Kerberos Authentication is a means by which a communicating entity on a non-secure network can prove itself to another entity about its identity in a secured way. In a system developed for a client-server model, it is inconceivable to identify the threat posed by the network users and the intruders. Primary goal of Kerberos Authentication System is to prevent free text based transmission of passwords over the network. Kerberos was created by MIT with a license similar to BSD and the current version is Version 5. It is implemented across various OS - Linux, Unix, Windows, MacOS. Kerberos system is built on a symmetric key algorithm. (more…)

There are times when you would like to do some changes in your web server configuration file which might necessitate the server to be restarted in order for the changes to take effect. Issuing a apache restart command will forcefully close all the connections made to the web server which will end any user related activity on the server. If you would want to avoid such scenarios then issue the following command $ sudo /etc/init.d/apache2 graceful (in ubuntu)

Linux: History command Each bash sessions stores the history of commands executed in .bash_history file which in turn in stored under each user's home directory usr100@dev01:/tmp/user$ ls 07-14.txt a.txt b.txt d.txt usr100@dev01:/tmp/user$ cat ~/.bash_history clear su root rm -i d.txt ls -ltr touch c.txt

Troubleshooting the above warning message in Nagios: i) If you can specify the IP address of the host with its port number try specifying it that way instead of the host name ii) Check the the time that is set for the http check parameter and based on it try setting the -w (warning message) parameter (sample setting: command_line /usr/lib/nagios/plugins/check_http -H mywebsite.com -t 60 -w 55)

The following command will give you the environment settings in Linux $ env This is equivalent of PATH in windows.

Setting Tomcat to work on port 80 instead of port 8080 There may be instances when you want Tomcat to run on port 80 and not on port 8080 which is the default port allocated to it on installation. If Apache is installed in the machine, then you need to stop the apache server (if this were to be for a temporary cause) and if you need it permanently then you should disable apache on start up. (more…)