TFTP Server is useful for PXE booting or upgrade of routers/switches etc. A simple but working tftp server is available in Ubuntu is tftpd-hpa.

Install package:

sudo apt-get install tftpd-hpa

Edit server configuration:

sudo vim /etc/default/tftpd-hpa

and set your tftp root directory:

TFTP_DIRECTORY="/home/tftpd"

Manage service:

sudo service tftpd-hpa [status|stop|start|restart|force-reload]