Firewall & networking

Open ports, set up UFW and configure IPv4/IPv6.

schedule5 min reading timeupdateLast updated: 10/21/2026

UFW (Uncomplicated Firewall)

UFW is the recommended firewall for Ubuntu/Debian. It is inactive by default after installation.

bash

# Install & enable UFW
apt install ufw
ufw default deny incoming
ufw default allow outgoing
ufw allow ssh          # Port 22
ufw allow 80/tcp       # HTTP
ufw allow 443/tcp      # HTTPS
ufw enable

Opening individual ports

bash

ufw allow 25565/tcp    # Minecraft
ufw allow 30120/tcp    # FiveM
ufw allow 8080/tcp     # Custom port
ufw status verbose     # Show current rules

Using your IPv6 address

Every KVM server automatically receives an IPv6 address. To connect via IPv6:

bash

ssh root@[2a01:4f8:xxxx:xxxx::1]

lightbulb

UFW filters IPv4 and IPv6 alike (IPV6=yes in /etc/default/ufw is the default on Ubuntu). Only open the ports you really need. No server firewall protects against large DDoS attacks – that is the job of the data center's DDoS protection, which is included with every KVM server. Offering a service over IPv6 only adds no extra protection here.

Was this article helpful? Need clarification?

support_agentOpen ticket