RFC 2428 (rfc2428) - Page 2 of 8
FTP Extensions for IPv6 and NATs
Alternative Format: Original Text Document
RFC 2428 FTP Extensions for IPv6 and NATs September 1998
This document provides a specification for a way that FTP can
communicate data connection endpoint information for network
protocols other than IPv4. In this specification, the FTP commands
PORT and PASV are replaced with EPRT and EPSV, respectively. This
document is organized as follows. Section 2 outlines the EPRT
command and Section 3 outlines the EPSV command. Section 4 defines
the utilization of these two new FTP commands. Section 5 briefly
presents security considerations. Finally, Section 6 provides
conclusions.
2. The EPRT Command
The EPRT command allows for the specification of an extended address
for the data connection. The extended address MUST consist of the
network protocol as well as the network and transport addresses. The
format of EPRT is:
EPRT
The EPRT command keyword MUST be followed by a single space (ASCII
32). Following the space, a delimiter character () MUST be
specified. The delimiter character MUST be one of the ASCII
characters in range 33-126 inclusive. The character "|" (ASCII 124)
is recommended unless it coincides with a character needed to encode
the network address.
The argument MUST be an address family number defined by
IANA in the latest Assigned Numbers RFC (RFC 1700 [RP94] as of the
writing of this document). This number indicates the protocol to be
used (and, implicitly, the address length). This document will use
two of address family numbers from [RP94] as examples, according to
the following table:
AF Number Protocol
--------- --------
1 Internet Protocol, Version 4 [Pos81a]
2 Internet Protocol, Version 6 [DH96]
The is a protocol specific string representation of the
network address. For the two address families specified above (AF
Number 1 and 2), addresses MUST be in the following format:
AF Number Address Format Example
--------- -------------- -------
1 dotted decimal 132.235.1.2
2 IPv6 string 1080::8:800:200C:417A
representations
defined in [HD96]
Allman, et. al. Standards Track