How to monitor large mailbox users

Monitoring mailbox users can be done in many serveral ways via web interface or via terminal or via bash scripts. With the usual mbox type emails, incoming new email messages are automatically redirected to each users’ own spool file. This spool mail is by default located and stored in /var/spool/mail. From there, the spool file(…)

How to enable and disable of telnet service

The telnet command is used to communicate with another host using the TELNET protocol. If telnet is invoked without the host argument, it enters command mode, indicated by its prompt ( telnet>). In this mode, it accepts and executes the commands listed below. If it is invoked with arguments, it performs an open command with(…)

How to block yahoo chat messenger

A very old tip and trick on blocking yahoo chat messenger from connecting to internet, as per request. Considering an approved management policies, there are several ways to block yahoo chat messenger from connecting to internet coming from inside your network, depending on what equipment and boxes you have on ground. If you happen to(…)

How to take Linux backups powered by Tar

This document entry however covers a foundation approach and mostly used tar arguments on backing up data using the linux command tar. ============================================= Data backup samples using Tar Linux command ============================================= A very simple usage of tar # tar cvf backup.tar * Legend: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -c create a new tar file -v verbose mode -f select(…)

How to take Linux backups powered by Rsync

RSync backups data and does it very clean and well. Rsync only transfers those data that have been modified and changed so that the destination host has an exact replica from the source host. Rysnc is a command line backup tool that handles data transfers in an effective and secure manner like any other known(…)

How to do MAC address packet filtering using IPTables

Media Access Control address (MAC address) or Ethernet Hardware Address (EHA) or hardware address or adapter address is a quasi-unique identifier attached to most network adapters (NICs). It is a number that acts like a name for a particular network adapter, so, for example, the network cards (or built-in network adapters) in two different computers(…)

How to Install and Configure a Caching DNS server

BIND DNS are nameservers responsible basically for resolving domain names or hostnames into their equivalent IP addresses. Websites or domain names have their own equivalent IP addresses that are usually managed and provided by the same website firms. If somebody is browsing a website from his browser, this website is being resolved, looked up and(…)

How to Install and use HTOP in Linux

This is HTOP, an interactive process viewer for Linux. It is a text-mode application (for console or X terminals) and requires ncurses. Tested with Linux 2.4 and 2.6. HTOP process viewer is not designed to replace the current well used linux ‘top’ command, but htop is an alternative with newly added and enhanced features that(…)

How to Install and Use RDesktop in Linux

We can never remove the fact that some companies still use any other desktop operating systems from their network. Several reasons for these are due to commercial and propriety softwares and customized applications that currently being managed and needed by certain specific company departments, whether those clients are located remotely or just a single department(…)

How to use Nmap for Port Scanning in Linux

How to know which port is open from unmanaged remote host? How to determine running application and services from remote host? How to do basic port scanning against a host? How to confirm ports opened from remote host? Here are a several ways to do port scanning and know which port/services are currently opened from(…)

Nagios Monitoring – How to install and generic setup

A lot of powerful monitoring tools are freely available from linux world. One of them is Nagios. Nagios is a fairly complex linux monitoring tool that determines current status of target host or equipment. Two good things about Nagios is that Nagios supports web-enabled administration page and user view-only mode account. The other one is(…)

Blue screen troubleshooting tips – Windows

Normally, the blue screen of death contains a driver name, and some addresses; if you’re lucky, removing that driver will do the trick. But what if there is no driver name on the BSoD? And what if you don’t have all the skills to play with crashdumps and debuggers? In this case, Autoruns comes to(…)