Hi, I having a problem with FTP service setup on Linux RedHat 8.0. I have do the necessary configuration according the samples that I have downloaded from few web sites. And I have verified that the FTP is working within office network (Eg. I can upload and download files from the RedHat 8.0 FTP server with > ftp 192.168.100.133)

But when I tried to access via Internet, it prompts me as follow:

C:\>ftp 203.xxx.xxx.xxx
Connected to 203.xxx.xxx.xxx
Connection closed by remote host.

It always said 'Connection closed by remote host'.
I have tried the possible which found on Internet but all failed.

Below is my /etc/vsftpd.conf file:

# Example config file /etc/vsftpd.conf
#
# The default compiled in settings are very paranoid. This sample file
# loosens things up a bit, to make the ftp daemon more usable.
#
# Allow anonymous FTP?
anonymous_enable=YES
#
# Uncomment this to allow local users to log in.
local_enable=YES
#
# Uncomment this to enable any form of FTP write command.
write_enable=YES
#
# Default umask for local users is 077. You may wish to change this to 022,
# if your users expect that (022 is used by most other ftpd's)
local_umask=022
#
# Uncomment this to allow the anonymous FTP user to upload files. This only
# has an effect if the above global write enable is activated. Also, you will
# obviously need to create a directory writable by the FTP user.
#anon_upload_enable=YES
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#anon_mkdir_write_enable=YES
#
# Activate directory messages - messages given to remote users when they
# go into a certain directory.
# dirmessage_enable=YES
#
# Activate logging of uploads/downloads.
xferlog_enable=YES
#
# Make sure PORT transfer connections originate from port 20 (ftp-data).
connect_from_port_20=YES
#
# If you want, you can arrange for uploaded anonymous files to be owned by
# a different user. Note! Using "root" for uploaded files is not
# recommended!
#chown_uploads=YES
#chown_username=whoever
#
# You may override where the log file goes if you like. The default is shown
# below.
xferlog_file=/var/log/vsftpd.log
#
# If you want, you can have your log file in standard ftpd xferlog format
xferlog_std_format=YES
#
# You may change the default value for timing out an idle session.
#idle_session_timeout=600
#
# You may change the default value for timing out a data connection.
#data_connection_timeout=120

# It is recommended that you define on your system a unique user which the
# ftp server can use as a totally isolated and unprivileged user.
#nopriv_user=ftpsecure
#
# Enable this and the server will recognise asynchronous ABOR requests. Not
# recommended for security (the code is non-trivial). Not enabling it,
# however, may confuse older FTP clients.
#async_abor_enable=YES
#
# By default the server will pretend to allow ASCII mode but in fact ignore
# the request. Turn on the below options to have the server actually do ASCII
# mangling on files when in ASCII mode.
# Beware that turning on ascii_download_enable enables malicious remote parties
# to consume your I/O resources, by issuing the command "SIZE /big/file" in
# ASCII mode.
# These ASCII options are split into upload and download because you may wish
# to enable ASCII uploads (to prevent uploaded scripts etc. from breaking),
# without the DoS risk of SIZE and ASCII downloads. ASCII mangling should be
# on the client anyway..
#ascii_upload_enable=YES
#ascii_download_enable=YES
#
# You may fully customise the login banner string:
ftpd_banner="FTP ready"
#
# You may specify a file of disallowed anonymous e-mail addresses. Apparently
# useful for combatting certain DoS attacks.
#deny_email_enable=YES
# (default follows)
#banned_email_file=/etc/vsftpd.banned_emails
#
# You may specify an explicit list of local users to chroot() to their home
# directory. If chroot_local_user is YES, then this list becomes a list of
# users to NOT chroot().
# chroot_local_user=NO
# chroot_list_enable=YES
# (default follows)
# chroot_list_file=/etc/vsftpd.chroot_list
#
# You may activate the "-R" option to the builtin ls. This is disabled by
# default to avoid remote users being able to cause excessive I/O on large
# sites. However, some broken FTP clients such as "ncftp" and "mirror" assume
# the presence of the "-R" option, so there is a strong case for enabling it.
#ls_recurse_enable=YES
pam_service_name=vsftpd
listen_port=21
local_root=/home/Asset
hide_ids=YES
log_ftp_protocol=YES

I have tried to solved this problem since one week ago. I have no idea what can I do now? Please help!! Thank you.

For those like me who did'nt find an answer in the forums

I had some similar problem with a machine on a dmz.
ftp access from lan worked but not from the internet.

the problem was the dns server in resolv.conf . it could not be reached from the dmz.
after correcting the adress , all worked as expected.
cheers

If it helps anyone - i was getting the immediate disconnect on vsftpd when trying to tunnel through putty:

C:\>ftp 203.xxx.xxx.xxx
Connected to 203.xxx.xxx.xxx
Connection closed by remote host.

I was using the external ip of the server I was trying to tunnel to - which didnt work as the server only had port 21 open locally. So I changed the putty tunnel ip to the private ip (192.168.1.x) of the server and it worked fine.