Linux Archives

Over 80% is running on some form of Linux – so does your Mac and you iPhone. Sometimes we have to get our hands dirty on the command line – it makes you feel like a proper hacker.

Here are some pointers I picked up on my journey.

How to disable SSH access from everywhere except for certain IPs in CentOS 7

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Here’s how to do it: firewall-cmd –zone=internal –add-service=ssh –permanent firewall-cmd –zone=internal –add-source=1.2.3.4/32 –permanent firewall-cmd –zone=internal –add-source=5.6.7.8/32 –permanent firewall-cmd –zone=public –remove-service=ssh –permanent firewall-cmd –reload This declares an internal zone with two IPs (add as many or as few as you like) and subsequently removes the SSH service from the public zone altogether. As a result, any … Read more

How to install Parallels Tools via the Command Line in CentOS

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I like setting up barebones CentOS and other flavoured VMs on my Mac via Parallels Desktop. Trouble is, for such things like time synchronisation to work properly, something called Parallels Tools needs to be installed on each VM. This is to make sure Parallels Desktop can speak to the VM and communicate with it properly. … Read more

How to update Plesk via the Command Line

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You can update Plesk via the Web Interface (under Tools and Settings – Updates and Upgrades). However sometimes the interface times out, or browsers get confused – therefore it’s good to know that you can apply updates via the command line interface as well. In this article I’ll show you how (in Linux – I … Read more

How to open SMTP port 587 to send emails in Plesk

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By default Plesk on Linux uses Postfix for outgoing email, and by default listens on port 25 for outgoing SMTP mail. Some service providers do not allow to send emails on that port, and tragedy occurs: clients can’t send email with their Plesk servers. Not good. Other SMTP ports will usually work, such as the … Read more

How to turn off all Plesk Health Monitor alert emails

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I have previously described how to adjust the values that the Plesk Health Monitor uses to determine when an email should be sent out. There is also a way to switch these emails off entirely. Here’s how: To turn off the daemon that is responsible for sending these emails, issue this: /etc/init.d/psa-health-monitor-notificationd stop No more … Read more