Find reliable, clear information on server hardening for Ubuntu 18.04 Linode

I love to learn but one of the most challenging aspects for me is determining what the best (up to date, widely agreed upon, and attested to by professionals) information is. Also, there isn't much pressure when learning about something just for fun, but if it's something you are investing your future into (like a business venture) it becomes a whole other story..

For me right now the topic is server hardening. I have almost no experience with networking, firewall rules, iptables, ufw, or any of it. Now, I can learn the tools easy enuf but formulating the right strategy / security policy is not something I think I can find out without a little assistance.

I would really, really appreciate if some more experienced folks would chime in; and, possibly, offer resources / sources on the modern, 2019, widely accepted, industry best practices for server hardening. Yes I need / want to understand some theory but really what I need most is flat out instruction I can rely on and get this accomplished.

Thank you so much for any assitance. I really would appreciate anything that could save me a little time and left me confident it got done right.


2 Replies

The term "Server Hardening" is a very broad term that you're not going to find flat out instruction for that you can rely on to cover all your needs. Pleasure and business are two different scenarios that will determine how you go about dealing with server security.

For example, if you're running something for yourself or for testing purposes, then you have the luxury of making mistakes and trying things out. If something breaks, no worries. However, if you're looking to go into the business aspect of running some server for someone, then you have far more things to consider since you're in charge of someone else's data and handling issues when they arise.

You're going to need to know enough about how the system you're running for your business or client works and what common types of threats target such system. For example, a mail server is going to have a certain loose set of issues like spammers trying to turn it into junk mail relay that you're going to have to deal with (or not).

Now, in regard to setting up firewall rules, iptables and ufw are essentially the same thing. The difference is that UFW is a simpler way to create rules for iptables, rather than manually write them out; You're still using iptables though.

Server hardening doesn't really mean much, because anything connected to the internet is always vulnerable to some type of attack and where there's a strong enough will, there's a way…

At the most basic level, security, is doing things like, for example, using strong passwords and storing these passwords in something secure like an encrypted database, Joining a security mailing list for the OS you use so you know when and what patches are available, actually applying those security patches, and helping to seal off common points of entry both physically and software wise.

In the end, the things I mentioned aren't things that you just do quickly and be done with it. Server security is an ongoing process that requires your regular attention, commit, and knowing what's going on with your system.

Most importantly, no matter how good you are, if SHTF, you're going to want to have reliable backups and you can restore from.

Much appreciated advice. Thank you.


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