What Is a Bastion Host?

A bastion host is a special-purpose server designed and configured to withstand attacks while managing access to an internal or private network from an external network. It acts as a bridge, or "jump box," allowing authorized users to connect securely to a private network without exposing it to the public internet.

Often located in a demilitarized zone (DMZ) or outside the firewall, the bastion host serves as the gatekeeper to critical internal systems and resources. It typically runs minimal services, often just a single application, which helps reduce the attack surface for potential cyber threats. By managing and filtering access, a bastion host enhances the overall security posture of a network.

How a Bastion Host Works

A bastion host functions as an intermediary between a user and a private network, ensuring secure access. When an authorized user needs to connect, they use a secure channel like SSH (Secure Shell) to access the bastion host, which then verifies their identity. Once authorized, the user gains access to the internal network and its resources, while the private network remains protected from direct exposure to the public internet.

This setup is especially beneficial for organizations with remote or distributed teams. Bastion hosts provide secure access points, allowing employees to connect from various locations without compromising network security.

The Difference Between a Firewall and a Bastion Host

Firewalls and bastion hosts are both essential to network security, but they serve different roles. A firewall primarily blocks or filters unwanted traffic, preventing unauthorized access by monitoring network traffic based on predefined security rules, acting as a barrier between trusted and untrusted networks. In contrast, a bastion host enables secure, controlled access for authorized users, often serving as a proxy or jump server for remote employees or external partners. Together, they form a layered defense, with the firewall blocking unwanted traffic and the bastion host facilitating secure access for trusted users.

When Should a Bastion Host Be Used?

Bastion hosts are valuable for businesses in various scenarios, particularly when security and controlled access are critical. Here are some key use cases:

Secure Remote Access:

As remote work becomes more prevalent, the need for secure access to internal networks grows. Bastion hosts provide a secure gateway for employees to connect to the company's private resources from outside the office.

Network Segmentation:

Organizations often segment their networks to isolate critical resources. A bastion host can serve as the only access point to specific segments, ensuring that unauthorized users cannot directly connect to sensitive areas of the network.

Single Point of Access:

By centralizing access through a single bastion host, businesses can simplify access control management. This makes it easier to enforce security policies and monitor access to critical systems.

Conclusion

A bastion host is vital for businesses needing secure remote access and protection of sensitive data. Acting as a gatekeeper, it allows authorized users to access private networks while blocking threats. When combined with firewalls, it forms a robust, layered defense. Businesses should implement bastion hosts to ensure controlled access, particularly with remote workers, network segmentation, and strict security needs.

The NCA-5330, a 1U rackmount network appliance powered by AMD's EPYC™ 9004 Series Processor (Genoa/Bergamo), is an ideal bastion host for securing IT, OT, and CT networks. It efficiently supports various workloads, including application delivery, WAN optimization, DPI/IPS/IDS, and NGFW/UTM. With high per-core performance, reduced energy consumption, and minimized TCO, the NCA-5330 provides a powerful platform for ensuring secure, controlled access to private networks while accelerating workloads across enterprise and cloud environments.

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