proftpd 에서 로그인 상태를 유지하려면?

#
# /etc/proftpd/proftpd.conf -- This is a basic ProFTPD configuration file.
# To really apply changes reload proftpd after modifications.
#
 
# Includes DSO modules
Include /etc/proftpd/modules.conf
 
# Set off to disable IPv6 support which is annoying on IPv4 only boxes.
UseIPv6                         on
 
ServerName                      "Debian"
ServerType                      standalone
DeferWelcome                    off
 
MultilineRFC2228                on
DefaultServer                   on
ShowSymlinks                    on
 
TimeoutNoTransfer               600
TimeoutStalled                  600
TimeoutIdle                     1200
 
DisplayLogin                    welcome.msg
DisplayFirstChdir               .message
ListOptions                     "-l -L"
 
DenyFilter                      \*.*/
 
# Port 21 is the standard FTP port.
Port                            21
 
# In some cases you have to specify passive ports range to by-pass
# firewall limitations. Ephemeral ports can be used for that, but
# feel free to use a more narrow range.
# PassivePorts                    49152 65534
 
# To prevent DoS attacks, set the maximum number of child processes
# to 30.  If you need to allow more than 30 concurrent connections
# at once, simply increase this value.  Note that this ONLY works
# in standalone mode, in inetd mode you should use an inetd server
# that allows you to limit maximum number of processes per service
# (such as xinetd)
MaxInstances                    30
 
# Set the user and group that the server normally runs at.
User                            proftpd
Group                           nogroup
 
# Umask 022 is a good standard umask to prevent new files and dirs
# (second parm) from being group and world writable.
Umask                           022  022
# Normally, we want files to be overwriteable.
AllowOverwrite                  on
 
# Uncomment this if you are using NIS or LDAP to retrieve passwords:
# PersistentPasswd              on
 
# Be warned: use of this directive impacts CPU average load!
#
# Uncomment this if you like to see progress and transfer rate with ftpwho
# in downloads. That is not needed for uploads rates.
# UseSendFile                   off
 
TransferLog /var/log/proftpd/xferlog
SystemLog   /var/log/proftpd/proftpd.log
 
Defaultroot                     ~