Installing TFTP server atftpd in Linux

I need a TFTP server to keep configurations files. I need the server to be simple to setup and be able to send or receive any file without any restrictions. It would be for a lab environment so a strict security is not necessary. I'm using Linux Mint.
In Linux I could find three different TFTP servers: 

• tftpd
• atftpd
• tftpd-hpa

Already tried tftpd see my other post Installing TFTP server in Linux. A minor problem is that you cannot transfer a file to the TFTP server.

Installing atftpd

sudo apt-get install atftpd

Create folder
In my example I want to use  folder /tftpboot for the atftp 

sudo mkdir /tftpboot  
sudo chmod -R 777 /tftpboot  
sudo chown -R nobody /tftpboot  

Edit configuration file
Default config file /etc/default/atftpd contains this :

USE_INETD=true
OPTIONS="--tftpd-timeout 300 --retry-timeout 5 --mcast-port 1758 --mcast-addr 239.239.239.0-255 --mcast-ttl 1 --maxthread 100 --verbose=5 /srv/tftp"

Make changes to run as a server directly, not through inetd ( default)
Replace : 

USE_INETD=true

to

USE_INETD=false

Increase logging level by setting to --verbose=7 to capture all messages

Replace location of folder

/srv/atftp

to

/tftpboot

Added location for log file --logfile /var/log/atftpd.log

Final atftp config file :

 $ cat /etc/default/atftpd   
 USE_INETD=false  
 OPTIONS="--tftpd-timeout 300 --retry-timeout 5 --mcast-port 1758 --mcast-addr 239.239.239.0-255 --mcast-ttl 1 --maxthread 100 --verbose=7 /tftpboot --logfile /var/log/atftpd.log"   

Touch /var/log/atftpd.log and set permissions accordingly

sudo touch /var/log/atftpd.log
sudo chmod 644 /var/log/atftpd.log

Start the server

sudo invoke-rc.d atftpd start

Starting Advanced TFTP server: atftpd.

Verify running of TFTP server

netstat -lnp | grep ":69 "
udp        0      0 0.0.0.0:69              0.0.0.0:*  

Install Client

sudo apt-get install atftp

Testing TFTP sever
Testing the TFTP server can be done in different ways.
One method is to test it from the same machine where TFTP server was installed, thus referring to localhost. 
An  from another physical machine. 

Create a file on the Client 

touch test-file.txt

Start TFTP sever

atftp localhost

tftp> put test-file.txt

Check if file was transferred to the designated folder

ls -al /tftpboot/
-rw-r--r--  1 nobody nogroup        0 Oct  12 00:33 test-file.txt

Further testing on different file sizes
After some complains I decide to check it by transfering different file sizes.I create few dummy files of different file sizes using the dd linux command

dd if=/dev/zero of=testfile-[MBytes].test bs=[bytes] count=1   

for example I created three dummy files 30MB, 40MB, 50MB

dd if=/dev/zero of=testfile-30MB.test bs=31457280 count=1  
dd if=/dev/zero of=testfile-40MB.test bs=41943040 count=1  
dd if=/dev/zero of=testfile-50MB.test bs=52428800 count=1  

After creation they should appear like below

.. 31457280 Mar 6 21:24 testfile-30MB.test  
...41943040 Mar 6 21:24 testfile-40MB.test  
.. 52428800 Mar 6 21:24 testfile-50MB.test  

Transferring the 30MByte file , was successful but the 40MByte was not.

 $ atftp 192.168.3.21  
 tftp> put testfile-30MB.test  
 tftp> put testfile-40MB.test  
 tftp: error received from server <Disk full or allocation exceeded>  
 tftp: aborting  

Further investigation shows that max file size is 32MB

 tftp> put testfile-31MB.test  
 tftp> put testfile-32MB.test  
 tftp: error received from server <Disk full or allocation exceeded>  
 tftp: aborting  

It appears that problem is on the file size and not the protocol itself.
There are some explanations in forums and suggestions  (1) ( 2) 

Real life example
Sending the running config from my cisco switch

DLS1#copy running-config tftp://172.30.1.193
Address or name of remote host [172.30.1.193]?
Destination filename [dls1-confg]?
!!
3941 bytes copied in 1.040 secs (3789 bytes/sec)

Checking if transfered on the TFTP server

$ls -al /tftpboot/
-rw-r--r-- 1 nobody nogroup  3941 Οκτ 12 12:46 dls1-confg