Server hacking and unauthorized access are genuine threats. These reasons are why you should implement a firewall as part of your overall network security strategy. Configuring a firewall with iptables rules is one way to mitigate such risks on Linux...
OPNsense is an open-source, FreeBSD-based firewall and routing security software that also acts as a DNS resolver for all of your desktops and mobile devices. Learn how to configure the OPNsense DNS resolver to encrypt all DNS queries to protect from eavesdropping and increase your privacy and security online in this tutorial.
A content filtering proxy server, helps distribute Internet access while providing control to the administrators over the content delivered. It is usually used in organizations or schools to ensure that Internet usage conforms to the local acceptable use policy. A content filtering proxy must necessarily accommodate the demands of granular rules for Internet access privileges and restrictions across an enterprise.
Here's a quick step-by-step guide on setting up a proxy server. It's great to have such functionality freely available. But like all tools, how much knowledge do you think you need to make it work consistently and effectively?