How to list out opened host ports in Linux

Opened host ports are usually the most non-physical direct way of forcing entry remotely. Here you would see several tools and ways how to list out your currently opened ports from your managed linux box. Let’s view our first attempt to list out those opened and used ports. # netstat -panut | grep LISTEN We(…)

How To Add Sites to the Trusted Zone in IE7

Internet Explorer 7 provides four different zones for which you can establish different security settings. Using separate settings for your trusted sites and the rest of the Internet can allow you to view all the content on trusted sites, while limiting the vulnerabilities other sites could potentially exploit. Follow these instructions to add sites to(…)

How to Sync date and time via NTP server

Syncronizing your current date and time is as important as making database backups. Without proper accurate stamped date and time, any backup file with any stamped date on it would be meaningless. Without correct time and date, those scripts that depend on date and time schedule would be executed inaccurately and would give you result(…)

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 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 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(…)

How to setup and install TFTP server

The Trivial File Transfer Protocol (TFTP) is normally used only for booting diskless workstations. The tftp-server package provides the server for TFTP, which allows users to transfer files to and from a remote machine. TFTP provides very little security, and should not be enabled unless it is expressly needed. The TFTP server is run from(…)

How To Scan DNS BIND Conf File For Errors On Fedora

What is BIND? BIND (Berkeley Internet Name Domain) is an implementation of the DNS (Domain Name System) protocols. BIND includes a DNS server (named), which resolves host names to IP addresses; a resolver library (routines for applications to use when interfacing with DNS); and tools for verifying that the DNS server is operating properly. When(…)

How To Selectively Archive and Backup MBox/IMAP Mails Using ArchiveMail

What is Archivemail? Archivemail is a tool written in Python for archiving and compressing old email in mailboxes. Archivemail can move specific and/or group of mbox/imap email messages older than the specified number of days to a separate mbox format mailbox that is compressed with gzip, or optionally just delete old email or simply archive(…)