Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide


NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

Read offline with no ads or diagram watermarks!
The TCP/IP Guide

Custom Search







Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP File and Message Transfer Applications and Protocols (FTP, TFTP, Electronic Mail, USENET, HTTP/WWW, Gopher)
                9  TCP/IP General File Transfer Protocols (FTP and TFTP)
                     9  Trivial File Transfer Protocol (TFTP)

Previous Topic/Section
TFTP Detailed Operation and Messaging
Previous Page
Pages in Current Topic/Section
123
4
Next Page
TFTP Message Formats
Next Topic/Section

TFTP Options and Option Negotiation
(Page 4 of 4)

TFTP Write Process With and Without Option Negotiation

The initial message exchange for a normal write (without option negotiation):

  1. Client sends write request.

  2. Server sends acknowledgment.

  3. Client sends data block #1.

  4. Server acknowledges data block #1.

And a write with option negotiation:

  1. Client sends write request with options.

  2. Server sends option acknowledgment (instead of regular acknowledgment).

  3. Client sends data block #1.

  4. Server acknowledges data block #1.
TFTP Options

Table 234 contains a summary of the three TFTP options currently defined.


Table 234: TFTP Options

TFTP Option Name

TFTP Option Code (Used in Request Messages)

Defining RFC

Description

Block Size

blksize

2348

Allows the client and server to send data blocks of a size different than 512 bytes, to improve efficiency or address limitations of a particular type of network.

Timeout Interval

interval

2349

Permits the client and server to agree on a specified number of seconds to use for their retransmission timers. Again, may be of value on certain networks with high latency or other special requirements.

Transfer Size

tsize

2349

Lets the device sending the file (client on a write, server on a read) tell the other device the size of the file before the transfer commences. This allows the receiving device to allocate space for it in advance.


Previous Topic/Section
TFTP Detailed Operation and Messaging
Previous Page
Pages in Current Topic/Section
123
4
Next Page
TFTP Message Formats
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005

© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.