KB Article #176306

EPSV (extended passive mode) in Gateway

Problem

-- Does Gateway support EPSV (extended passive) mode for FTP transfers?

Resolution


* In 6.14.1 and earlier versions, if a client connecting to Gateway issues an EPSV command, Gateway will reply with a 500 error ("command not understood"), and it will be up to the client to retry using regular passive mode (PASV).

* In 6.15.0 and later versions, Gateway does understand the EPSV command. If the connection is IPv6, it will respond with the format given in RFC 2428:

229 Entering extended passive mode (|||12345|)

otherwise it will respond similar to how it does to PASV:

229 Entering extended passive mode (1,2,3,4,5,6)

Note that not all clients will accept the latter form; some of them may disconnect when receiving such a response. In particular, if you use cURL to connect to Gateway over IPv4, you will need to use the --disable-epsv option to force cURL to use PASV.