December 23, 2013

Why You Should Implement equals() and hashCode() In Hibernate

It is not directly obvious why you should override and implement equals() and hashCode() in Hibernate. Here are two good documentation for why:

- Hibernate ORM documentation

JBoss Community Wiki

Essential iptables on RHEL

I good getting starting guide and also very well explained is casting by Red Hat.'

Hardening access to network services with iptables

Hardening Apache Web Server (httpd)

For hardening Apache Web Server, look at

Hardening RHEL 6

For Red Hat Enterprise Linux 6 hardening, look at

Packt’s $5 eBook Bonanza is back!

Following on from the success of last year’s festive offer, the publisher will be celebrating the holiday season with an even bigger $5 Bonanza.

From December 19th, customers will be able to get any eBook or Video from Packt for just $5. This sale covers every title in the 1700+ range and customers can grab as many as they like until January 3rd 2014 – more information is available at

December 21, 2013

Hardening RHEL5

The NSA has been getting a lot of attention in the media lately, but NSA has also published a lot of interesting document. A good example of that is the

Guide to the Secure Configuration of Red Hat Enterprise Linux 5

December 11, 2013

JBoss Vault in JBoss EAP 6.2.0 uses jceks as Default KeyStore Type

Today I upgraded to JBoss EAP 6.2.0, but ran into some trouble with the keystore I have. I have one for the SSL connector and one for the JBoss Vault.

To be able keep you old JBoss Vault keystore that is stored with the jks format you need to add the KEYSTORE_TYPE vault option.


December 10, 2013

Changing Broadcom Driver In Ubuntu

I have a Broadcom Wireless Network Adapter and I had all sort of problem with the standard driver, Broadcom STA Wireless driver or wl that the module is called.

To identify which Broadcom chipset you have. Run:

To identify which modules (driver) you are using (running):

I had the STA or wl module running. To remove all possible Broadcom modules.

And to really remove the default STA or wl module, also remove the debian package. After the purge, that remove configuration files as well, I double run apt-get with remove autoremove, which will remove unused package and finally I run clean, to clean the apt-get cache. All for precaution.

Now you must test which driver/module that suites you best. I started with the b43 driver/module.

To load the new module/driver.

Now test you installation, if successful reboot and double check, that everything is working correctly..

Other possible driver are b43legacy package firmware-b43legacy-installer and LP-PHY package firmware-b43-lpphy-installer.

For more hardware commands, please read


December 7, 2013

The Medibuntu Project has come to an end

For many people the first thing they have done after installing Ubuntu, was to add the Medibuntu repository. But now it is dead. See announcement Here.

But what is the impact? Not much. Ubuntu already offers most of the things that existed in Medibuntu and this only natural progress of the growth of Ubuntu.

December 5, 2013

Managing Network in RHEL 6


The simplest way to manage network settings is to use the system-config-network tool or the non-graphical variant system-config-network-tui

To start, stop, status all our network devices

Other useful tools are:

ifconfigDisplay our network settings.
pingUsed for check network connectivity
route -nDisplay routing and Gateway
tracerouteDisplay network routing to a host.
netstat -nrDisplay open ports.


Main network configuration file is /etc/sysconfig/network-scripts/ifcfg-<name>.



Local routing for e.g. localhost, but also for static routing.

Main routing configuration file. Any changes will be overwritten, unless disabled in above sysconfig network-scripts with PEERDNS=no.


  • network-scripts: /usr/share/doc/initscripts-<version>/sysconfig.txt