Cisco ASA stands for Cisco Adaptive Security Appliance. Cisco ASA acts as both firewall and VPN device. This article explains how to setup and configure high availability (failover) between two Cisco ASA devices. On a production environment, it is highly recommended to implement two Cisco ASA firewall (or VPN) in high available mode. This way, [...]
September 2011
Parted is a GNU utility, which is used to manipulate the hard disk partitions. Using parted, you can add, delete, and edit partitions and the file systems located on those partitions. You can also clone partitions. This article explains 9 practical parted command examples. Warning: Parted utility manipulates the hard disk partition table and saves [...]
Bash is the default shell on Linux. If you are spending lot of time on Linux environment, you should master the Bash command line features to become efficient. Apart from being an interactive shell, Bash is also a scripting language, which allows you to automate your tasks using Bash shell scripting. Bash 101 Hacks is [...]
If you are a Linux sysadmin, you might not want others in your IT department, who has physical access to the server, change anything from the GRUB bootloader menu that is displayed during system startup. GRUB is the 3rd stage in the Linux boot process that we discussed earlier. GRUB security features allows you to [...]
If you are running tomcat server that runs only on HTTP, follow the 2 easy steps mentioned below, to configure tomcat for SSL. 1. Create Keystore using Java keytool First use the keytool to create a java keystore as shown below. Make sure to note down the password that you enter while creating the keystore. [...]
Perl developers should understand how to use complex data structures effectively. In this article, I picked the top 5 useful posts about complex data structures from perlmonks, and gave simple examples on how to use them. 1. Perl Array of Arrays The following example defines a sample perl array of arrays. @tgs = ( ['article [...]
htop is just like top, but on steroids. Once you are used to htop, you’ll never go back to top again. htop is a ncurses-based process viewer. You can interact with the htop using mouse. You can scroll vertically to view the full process list, and scroll horizontally to view the full command line of [...]