RFC 2348 (rfc2348) - Page 1 of 5
TFTP Blocksize Option
Alternative Format: Original Text Document
Network Working Group G. Malkin
Request for Commments: 2348 Bay Networks
Updates: 1350 A. Harkin
Obsoletes: 1783 Hewlett Packard Co.
Category: Standards Track May 1998
TFTP Blocksize Option
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Abstract
The Trivial File Transfer Protocol [1] is a simple, lock-step, file
transfer protocol which allows a client to get or put a file onto a
remote host. One of its primary uses is the booting of diskless
nodes on a Local Area Network. TFTP is used because it is very
simple to implement in a small node's limited ROM space. However,
the choice of a 512-octet blocksize is not the most efficient for use
on a LAN whose MTU may 1500 octets or greater.
This document describes a TFTP option which allows the client and
server to negotiate a blocksize more applicable to the network
medium. The TFTP Option Extension mechanism is described in [2].
Blocksize Option Specification
The TFTP Read Request or Write Request packet is modified to include
the blocksize option as follows. Note that all fields except "opc"
are NULL-terminated.
+-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
| opc |filename| 0 | mode | 0 | blksize| 0 | #octets| 0 |
+-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
opc
The opcode field contains either a 1, for Read Requests, or 2,
for Write Requests, as defined in [1].
Malkin & Harkin Standards Track