Date: Sun, 24 Mar 2002 16:39:34 +0100 From: "Rick Hoppe" <mailing@rickhoppe.nl> To: <freebsd-questions@FreeBSD.org> Subject: FreeBSD base ftp client does not support PASV Message-ID: <MLECKHBMGODPBDHNOIAAAEBJDAAA.mailing@rickhoppe.nl>
next in thread | raw e-mail | index | archive | help
Hi, This weekend I learned that the ftp client that comes with FreeBSD does not support passive mode (PASV) but always uses extended passive mode (EPSV). Even when you use 'ftp -p' or 'pftp' to force passive mode, when you do a tcpdump, the ftp client submittes a EPSV command. This is problematic when you use a firewall with restrictive outbound connections, like I do. In that case you need a ftp proxy that handles EPSV or otherwise a third-party ftp client that supports PASV. I learned that IPNAT's proxy does not handle EPSV, so that's the reason why the ftp client doesn't work here. I simply get a connection refused. What I do not understand is that, although the man page for the ftp client /usr/bin/ftp says it supports passive ftp, it just don't. Is it a documentation problem, or a programming issue? Below you can find a part of the tcpdump output when issuing a 'ftp -p ftp://ftp.freebsd.org' from a FreeBSD 4.-5R system. Regards, Rick Hoppe Network- and Systemspecialist Xtraxion Internet 16:29:42.510419 xxxxxxx.xxxxxxxx.xxx.2746 > ftp.beastie.tdk.net.ftp: P 58:64(6) ack 1227 win 33304 <nop,nop,timestamp 37284028 23672775> (DF) [tos 0x10] 0x0000 4510 003a 5ace 4000 4006 4eb9 0a00 0002 E..:Z.@.@.N..... 0x0010 3ef3 4832 0aba 0015 cdaa 7080 eaec f63c >.H2......p....< 0x0020 8018 8218 6f76 0000 0101 080a 0238 e8bc ....ov.......8.. 0x0030 0169 37c7 4550 5356 0d0a .i7.EPSV.. 16:29:42.585108 ftp.beastie.tdk.net.ftp > xxxxxxx.xxxxxxxx.xxx.2746: P 1227:1275(48) ack 64 win 33304 <nop,nop,timestamp 23672783 37284028> (DF) [tos 0x10] 0x0000 4510 0064 fc49 4000 3106 bc13 3ef3 4832 E..d.I@.1...>.H2 0x0010 0a00 0002 0015 0aba eaec f63c cdaa 7086 ...........<..p. 0x0020 8018 8218 0196 0000 0101 080a 0169 37cf .............i7. 0x0030 0238 e8bc 3232 3920 456e 7465 7269 6e67 .8..229.Entering 0x0040 2045 7874 656e 6465 6420 5061 7373 6976 .Extended.Passiv 0x0050 6520 4d6f 6465 2028 7c7c 7c35 3033 3033 e.Mode.(|||50303 0x0060 7c29 0d0a |).. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?MLECKHBMGODPBDHNOIAAAEBJDAAA.mailing>