OSI model and PDUs

Two concepts from my Network+ study: the OSI model and PDU. OSI stands for Open Systems Interconnect and is used as a conceptual model to ease data transmission and communication. Read more about it here and here. PDU stands for Protocol Data Unit and describes the unit that is being used on a particular layer…

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CentOS 7 FTP server setup

I needed FTP access to my VPS since there was a WordPress update and I didn’t feel like it to do it manually: FTP / SFTP / SCP to your server and do the update from there. Fortunately installing and configuring it is easy. After configuration you can immediately login with an admin user that…

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CentOS 7 – Zimbra 8.7.4_GA change ssh portnumber

So, with the fresh certificate in the pocket, we’ll be going for new adventures. The first one being Zimbra, my initial choice for a collaboration suite. Email, calendar, contacts and tasks will be my main purpose for this suite. I’m installing the suite (yesterday and today…) and am stumbling upon A LOT of problems. Problems…

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