ftp.txt

sudo apt-get install vsftpd (server)
sudo apt-get install lftp (client, in maunual its ftp)

ftp default folder in ubuntu: 
/srv/ftp

Create a /srv/ftp/uploads as dropbox
sudo mkdir -m 730 /srv/ftp/uploads (as root user, but any user will be able to upload as group will be changed to ftp)
chown root.ftp /srv/ftp/uploads

Make following changes to file '/etc/vsftpd.conf'
anonymous_enable=YES
anon_upload_enable=YES
write_enable=YES

After restarting service

Use following to confirm that user is part of group ftp
id user (if not use following to add to ftp)
usermod -aG ftp user

Inorder to upload or drop the file. 
1) cd dir/where/file/exists (localhost or remote)
2) enter username/password (Or inside ftp enter user 'username')
3) cd /srv/ftp/uploads (cd to dir where you need to upload)
4) put file1.txt (file1.txt was present in the directory where we started doing ftp, other files cannot be uploaded)



TFTP

sudo apt-get install tftpd tftp(tftp for tftp clinet)
(Because this doesn't need to be started all the time, so no systemd directly)
sudo apt-get install xinetd
services which can be started using xinetd are under /etc/xinetd.d directory
Other services which 'manual' uses with xinetd are:
i)	rsync (for centos/opensuse only, not for ubuntu, use update-rc.d instead)
ii)	telnet (for ubuntu only )

All default files inside /etc/xinetd.d/ are missing following arguments which we need.
        server          = /usr/sbin/in.tftpd
        server_args     = /tftpboot
No need for following if copied like cp /etc/xinetd.d/time /etc/xinetd.d/tftp
        type            = INTERNAL
        id              = time-dgram
Complete /etc/xinetd.d/tftp
service tftp
{
        disable         = no
        socket_type     = dgram
        protocol        = udp
        user            = root
        wait            = yes
        server          = /usr/sbin/in.tftpd
        server_args     = /tftpboot
}
//
If you don't give port, it will take default port for tftp which is 69(protocol is udp)
Create the directory with right chmod and chown mentioned at server_args
sudo mkdir /tftpboot
sudo chmod -R 777 /tftpboot
Restart xinetd, you'll see at the bottom: Started working: 1 available service
Another way to confirm that tftp is running, use following 
ss -tuna(or netstat -tulpen) | grep 69

Now remote client will be able to download/get what is in /tftpboot using following
tfpt client1
get file1.txt

######################################################
# Blocking Connection using TCP Wrappers
######################################################
Add following to /etc/vsftpd.conf
tcp_wrappers=yes
Restart vsftpd
Add following to /etc/hosts.deny
vsftpd: ALL
telnet localhost ftp