Sunday, 16 August 2009

How to make an effective power point presentation?

Are you Planning to make an Effective Power Point Presentation (PPT) for your lecture / workshop / Conference.... Then i hope these tips may be of use to you. 






Thursday, 13 August 2009

Setting up TFTP server on Ubuntu 9.04 (Jaunty)


Tftp is a server/client implementation which supports the Internet Trivial File Transfer Protocol. TFTP is a file transfer protocol, with the functionality of a very basic form of File Transfer Protocol (FTP).

Advantages of the protocol
  • simple design
  • implemented in a very small amount of memory
Usage
  • Booting devices such as routers which did not have any data storage devices
  • transfer small amounts of data between hosts on a network
  • initial stages of some network based installation systems to load a basic kernel that performs the actual installation.
TFTP Details
  • It uses UDP port 69 as its transport protocol (unlike FTP which uses TCP port 21)
  • It cannot list directory contents.
  • It has no authentication or encryption mechanisms.
  • It is used to read files from, or write files to, a remote server.
  • Supports three different transfer modes, "netascii", "octet" and "mail" (Obsolete)
  • Generally used on private, local networks - Due to lack of security

For further details on the protocol refer: http://en.wikipedia.org/wiki/Trivial_File_Transfer_Protocol

For setting up TFTP server on Ubuntu you can use either tftpd, atftpd or tftpd-hpa.

tftpd Setup

Install tftpd on your system.

#sudo apt-get install tftpd

Configuring the tftpd directory:

#sudo mkdir /tftpboot ; if directory is not yet created
#sudo chmod -R 777 /tftpboot
#sudo chown -R username:username /tftpboot ;replace 'username' with your actual username


Create /etc/xinetd.d/tftp and insert the following:
service tftp
{
socket_type = dgram
protocol = udp
wait = yes
user = username ; Enter your user name
server = /usr/sbin/in.tftpd
server_args = -s /tftpboot
per_source = 11
cps = 100 2
disable = no
}


Now restart the tftpd server

#sudo /etc/init.d/xinetd start



advanced TFTP server (atftpd) setup

atftp is a client/server implementation of the TFTP protocol that implements RFCs 1350, 2090, 2347, 2348, and 2349. The server is multi-threaded. & also supports multicast protocol known as mtftp, defined in the PXE specification.

Install the server using the command:

#sudo apt-get install atftpd

Configuring the directory:

#sudo mkdir /tftpboot ; if directory is not yet created
#sudo chmod -R 777 /tftpboot
#sudo chown -R username:username /tftpboot ;replace 'username' with your actual username
#sudo /etc/init.d/atftpd restart

If you want ATFTP to be run as a server directly than through inetd, try the following

#sudo vim /etc/default/atftpd

Change the 'USE_INETD=true' line to 'USE_INETD=false'.... save and quit.

Use the following command to start atftpd:

#sudo invoke-rc.d atftpd start



tftpd-hpa setup

This is a tftp server derived from OpenBSD tftp with some extra options added. Like atftpd It is useful if you want to use the PXE protocol which has some non-standard requirements for tftp.

Install tftpd on your system.

#sudo apt-get install tftpd-hpa

While installation it will ask whether you need to configure the server or not. Enter yes to do a default configuration. By default the system will consider "/var/lib/tftpboot" as the default directory.

If you need to change the default directory to '/tftpboot', then create a directory as mentioned earlier, give the necessary permissions and then edit
'/etc/default/tftp-hpa'.


Modify 'OPTIONS="-l -s /var/lib/tftpboot" to
'OPTIONS="-l -s /tftpboot"

and restart the server

# sudo /etc/init.d/tftpd-hpa restart



To run the tftpd-hpa as a daemon, set in '/etc/default/tftp-hpa' the following:

RUN_DAEMON="yes"

and restart the server

# sudo /etc/init.d/tftpd-hpa restart