4.1.3 Networking & firewalls

6 entries

• 0103 Proxmox VE networking: Linux bridges (vmbr0) and VLANs Guests reach the network through Linux bridges such as vmbr0, defined in /etc/network/interfaces. Learn the default setup, VLAN-aware bridges, VLAN tags for… Intermediate · How-to · Linux Article Installation & first steps · Networking & firewalls 15 Oct 2026
• 0167 Fix: Job for nginx.service failed because the control process exited with error code systemctl prints this when a service's start command exits with an error. The real reason is in journalctl; for nginx it is… Intermediate · Fix · Linux Article Networking & firewalls · Services & systemd 15 Oct 2026
• 0173 Set a static IP address: nmcli on RHEL vs netplan on Ubuntu RHEL, Rocky and AlmaLinux configure networking with NetworkManager (nmcli); Ubuntu Server uses netplan YAML. Here is the same static IP setup in… Intermediate · How-to · Linux Article Networking & firewalls 15 Oct 2026
• 0174 Network and DNS troubleshooting commands: ip, ss, dig, resolvectl A layer-by-layer cheat sheet for "the server cannot reach X": interfaces and routes with ip, listening ports with ss, and name resolution… Beginner · Reference · Linux Article Networking & firewalls 15 Oct 2026
• 0175 Open ports with firewalld and ufw firewalld (RHEL, Rocky, AlmaLinux) and ufw (Ubuntu) are friendly front ends to the kernel firewall. Allow SSH first, then open only the… Intermediate · How-to · Linux Article Networking & firewalls 15 Oct 2026
• 0249 Set up and harden a fresh Linux server in one afternoon Take a new Ubuntu, Debian or Rocky/Alma server from first login to a safer baseline: sudo admin, SSH keys only, firewall, automatic… Beginner · Tutorial · Linux Article Networking & firewalls · Packages & updates · Users, sudo & hardening 15 Oct 2026