Firewalls and Security Groups

Firewall concepts

XenonCloud firewalls are stateful: return traffic for allowed connections is automatically permitted.

• Rules can match on protocol, port, and source CIDR.
• Policies can be applied to multiple instances at once.

Creating a firewall policy

1. Open Networking > Firewalls.
2. Click New firewall and give it a descriptive name.
3. Add rules such as:
   • Allow TCP 22 from your office IP.
   • Allow TCP 80 and 443 from 0.0.0.0/0 (for public web traffic).
4. Attach the firewall to one or more instances.

Lockdown patterns

• Use “deny by default, allow specific ports” as a baseline.
• Limit SSH access to known IP ranges or VPN endpoints.
• Use separate policies for admin access and public-facing services.