A quick note on the links related where to find the ubuntu releases and how to do a checksum to ensure that the downloaded copy
If you are downloading Ubuntu from the official site, MD5/SHA1 checksum (ubuntu hashes) for latest releases may not be listed there.
If it is not there, you can visit the site http://releases.ubuntu.com/. This site lists a comprehensive list of ubuntu releases and their checksums. Checksums ensure that the download is complete without corruption and is 100% accurate. So, it is always advisable to do a checksum after each download.
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.
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
07-14.txt a.txt b.txt d.txt
usr100@dev01:/tmp/user$ cat ~/.bash_history
rm -i d.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)
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.
Configuring Tomcat in Ubuntu with Apache server running on it
Login with the root account. Check if java is already installed on the machine. If not, first install java on ubuntu.
Web get the apache-tomcat tar file from the below location