| TFTP, Trivial File Transfer Protocol |
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Description | Glossary | RFCs | Publications | Obsolete RFCs |
| Protocol suite: | TCP/IP. |
| Protocol type: | Application layer file transfer protocol. |
| Multicast addresses: | |
| Ports: | 69 (UDP) server.
1758 (UDP) multicast. |
| URI: | tftp:. |
| MIME subtype: | |
| SNMP MIBs: | |
| Working groups: | tftpexts, TFTP Extensions. |
| Links: |
TFTP 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-byte blocksize is not the most efficient for use on a LAN whose MTU may 1500 bytes or greater.
| MAC header | IP header | UDP header | TFTP header | Data ::: |
TFTP header:
| 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Opcode | Data ::: | ||||||||||||||||||||||||||||||
Opcode.
16 bits, unsigned.
Specifies the format of the TFTP message.
| Opcode | Description | References |
|---|---|---|
| 1 | RRQ. Read request. | RFC 1350, RFC 2090 |
| 2 | WRQ. Write request. | RFC 1350 |
| 3 | DATA. Read or write the next block of data. | RFC 1350 |
| 4 | ACK. Acknowledgment. | RFC 1350 |
| 5 | ERROR. Error message. | RFC 1350 |
| 6 | OACK. Option acknowledgment. | RFC 2347 |
Error codes:
| Error | Description | References |
|---|---|---|
| 0 | No error. | |
| 1 | File not found. | |
| 2 | Access violation. | |
| 3 | Disk full or allocation exceeded. | |
| 4 | Illegal TFTP operation. | |
| 5 | Unknown transfer ID. | |
| 6 | File already exists. | |
| 7 | No such user. | |
| 8 | Terminate transfer due to option negotiation. | RFC 2347 |
RFCs:
[IEN 133] The TFTP Protocol.
[RFC 906] Bootstrap Loading using TFTP.
[RFC 1123] Requirements for Internet Hosts -- Application and Support.
[RFC 1350] THE TFTP PROTOCOL (REVISION 2).
[RFC 1785] TFTP Option Negotiation Analysis.
[RFC 2090] TFTP Multicast Option.
[RFC 2347] TFTP Option Extension.
[RFC 2348] TFTP Blocksize Option.
[RFC 2349] TFTP Timeout Interval and Transfer Size Options.
[RFC 3617] Uniform Resource Identifier (URI) Scheme and Applicability Statement for the Trivial File Transfer Protocol (TFTP).
[RFC 783] THE TFTP PROTOCOL (REVISION 2).
[RFC 1782] TFTP Option Extension.
[RFC 1783] TFTP Blocksize Option.
[RFC 1784] TFTP Timeout Interval and Transfer Size Options.
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Description | Glossary | RFCs | Publications | Obsolete RFCs |