FTP Operation Over Big Address Records (FOOBAR)
RFC 1639
Document | Type |
RFC - Experimental
(June 1994; No errata)
Obsoletes RFC 1545
|
|
---|---|---|---|
Author | David Piscitello | ||
Last updated | 2013-03-02 | ||
Stream | Legacy | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | Legacy state | (None) | |
Consensus Boilerplate | Unknown | ||
RFC Editor Note | (None) | ||
IESG | IESG state | RFC 1639 (Experimental) | |
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group D. Piscitello Request for Comments: 1639 Core Competence, Inc. Obsoletes: 1545 June 1994 Category: Experimental FTP Operation Over Big Address Records (FOOBAR) Status of this Memo This memo defines an Experimental Protocol for the Internet community. This memo does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited. Abstract This paper describes a convention for specifying address families other than the default Internet address family in FTP commands and replies. Introduction In the File Transfer Protocol (STD 9, RFC 959), the PORT command argument <host-port> specifies the data port to be used to establish a data connection for FTP (STD 9, RFC 959). This argument is also used in the PASV reply to request the server-DTP to listen on a data port other than its default data port. This RFC specifies a method for assigning addresses other than 32-bit IPv4 addresses to data ports through the specification of a "long Port (LPRT)" command and "Long Passive (LPSV)" reply, each having as its argument a <long- host-port>, which allows for additional address families, variable length network addresses and variable length port numbers. This is a general solution, applicable for all "next generation" IP alternatives, as well as for other network protocols than IP. This revision also extends FTP to allow for its operation over transport interfaces other than TCP. Acknowledgments Many thanks to all the folks in the IETF who casually mentioned how to do this, but who left it to me to write this RFC. Special thanks to Rich Colella, Bob Ullmann, Steve Lunt, Jay Israel, Jon Postel, Shawn Ostermann, and Tae Kyong Song, who contributed to this work. Piscitello [Page 1] RFC 1639 FTP Over Big Address June 1994 1. Background The PORT command of File Transfer Protocol allows users to specify an address other than the default data port for the transport connection over which data are transferred. The PORT command syntax is: PORT <SP> <host-port> <CRLF> The <host-port> argument is the concatenation of a 32-bit internet <host-address> and a 16-bit TCP <port-address>. This address information is broken into 8-bit fields and the value of each field is transmitted as a decimal number (in character string representation). The fields are separated by commas. A PORT command is thus of the general form "PORT h1,h2,h3,h4,p1,p2", where h1 is the high order 8 bits of the internet host address. The <host-port> argument is also used by the PASV reply, and in certain negative completion replies. To accommodate larger network addresses anticipated for all IP "next generation" alternatives, and to accommodate FTP operation over network and transport protocols other than IP, new commands and reply codes are needed for FTP. 2. The LPRT Command The LPRT command allows users to specify a "long" address for the transport connection over which data are transferred. The LPRT command syntax is: LPRT <SP> <long-host-port> <CRLF> The <long-host-port> argument is the concatenation of the following fields; o an 8-bit <address-family> argument (af) o an 8-bit <host-address-length> argument (hal) o a <host-address> of <host-address-length> (h1, h2, ...) o an 8-bit <port-address-length> (pal) o a <port-address> of <port-address-length> (p1, p2, ...) The initial values assigned to the <address-family> argument take the value of the version number of IP (see Assigned Numbers, STD 2, RFC 1340); values in the range of 0-15 decimal are thus reserved for IP Piscitello [Page 2] RFC 1639 FTP Over Big Address June 1994 and assigned by IANA. Values in the range 16-255 are available for the IANA to assign to all other network layer protocols over which FTP may be operated. Relevant assigned <address-family> numbers for FOOBAR are: Decimal Keyword ------ ------- 0 reserved 1-3 unassigned 4 Internet Protocol (IP) 5 ST Datagram Mode 6 SIP 7 TP/IX 8 PIP 9 TUBA 10-14 unassigned 15 reserved 16 Novell IPX The value of each field is broken into 8-bit fields and the value of each field is transmitted as an unsigned decimal number (in character string representation, note that negative numbers are explicitly notShow full document text