---
title: OS Template List
description: "## OS Template List You can immediately deploy virtual machines from the following OS templates. Our templates are based on **server use cases (minimal configuration / no GUI)**. --- ## Important: Standard Security Specifications (Common to All Templates) Our templates…"
url: "https://bestnetllc.co.jp/en/docs/os-template-list/"
updated: "2026-06-08"
category: "BESTNET-CLOUD"
---

# OS Template List

## OS Template List

You can immediately deploy virtual machines from the following OS templates.
Our templates are based on **server use cases (minimal configuration / no GUI)**.

---

## Important: Standard Security Specifications (Common to All Templates)

Our templates maintain the following as standard specifications to ensure initial safety and consistent operations.

### 1) OS Internal Firewall (Initial Configuration)

- By default, the OS internal firewall functionality (e.g., ufw / firewalld, etc.) is **disabled**.
- Initial access control is primarily handled by **network-side firewall** (controlled by us).
- Of course, you can also **enable and operate the OS firewall on your side** as needed.

> Note: When enabling the OS internal firewall, be careful not to block your own management access such as SSH.

### 2) Network-Side Firewall (Standard Policy)

We apply standard policies on the network side to prevent unauthorized use (Abuse) and ensure stable infrastructure operations.

#### Inbound (IN / Inbound)

- **Default: Deny (DROP)**
- **Initial Permissions (Standard):**

  - SSH: TCP/22 (Inbound Allowed)
  - ICMP: Inbound Allowed (for connectivity verification and routing control)

In the initial state, inbound traffic other than SSH and ICMP is blocked.
If you need web publishing (80/443), etc., please add it via **the Network Firewall in the control panel**.

#### Outbound (OUT / Outbound)

- **Standard: Allowlist (Whitelist) Method**
- **Outbound Permissions by Default (Standard):**

  - DNS: UDP/53, TCP/53
  - NTP: UDP/123
  - HTTP: TCP/80
  - HTTPS: TCP/443
  - QUIC / HTTP3: UDP/443
  - ICMP: Outbound Allowed (for connectivity verification and routing control)

Outbound communications other than the above are generally blocked.
If you need additional outbound ports, please **submit a request via [support ticket](https://bestnetllc.co.jp/en/encyclopedia/support-ticket-en/)** (review and conditional approval may be applied depending on purpose, destination, duration, etc.).

> Note: For reasons such as anomaly detection, upstream requests, and attack mitigation, we may restrict ICMP types (Type/Code) or communication conditions.

### 3) SSH Authentication (Key Authentication Only)

- SSH **password authentication is disabled**.
- **SSH public key (key authentication) only** is accepted.
- Please **register your SSH public key** at the time of application (or deployment).
  If not registered, you will not be able to log in for the first time.

---

## Template Common Specifications

- 64-bit (x86_64 / amd64)
- Cloud-init compatible by default (automatic configuration of initial user / SSH key / network, etc.)
- qemu-guest-agent compatible (stabilization of IP display, shutdown, etc.)
- After the first startup, please perform OS updates and middleware installation yourself

---

## About ISO Bring-Your-Own Installation

You can install OSs not listed here by bringing your own ISO.
However, with ISO installation, **some automatic configurations such as cloud-init may not work**.

---

## Recommended Templates (For Production / Long-Term Operations)

If you're unsure, we recommend choosing from the following first.

| OS | Recommended Version | Features | Recommended For |
| --- | --- | --- | --- |
| Ubuntu Server | 24.04 LTS | LTS (Long-Term Support) / High versatility | Web/AP, Docker, general-purpose use |
| Ubuntu Server | 22.04 LTS | Compatibility-focused (for existing assets) | Migration from existing environments, fixed-requirement configurations |
| Debian | 13 (stable) | Stable, lightweight, server standard | Web/AP, DB, long-term stable operations |
| Debian | 12 (oldstable) | Previous stable version (compatibility tier) | Debian 12-based configurations, migration/validation |
| AlmaLinux | 10.X, 9.x | RHEL-compatible (enterprise standard) | Enterprise systems, commercial middleware |
| Rocky Linux | 10.X, 9.x | RHEL-compatible (strong in operations standardization) | Enterprise use, robust operations, standardization |

---

## CentOS Stream / Fedora (Testing to Production: If Use Case Matches)

Strong for latest versions and testing purposes, but please confirm your operations policy beforehand.

| OS | Recommended Version | Features | Cautions |
| --- | --- | --- | --- |
| CentOS Stream | 10 | Intermediate following "slightly ahead" of RHEL (rolling-biased) | Due to specification changes, Alma/Rocky is recommended for production |
| Fedora Linux | 43 | Fast adoption of latest technologies | Support period is relatively short. For testing and development |

---

## Lightweight Templates (Minimal)

For use cases where you want to run with minimal configuration and high speed.

| OS | Recommended Version | Features | Recommended For |
| --- | --- | --- | --- |
| Alpine Linux | 3.23.x | Ultra-lightweight, fast, simple | Small APIs, proxies, use-case-specific VMs |
| Alpine Linux | 3.22.x | Previous stable series | Compatibility-focused, migration from existing Alpine environments |

---

## Template Update Policy

- OS templates are updated periodically **on a best-effort basis** in line with upstream updates.
- **We do not provide EOL (end-of-life) OS as a general rule.**
- If you need an older version (for migration, validation, etc.), please **contact us via [support ticket](https://bestnetllc.co.jp/en/encyclopedia/support-ticket-en/)**.

---

## Which One Should I Choose? (If Unsure)

- If unsure: Ubuntu 24.04 LTS
- Stable and lightweight: Debian 13
- Enterprise operations, RHEL-compatible: AlmaLinux 9 / Rocky Linux 9
- Slightly ahead of RHEL, testing purposes: CentOS Stream 10
- Want to try the latest features: Fedora Linux 43
- Ultra-lightweight: Alpine Linux 3.23.x