Some interview topics

If you are preparing for interviews for linux admin jobs you should be familiar with below concepts.. 1) Port number of different servers {cat /etc/services} 2) Linux Installation(through FTP,HTTP,NFS) 3) Boot process 4) Diff b/w ext3 and ext2 5) RAID LEVELS and Selection of raid 6) backup methods 7) Package management such as Yum server(…)

SAMBA Server Configuration

SAMBA(SMB server) is a file sharing server. Which is used to share files between Windows, Linux and Unix Systems. SMB(Server Message Block) is a proprietary protocol which is developed by MicrosoftLets see how we can configure SAMBA in Linux.Step1 : Create a directory where you want to keep data and share with other remote systems(either(…)

How To Find the process running For A Service Or Server Or User?

This is a long time question in my mind. I used to try all sorts of commands to find what process are running by a service/user. The commands are as follows. 1.#ps -ef 2.#top But none of these tools gives number of process run for an Application/User. To serve this purpose there is a built-in(…)

DIG command explained with examples in Linux

In this post I am going to teach How to use DIG and with examples. DIG is one of the most important tool in debugging DNS server related issues. Some points to be noted about DIG. 1.DIG full-form/abbreviation is Domain Information Groper 2.DIG can work on command line or as well in batch mode 3.DIG supports(…)

11 Basic Linux NMAP command Examples for System administrators

Learn nmap with examples NMAP(Network Mapping) is one of the important network monitoring tool. Which checks for what ports are opened on a machine. Some important to note about NMAP NMAP abbreviation is network mapper NMAP is used to scan ports on a machine, either local or remote machine (just you require IP/hostname to scan).(…)

How To Use IPtables to Block ICMP (Internet Control Message Protocol) Requests?

How to use IPtables to block ICMP (Internet Control Message Protocol) requests? Ans : To do this we have understand why we require this thing should be done. When Hackers try to hack in to any machine first thing they will do is a basic ping test. Code :#ping target-machine If this is succeed they(…)

SNORT(IDS/IPS) Configuration and Implemenation

Lets start how to install SNORT which is An Intrusion detection system (IDS) and an Intrusion Prevention System (IPS). We tested installation of SNORT on RHEL5. Step1 : Download following packageslibpcap-1.0.0.tar.gzpcre-8.00.tar.gzlibnet-1.0.2a.tar.gz (This is optional package if you want SMB popup alerts on window’s machines.)snort- Note : Don’t try to install SNORT through rpm packages, try(…)

How To Uninstall A Source Package?

In Linux we can install packages in so many ways such as: #rpm –ivh packagename.ver.arch.rpm This is to install from rpm package manager #yum install packagenameThis is installing through yum which will use rpm package manager internally #apt-get install packagenameThis is for installing .deb packages #sh file.shThis is from a shell script. #./configure;make;make check;make installThis(…)

How To Log DNS Server Activity?

How to log DNS server activity? Ans : Sometimes you require to log DNS server activity to a file for future reference for analyse the activity on DNS server and whether DNS server is properly resolving accurately or not. rndc(remote name daemon control) is the command to use for DNS server activity logging. Let’s have(…)

How To Take The Backup Of MBR(Master Boot Recorder)

1.How to take the backup and restore MBR? Why do you require to take the backup of your MBR? Ans : MBR (Master Boot Recorder) is a vital part of your hard disk which contains booting information, without it its difficult to boot the system. Suppose you have windows and Linux duel boot on your(…)