Affiliation
American Association of Variable Star Observers (AAVSO)
Fri, 03/18/2022 - 20:01
The AAVSOnet server recently moved to the AWS Cloud. It appears that FileZilla users need to make a bit of a tweak. Here is what I found to work in my site manager definition accessed via File->Site Manager...
I hope this helps. If not, let me know
Cliff
I also started to encounter issues with AAVSONet FTP server. I'm retrieving the data from ftp.aavsonet.aavso.org using Linux program lftp, that one allows to mirror the FTP server directory. The program logs in successfully but fails to create data connection. Cliff pointed out some settings he had to set for FileZilla: anonymous FTP ones are standard (and FTP is not using encryption, right?), but there is a troublesome one - Active mode FTP. That one definitely works, BUT, it very often fails when client is behind a firewall or NAT device (as many-many people in the world). Nowadays, the passive mode (PASV) FTP would be much better option.
Could anyone please point to the information what functionality is required from a FTP client for renewed AAVSONet FTP site?
Best wishes,
Tõnis, ETOA
I did some tests - seems that AAVSONet FTP server in AWS Cloud is supporting only active mode FTP, which is rather uncommon nowadays. As Cliff pointed out, he had to change from almost always used FTP passive mode to active mode, to recveive the data.
While active mode FTP may work for many (but most probably not for all) home users, people behind many firewalls (without NAT) and some NAT devices just can't use that - reverse connection from ftp.aavsonet.aavso.org to computers of such users can't be (well, is impossible to be) established. Would it be possible to enable passive mode FTP again (as most FTP servers nowadays have and what is default mode probably for almost all FTP client programs) on that FTP server?
It can be done in ProFTP server (AAVSONet FTP is using that one) as described e.g. there:
https://support.hostway.com/hc/en-us/articles/360000563730-How-to-enable-passive-FTP-connections-in-ProFTPD
Internet search for: ProFTP server passive mode aws
should give good examples how to do that.
The issue itself is described with graphical representation in: https://docs.cpanel.net/knowledge-base/ftp/how-to-enable-ftp-passive-mode/
Best wishes,
Tõnis, ETOA
Results of my tests to illustrate the issue:
This is how that looks behind an university NAT + Firewall:
[tonis@hermes2 BSM]$ ftp ftp.aavsonet.aavso.org
Connected to ftp.aavsonet.aavso.org (3.229.152.127).
220 ProFTPD Server (parsimony) [::ffff:172.31.22.6]
Name (ftp.aavsonet.aavso.org:tonis): anonymous
331 Anonymous login ok, send your complete email address as your password
Password:
230-Welcome to the AAVSOnet image archive!
230-
230-The local time is: Thu Mar 24 10:47:08 2022
230-
230-If you have any unusual problems, please report them via e-mail to .
230 Anonymous access granted, restrictions apply
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> dir <============ stalled till timeout
227 Entering Passive Mode (172,31,22,6,160,75).
^C
receive aborted
waiting for remote to finish abort
ftp> pass <============ switching to active mode
Passive mode off.
ftp> dir
200 PORT command successful
425 Unable to build data connection: No route to host <============ can't work by definition because of active mode FTP
ftp>
And now how that looks from a computer with public IP-address and no firewall at all (which is extremely uncommon nowadays):
17:50:26 tonis@hermes:~ >ftp ftp.aavsonet.aavso.org
Connected to ftp.aavsonet.aavso.org (3.229.152.127).
220 ProFTPD Server (parsimony) [::ffff:172.31.22.6]
Name (ftp.aavsonet.aavso.org:tonis): anonymous
331 Anonymous login ok, send your complete email address as your password
Password:
230-Welcome to the AAVSOnet image archive!
230-
230-The local time is: Thu Mar 24 10:50:37 2022
230-
230-If you have any unusual problems, please report them via e-mail to .
230 Anonymous access granted, restrictions apply
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> dir <============ again stalled till timeout
227 Entering Passive Mode (172,31,22,6,163,29).
^C
receive aborted
waiting for remote to finish abort
ftp> pass <============ switching to active mode
Passive mode off.
ftp> dir
200 PORT command successful
150 Opening ASCII mode data connection for file list
drwxrwsr-x 51 ftp ftp 4096 Mar 23 20:05 aavsonet
-rwxrwsr-x 1 ftp ftp 157 Dec 19 21:05 welcome.msg
226 Transfer complete <============ Success! Because FTP server can connect to my computer directly...
ftp>
Tõnis,
I will look into this. In the mean time, it looks like "ftp" will work for you as a work around. Is that the case?
thanks
Cliff
Passive mode is enabled. It works for me with the linux "ftp" program. Please let me know if you have any other issues.
Cliff
now it works…
Hello Cliff,
now it works well! Thank you so much!
FTP would work, but even with graphical client it would involve too much manual work and is a bit prone to errors. Therefore I'm using a well-scriptable command-line FTP client lftp to mirror (without deletion on my side) the files under my directory in AAVSONet FTP server into my local computer's disk. It's just a simple shell script. I'll put it down here, maybe it is useful for someone else as well (replaced for forum values of PASS, LCD, and RCD with capitalized placeholders).
Best wishes,
Tõnis
#!/bin/bashHOST="ftp.aavsonet.aavso.org"
USER="anonymous"
PASS="MYPASS"
FTPURL="ftp://$USER:$PASS@$HOST"
LCD="/MY/LOCAL/DIRECTORY/FOR/FILES"
RCD="/aavsonet/MYDIR"
#DELETE="--delete"
#REVERSE="--reverse"
lftp -c "set ftp:list-options -a;
open '$FTPURL';
lcd $LCD;
cd $RCD;
mirror $REVERSE \
$DELETE \
--verbose"