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Definition of Bastion host

What is a bastion host?

A bastion host is a dedicated server specifically designed to withstand cyberattacks and provide secure access to a private network from an untrusted one, like the Internet. Positioned strategically at the network perimeter, typically outside a firewall or in a demilitarized zone (DMZ).

Imagine a fortified castle protecting the treasury from invaders. In the realm of network security, a bastion host plays a similar role, guarding the internal network from external threats.

How Bastion Host works

Let's delve deeper into its inner workings:

  1. A bastion host is strategically positioned at the network's edge, either just outside the firewall or within a DMZ. This placement keeps the rest of your internal network shielded while offering a controlled entry point.
  2. Unlike a regular server juggling various tasks, a bastion host is a minimalist. It only runs essential services needed for secure remote access, typically just SSH (Secure Shell) or RDP (Remote Desktop Protocol).
  3. Access to the bastion host is tightly controlled, often layered with multi-factor authentication (MFA). Think of it as a password check combined with a secret handshake – only authorized users with the right credentials gain entry
  4. Every action on the bastion host is meticulously documented. Logs are kept and monitored for suspicious activity, allowing security teams to identify and respond to potential threats quickly.
  5. Once inside the bastion host, users don't get free rein. Their access is carefully restricted to specific internal resources they require. It’s like the trusted guide who takes you through specific parts of the castle once you've been granted entry. This prevents unauthorized access to sensitive data or systems.

What is the difference between a firewall and a bastion host

Firewalls and bastion hosts are both security tools, but they serve distinct purposes:

A firewall acts as a wall, blocking unauthorized traffic based on predetermined rules. It's like the castle gatekeeper who decides who enters based on a set of criteria.

Bastion Host provides controlled access for authorized users through secure channels. 

While firewalls block unwanted traffic, bastion hosts enable secure access for authorized users. They work together to create a layered defense system for your network.

What is the difference between a VPN and a bastion host

Both VPNs and bastion hosts enable secure remote access, but their approaches differ:

  • A VPN creates a secure tunnel between a remote device and the internal network, encrypting all traffic passing through it. It's like a secret passageway, allowing authorized users to access the entire network directly.
  • A bastion host acts as a centralized gateway, controlling and monitoring all remote access through a single point. It's like a secure checkpoint for verified users before granting access to specific resources within the network.

Key Takeaways

  • Bastion hosts guard private networks from the internet.
  • They offer controlled entry points, only allowing authorized users with multi-factor authentication (MFA).
  • Unlike regular servers, they run only essential services for secure remote access (SSH, RDP).
  • Every action is logged and monitored for suspicious activity.
  • Users get access only to specific internal resources, not the entire network.
  • Differences: Firewall — Blocks unauthorized traffic like a gatekeeper with pre-defined rules; VPN — Creates a secure tunnel for direct access to the entire network, like a secret passage.

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