Networking & Security
Networking fundamentals, DNS, SSL, firewalls, and server protection — from the basics to advanced security setups.
WordPress hosting security · Guidance checked October 30, 2026 Your WordPress dashboard says everything is up to date. That does not tell you whether the
Linux kernel security · Advisory status checked October 30, 2026 A Linux server can have updated packages and still be running a vulnerable kernel.
A public certificate and a secret private key do different jobs. Follow the checks behind HTTPS identity and test a trust decision in a temporary workspace.
October 29, 2026 · Linux server security · Based on the October 28 release If Tailscale is how you reach your Linux servers, check which version is running
One wrong firewall rule or SSH setting can lock you out of your own Linux server. Follow a safer hardening sequence: verify recovery access, test SSH keys
Your Linux server's SSH logs show unfamiliar IP addresses, invalid usernames, and failed passwords. Is someone breaking in? Learn what these messages actually
A new Linux server may seem empty and quiet. But once it has a public IP address, internet scanners can begin discovering its exposed services.
A Linux server can reach an IP address and still fail when an application uses a hostname such as example.com. Before the connection can begin, something
An IP address can get a packet to the right server, but a server may be running SSH, a web server, a database, DNS, and many other networked programs at the same time.
Networking foundation TCP and UDP both carry application data across IP networks, but they make a different promise. TCP protects an ordered conversation.