FAQ: Iptables rules on timely basis

Question: How can I restrict/allow access to certain service on timely basis with iptables? For example restrict access to SSH between 7:00 pm – 8:00 am on weekdays? Answer: You are welcome to use iptables patch-o-matic extension (pom or p-o-m) that allows you to match a packet based on its arrival or departure (for locally generated packets) timestamp. The syntax is the following: iptables RULE -m time –timestart TIME –timestop […]

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FAQ: How to retreive hardware manufacturer name, serial numbers, etc. in Linux command line

Question: How can I get information about hardware manufacturer, model name, serial number, BIOS information using Linux command line (CLI)? Answer: You are welcome to use dmidecode which helps to get information about your system’s hardware as described in your system BIOS. That information typically includes system manufacturer, model name, serial number, BIOS version, asset tag as well as a lot of other details depending on the manufacturer. Beware that […]

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FAQ: static routes after restart/reboot in Fedora/RedHat/CentOS

Static routing is the term used to refer to the manual method used to set up routing. An administrator enters routes into the router using configuration commands. This method has the advantage of being predictable, and simple to set up. It is easy to manage in small networks but does not scale well. Question: How can I save static routes I set up in my Fedora/RedHat/CentOS Linux after I reboot […]

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Why and how to migrate to ext4

Ext4 is the latest in a long line of Linux file systems, and it’s likely to be as important and popular as its predecessors. As a Linux system administrator, you should be aware of the advantages, disadvantages, and basic steps for migrating to ext4. IBM DeveloperWorks article explains when to adopt ext4, how to adapt traditional file system maintenance tool usage to ext4, and how to get the most out […]

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Real 10$ Wi-Fi antenna (Video)

Why spend $100 or more on a Wi-Fi antenna when you can create your own one for $10? The following components are needed: 35-mm foam (like the kind desktop and laptop PCs usually come with) Solid-core copper wire Small brass plate Multiple BNC connectors Follow the instructions in the video:

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