SuSe Linux：ftp 500 OOPS: could not bind listening IPv4 socket

        往一台Suse Linux 9 ftp文件时，发现报错：500 OOPS：could not bind listening IPv4 socket，如下所示：
SuSe9#ftp 10.10.10.10Connected to localhost.
500 OOPS: could not bind listening IPv4 socket
检查vsftpd状态，可知已启用，如下所示：
SuSe9#chkconfig --list vsftpd
xinetd based services:
        vsftpd:             on
Suse Linux vsftpd服务默认是在xinetd模式下运行，检查/etc/vsftpd.conf文件可发现，listen=YES前面的#号符已去掉，即开启vsftpd运行在standalone模式（见以下红色部分），以下为完整的vsftpd.conf文件配置：
SuSe9#cat vsftpd.conf
# Example config file /etc/vsftpd.conf
#
# The default compiled in settings are fairly paranoid. This sample file
# loosens things up a bit, to make the ftp daemon more usable.
# Please see vsftpd.conf.5 for all compiled in defaults.
#
# If you do not change anything here you will have a minimum setup for an
# anonymus FTP server.
#
# READ THIS: This example file is NOT an exhaustive list of vsftpd options.
# Please read the vsftpd.conf.5 manual page to get a full idea of vsftpd's
# capabilities.
# General Settings
#
# Uncomment this to enable any form of FTP write command.
#
write_enable=YES
#
# Activate directory messages - messages given to remote users when they
# go into a certain directory.
#
dirmessage_enable=YES
#
# 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
#
# You may fully customise the login banner string:
#
ftpd_banner="Welcome to FOOBAR FTP service."
#
# 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
#
# 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
#
# If  enabled,  all  user  and  group  information in
# directory listings will be displayed as "ftp".
#
#hide_ids=YES
# Local FTP user Settings
#
# Uncomment this to allow local users to log in.
#
local_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 to put local users in a chroot() jail in their home directory
# after login.
#
#chroot_local_user=YES
#
# 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_list_enable=YES
#
# (default follows)
#
#chroot_list_file=/etc/vsftpd.chroot_list
#
# The maximum data transfer rate permitted, in bytes per second, for
# local authenticated users. The default is 0 (unlimited).
#
#local_max_rate=7200

# Anonymus FTP user Settings
#
# Allow anonymous FTP?
#
#anonymous_enable=YES
#
# Anonymous users will only be allowed to download files which are
# world readable.
#
#anon_world_readable_only=YES
#
# 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
#
# Default umask for anonymus users is 077. You may wish to change this to 022,
# if your users expect that (022 is used by most other ftpd's)
#
#anon_umask=022
#
# Uncomment this if you want the anonymous FTP user to be able to create
# new directories.
#
#anon_mkdir_write_enable=YES
#
# Uncomment this to enable anonymus FTP users to perform other write operations
# like deletion and renaming.
#
#anon_other_write_enable=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
#
# The maximum data transfer rate permitted, in bytes per second, for anonymous
# authenticated users. The default is 0 (unlimited).
#
#anon_max_rate=7200

# Log Settings
#
# Log to the syslog daemon instead of using an logfile.
#
syslog_enable=YES
#
# Uncomment this to log all FTP requests and responses.
#
log_ftp_protocol=YES
#
# Activate logging of uploads/downloads.
#
xferlog_enable=YES
#
# You may override where the log file goes if you like. The default is shown
# below.
#
vsftpd_log_file=/var/log/vsftpd.log
#
# If you want, you can have your log file in standard ftpd xferlog format.
# Note: This disables the normal logging unless you enable dual_log_enable below.
#
xferlog_std_format=YES
#
# You may override where the log file goes if you like. The default is shown
# below.
#
xferlog_file=/var/log/xferlog
#
# Enable this to have booth logfiles. Standard xferlog and vsftpd's own style log.
#
dual_log_enable=YES
#
# Uncomment this to enable session status information in the system process listing.
#
#setproctitle_enable=YES
# Transfer Settings
#
# Make sure PORT transfer connections originate from port 20 (ftp-data).
#
connect_from_port_20=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
#
# 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
#
# Set to NO if you want to disallow the  PASV  method of obtaining a data
# connection.
#
#pasv_enable=NO
# PAM setting. Do NOT change this unless you know what you do!
#
pam_service_name=vsftpd
# Set listen=YES if you want vsftpd to run standalone
#
listen=YES
把listen=YES关闭，即把“listen=YES”修改为“#listen=YES”后ftp恢复正常，如下所示：
Suse9#ftp 10.10.10.10 Connected to gdCMs2.
220 "Welcome to FOOBAR FTP service."
Name (10.10.10.10:root):