Setup default gateway with route command Linux

Display default route The following three commands display the current routing table: # route Output: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface * U 0 0 0 ra0 default dsl-router UG 0 0 0 ra0 # /sbin/route Output: Kernel IP routing table Destination Gateway Genmask Flags Metric […]

Installing iostat in CentOS with yum

Iostat is a very powerful tool for monitoring the throughput of your storage subsystems. Especially to locate bottle necks and pinpoint possible upgrade scenarios. Not immediately visible here is how to install it on Centos 5.x and 6.x. We shall use the whatprovides tool in yum to locate the packages that provide iostat  

Installing vim editor.

To install vim [root@testarossa-00-0c-29-47-8f-35 ~]# yum whatprovides vim-enhanced Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: * epel: * extras: * updates: 2:vim-enhanced-7.0.109-7.el5.i386 : A version of the VIM editor which includes : recent enhancements. Repo : base Matched from: [root@testarossa-00-0c-29-47-8f-35 ~]# yum install vim-enhanced-7.0.109-7.el5.i386 Loaded plugins: fastestmirror […]

VIM cheat sheet

< The list of Vim commands > Working with files Vim command Action :e filename Open a new file. You can use the Tab key for automatic file name completion, just like at the shell command prompt. :w filename Save changes to a file. If you don’t specify a file name, Vim saves as the file name […]

List interfaces and IPs neatly

The following command gives a neat list of the Devices and their IPs / details without all the gruesome details. ifconfig | egrep  "Link|inet" A sample result would be: [root@testarossa-00-0c-29-47-8f-35 vm]# ifconfig | egrep "Link|inet" eth0 Link encap:Ethernet HWaddr 00:0C:29:47:8F:2B inet addr: Bcast: Mask: eth1 Link encap:Ethernet HWaddr 00:0C:29:47:8F:35 inet addr: Bcast: Mask: lo Link […]

Dsabling SElinux In Centos

Sometimes and with some DB platforms especially when you are testing and want to reduce the number of variables during development, testing etc.. you don not want SELinux watching your back. While it is a must to enable SELinux in hardened production systems it can be quite a pain to handle. Sometimes it needs disabling […]

Slash notation lookup table

Total-addresses: how many unique addresses can be represented. To determine how many are available to be assigned to devices you need to subtract 2 from the provided number to allow for the ‘network’ and ‘broadcast’ address. A further one of these may need to be assigned to a router. Net bits Subnet mask Total-addresses /20 4096 /21 […]

Introduction to APT (advanced package Tools)

Advanced Packaging Tool Ubuntu — and all Debian-based distros — includes the Advanced Packaging Tool (APT), which can be used to easily download and install software for the operating system. This article looks at APT, and how it is used. Topics : Table of Contents Installing Software on a Computer Installing Software on Windows Installing Software on […]

Introduction to Yum

1. Introduction   Yum is a tool for automating package maintenance for a network of workstations running any operating system that use the Red Hat Package Management (RPM) system for distributing packaged tools and applications. It is derived from yup, an automated package updater originally developed for Yellowdog Linux, hence its name: yum is “Yellowdog Updater, Modified”. Yup was originally […]