Limit	Link
SolarWinds Free TFTP server	IPv4	4 GB	Learn More
Spiceworks TFTP server	IPv4	33 MB	Learn More
Progress WhatsUp TFTP Server	IPv4	4 GB	Learn More

1) SolarWinds Free TFTP server

SolarWinds provides a free TFTP server for Windows that offers basic functionalities like IP-range lockdown, etc. It can transfer files up to 4GB in size. This server management service is easier to manage with native Windows tools.

Key Features:

• Suitable for transferring device configuration images
• Communicates with several devices simultaneously
• It offers concurrent transfers from multiple devices and runs as a Windows service.
• Let’s you authorize a specific IP address or a range of IPs altogether.
• Easy to use TFTP software with backup network devices and configurations.
• Offers highly scalable multi-user administration and advanced device config backup.
• Free TFTP server which runs on Windows easily

2) Spiceworks TFTP server

Spiceworks is a complete IT management tool that provides its users with free TFTP servers to make their work easy.

This TFTP software is one of the best TFTP servers developed for IT professionals to track their network device config. It also enables you to backup and view all your config in one place.

Features

• Allows you to compare current network configration with backups.
• These TFTP servers can be used for configuration image transfers
• Helps you to push out firmware updates in the background.
• Free and in-built features of Spiceworks.

Link: https://www.spiceworks.com/free-tftp-server-for-network-configuration-management/

3) Progress WhatsUp TFTP Server

WhatsUp Gold is one of the best TFTP servers, which helps save you time while doing networking. This service-based tool allows you to securely transfer files across the network.

Features:

• It offers a simple transfer of system configuration.
• Sturdy, clean, and attractive GUI based interface.
• It helps you to save time and effort when uploading and downloading the file.
• Compatible with the older versions of Windows such as XP, Vista, and others.

Link:https://www.whatsupgold.com/free-network-monitoring-tools/free-tftp-server

4) TFTP Desktop Server

TFTP desktop server is the best solution for updating routers, OS, image transfer, and remote booting. It also allows you to configure multiple devices in a single network.

Features:

• Real-time TFTP graph transfer helps you to work across the network.
• Unlimited file sizes: no 16/32MB file size limitation
• Graphs TFTP transfers in real-time
• Directory and IP address-based security
• Secured and locked TFTP root folder
• It offers security based on the directory as well as the IP address.
• Extremely fast file transfers

Link:https://tftp-desktop-server.apponic.com/

5) WinAGents

WinAgents provides a fully recognized TFTP server. It is a specially built tool to work consistently in the background. It helps you to create stock copies of different data like flash images, config files, and device settings in case of an emergency.

Features:

• Offers virtual TFTP folders, servers, and graphic utilities for status control.
• Offers highly scalable server architecture that has a built-in cache system and remote server administration.
• It helps you to set different access rights for various folders.
• It provides an option for setting the highest precedence for the server process
• Provide IP based access control
• File transmission using firewalls, and high precedence for a server process.

Link:https://www.winagents.com/en/products/tftp-server/

6) atftpd

ATFTPD is a Windows TFTF server that is widely used in various types of networks. It offers multithreaded and multicast architecture.

Features:

• Full TFTP options support with high compatibility options.
• It also supports PXE or MTFTP specifications.
• Provides fast servers to make your packages search as fast as possible.
• It helps you to replace the requested filename with the new one.
• Allows users to restrict accessing the untrusted hosts.
• Free TFTP Server for Linux.

Link: https://pkgs.org/download/atftpd

7) haneWIN TFTP server

haneWIN TFTP is a multithreaded server-based and fully realizable TFTP server for all versions of Windows. This TFTP server for Windows helps you to achieve maximum reliability and high performance while transferring the data.

Features:

• Implemented as a Windows service and also supports all types of Windows versions.
• This TFTP server for Windows includes an intuitive control panel for accessing all services.
• Offers multithreaded architecture for high performance, security, and reliability as well.
• It helps you to receive data directly into another application using a pipe option.

Link: https://www.hanewin.net/tftp-e.htm