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50 quick linux command tips part 2

As root 1. How to have a stop watch scenario from command line terminal? # time cat Press Ctrl+C 2. How to measure the time of executing any executable command? # time firefox wait 5 seconds and close the application 3. How to CD to a user’s home directory? # cd ~userhome 4. How to [...]

50 quick linux command tips

1. How to you change file ownership and chown files recursively? # chown user:user folder -R 2. How to view queued mail in sendmail or postfix? # mailq 3. How to show which alternative binary program does your machine executes first? # alternatives –display program-name 4. How to create public/private rsa key pair? # ssh-keygen [...]

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 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 [...]

10 Tips for Wireless Home Network Security

1. Change Default Administrator Passwords (and Usernames) At the core of most Wi-Fi home networks is an access point or router. To set up these pieces of equipment, manufacturers provide Web pages that allow owners to enter their network address and account information. These Web tools are protected with a login screen (username and password) [...]

Tips to Avoid Spyware and Virus’s

Pay Attention and Read The biggest problem is that most people do not bother to read the fine print, which is where a lot of companies can get you. Taking the extra 30 seconds to read the fine print can save you hours and hundreds of dollars (which would be spent fixing the computer). First [...]

Rsyslog – Most Advanced Log Server

Rsyslog is an enhanced syslogd supporting, among others, MySQL, PostgreSQL, failover log destinations, syslog/tcp, fine grain output format control, high precision timestamps, queued operations and the ability to filter on any message part. It is quite compatible to stock sysklogd and can be used as a drop-in replacement. Its advanced features make it suitable for [...]

How to setup Transparent Proxy with Squid

One of the many tasks we could be facing from time to time in our work is setting up and building a production proxy server. Proxy implementation could be done in several ways to achieve the same goal. One best bet we could have with this kind of setup is by using Squid linux software [...]

How to set Sendmail MTA

Long before the decades of email servers begun, a postman’s job is highly critical on delivering postal mails, not to consider those old transportation means to travel those postal mails and deliveries across the country and states. Technology is continuously evolving. Gone were the days on spending almost the whole day configuring a linux server [...]

How to Smart Host Sendmail

Sendmail can be configured to send emails directly to destination host or email server. However, network traffic congestion, email destination location, and connectivity rate sometimes affect and tend to fail a successful email delivery. Medium and large type of private networks are traditionally behind a firewall. This type of network usually sends emails directly to [...]