How to switch from NetworkManager to systemd-networkd on Linux

In the world of Linux, adoption of systemd has been a subject of heated controversy, and the debate between its proponents and critics is still going on. As of today, most major Linux distributions have adopted systemd as a default init system. Billed as a “never finished, never complete, but tracking progress of technology” by […]
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How to configure virtual hosts in Apache HTTP server

Virtual hosting refers to the technique that allows a physical server to host more than one website domain (e.g., site1.com, site2.com). Virtual hosting is prevalent in shared web hosting environments, where typically hundreds or more of websites or blogs are packed on a single dedicated server to amortize server maintenance cost. You are not a […]
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How to combine two graphs on Cacti

Cacti is a fantastic open source network monitoring system that is widely used to graph network elements like bandwidth, storage, processor and memory utilization. Using its web based interface, you can create and organize graphs easily. However, some advanced features like merging graphs, creating aggregate graphs using multiple sources, migration of Cacti to another server […]
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How to access a Linux server behind NAT via reverse SSH tunnel

You are running a Linux server at home, which is behind a NAT router or restrictive firewall. Now you want to SSH to the home server while you are away from home. How would you set that up? SSH port forwarding will certainly be an option. However, port forwarding can become tricky if you are […]
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What is a good alternative to wget or curl on Linux

If you often need to access a web server non-interactively in a terminal environment (e.g., download a file from the web, or test REST-ful web service APIs), chances are that wget or curl is your go-to tool. With extensive command-line options, both of these tools can handle a variety of non-interactive web access use cases […]
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How to secure BGP sessions using authentication on Quagga

The BGP protocol runs over TCP, and as such, it inherits all the vulnerabilities of a TCP connection. For example, within a BGP session, an attacker may impersonate a legitimate BGP neighbor, and convince the BGP routers on the other end to share their routing information with the attacker. The problem occurs when the attacker […]
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How to set up remote desktop on Linux VPS using x2go

As everything is moved to the cloud, virtualized remote desktop becomes increasingly popular in the industry as a way to enhance employee’s productivity. Especially for those who need to roam constantly across multiple locations and devices, remote desktop allows them to stay connected seamlessly while preserving their work environment. Remote desktop is attractive for employers […]
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How to secure SSH login with one-time passwords on Linux

As someone says, security is a not a product, but a process. While SSH protocol itself is cryptographically secure by design, someone can wreak havoc on your SSH service if it is not administered properly, be it weak passwords, compromised keys or outdated SSH client. As far as SSH authentication is concerned, public key authentication […]
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How to set up server monitoring system with Monit

Many Linux admins rely on a centralized remote monitoring system (e.g., Nagios or Cacti) to check the health of their network infrastructure. While centralized monitoring makes an admin’s life easy when dealing with many hosts and devices, a dedicated monitoring box obviously becomes a single point of failure; if the monitoring box goes down or […]
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