Ramki Technical Blog

In this post we will see how ssh works?, what is SSH tunneling? what is important of ssh tunnels and how to setup the ssh tunnel. When SSH server is installed in machine then by default its allowed ssh tunneling. SSH Tunneling (Port Forwarding) Tunneling is the concept to encapsulate the network protocol to another protocol. here we put into SSH. so all network communication are encrypted. It also called Port Forwarding. because in ssh tunneling we are going to bind one local port. so what are the packet we are going to send that particular port, all packets are transparently encrypt and delivered to remote system. What is the need for SSH Tunneling?      SSH is enough to administrate the remote system. its not enough to access the all services which are available in remote system. let i describe in the following scenario, now lets consider the scenario, System (192.168.56.101) is my system its conne...

Recently I compiled the latest kernel by manually for just fun. so i logged my experience here. I show the step by step to the compilation process. I followed the this reference for compile the kernel. Why Need to compile the Kernel? Some time some software or modules expected that some kernel flags needed to set while compile (build) the kernel. This kind of scenario we need to rebuild the kernel with specified configuration flags are set. When new kernel is released,  compile the new kernel and install in our system. But this is not recommend way to install the system. so use our distribution(Ubuntu, red-hat release )  kernel update. Check your Linux kernel version         In Linux system use uname -r or cat /proc/version to find the current kernel version Linux Kernel Version here 2.6.35.22  is current system kernel version Step 1 : Download the latest ke...

In my last post ( Virtual Host in Tomcat ) we discussed about how setup the virtual host in Tomcat. Its cost effective technique because only one public IP is enough to host multiple domain. If we have big organization and each department want to host their website in locally in different machine. then how to achieve the virtual host concept?. In this post we will see the how we do this. Update :   I posted  Virtual Host + Nginx + Tomcat  Its easy to configure, compare to Apache httpd server Problem Scenario:         In big organization they have multiple department, each department want to host their website in different machine. so these websites are accessed locally with different local IP address. When we mapping to public address then we face the problem. We have two choice either purchase as many public address or Put one server front  and delegate these request. ...

Hi in this post we will see how to setup virtual host in Apache Tomcat server. Virtual Host is in-built feature that allows to deploy multiple website(domains) in single instance of tomcat server. The main benefit in this way is its cost effective. Scenario: I am going to deploy 3 website with following domain names in single tomcat http://www.ramki.com http://www.krishnan.com http://www.blog.ramki.com The following diagram is my outline. Outline structure of Virtual Host Concept in Tomcat Here my tomcat IP address 192.168.1.15. or any IP address allocated my ISP. but it should be public IP address. How all domain names are pointing to my Tomcat?                   When we purchase the domain name we need to update the our tomcat IP address to it. like or we can simulate same DNS Setup through hosts file in both Linux and Windows. In Linux tha file is located at /etc/hosts Now How Setup...

In this post we will discuss the GRUB2 (GRand Unified Boot-loader) in Linux. recently i surfing the Linux base concepts then i came to know about grub2. here i ll share what is boot loader?, how grub2 boot loader is works? and how we can customize? and how we apply the themes? What is the Boot Loader             Boot loader is small code reside in MBR to load the kernel(core) of the operating system and give the control to OS. When PC is switched on the system controls goes to BIOS. Bios initialize the peripherals and check the booting order of the device then select the highest priority of the device execute the code stored in MBR of that device. Each Operating System shipped with boot loader For Example :- Microsoft Windows up to Windows XP comes with   NTLDR boot loader From Windows Vista onward they use BOOTMGR as a boot loader. These boot...