Cloud Security Tips: The Network Lockdown Basics that Hyperscalers Don’t Teach

Cloud

The three big cloud companies, called hyperscalers—AWS, Google Cloud, Microsoft Azure—have built massive platforms, but their cloud security documentation often feels like it was written by engineers for engineers, buried under layers of complexity.

For the average VPS user, most cloud security breaches aren’t the result of sophisticated nation-state attacks or zero-day exploits. They happen because basic security protocols were missed. We’re talking about open ports that should have been closed, default credentials that were never changed, or misconfigured access controls that nobody noticed until it was too late. The fundamental best practices of cloud network security aren’t complicated, but they do need to be explained clearly and made accessible to each VPS user.

That’s what this guide is for. The best part is that most of these tools are built directly into the Kamatera console, making robust cloud security measures more accessible without needing to hire an expensive security team. These network lockdown practices will significantly reduce attack surface and keep us all safe from intruders and bad actors.

Key takeaways

Adopting a secure cloud posture doesn’t require a specialized security team or a massive budget. By focusing on these fundamental network lockdown practices, you can protect your Kamatera environment from the vast majority of common threats.

• Use a default deny firewall policy to block all traffic except what is strictly necessary.
• Enforce the principle of least privilege for every user, service, and API key.
• Disable SSH password logins in favor of public-private key pairs.
• Move SSH to a custom port or use a VPN gateway to eliminate automated scans.
• Hide databases from the public internet using private IP addresses within a VPC.
• Utilize a bastion host as a single, hardened gateway for all administrative tasks.
• Separate public and private traffic layers to prevent attackers from moving laterally.
• Encrypt data in transit for both external and internal communication.
• Remove hardcoded secrets from code and use environment variables or a vault.
• Set up continuous monitoring and alerting to stay ahead of potential breaches.
• Automate security patches and updates to close known vulnerabilities quickly.

Start with the principle of least privilege

If there’s one cloud security concept worth internalizing before anything else, it’s this: every user, service, and system in your network should have access to exactly what it needs and nothing more.

Default deny is the specific application of PoLP to your Kamatera firewall. Instead of trying to identify and block bad traffic (which is an infinite list), you block all traffic by default and only “privilege” the specific data packets you know are safe and necessary.

Apply least privilege everywhere, not just your firewall. When creating user accounts, assign only the specific permissions required for their role. When configuring service accounts, limit scope to the exact resources they access. When setting up API keys, restrict them to specific actions and IP addresses where possible.

Audit your permissions regularly. People change roles, projects end, and services get deprecated—but weak access controls rarely get cleaned up automatically. Schedule quarterly reviews to revoke unnecessary permissions and you’ll dramatically reduce your exposure.

Stop exposing SSH

SSH on port 22, open to the entire internet, is one of the most targeted attack surfaces in cloud computing. Within minutes of deploying a new VPS, automated scanners will find it and start hammering it with credential stuffing attacks.

Here’s three changes you should make immediately:

1. Disable password authentication. Force SSH key-based authentication only. Public-private key pairs are exponentially harder to brute-force than passwords. If you haven’t already generated SSH keys and added them to your servers, do it today.
2. Change the default SSH port. Move SSH from 22 to something non-standard—2222, 2244, or any port above 1024 that isn’t used by another service. This won’t stop a determined attacker, but it eliminates the enormous volume of automated scanning that targets port 22 specifically.
3. Implement a tool like fail2ban. This monitors your SSH logs and automatically blocks IP addresses that repeatedly fail authentication attempts. Brute-force attacks become largely ineffective when the attacker’s IP gets banned after five failed attempts.

If you have the option, the cleanest solution is to put SSH behind a VPN entirely. Only allow SSH connections from your VPN network, and keep SSH completely closed to the public internet. Kamatera provides robust VPN deployment options, including one-click installations for OpenVPN and UTunnel, allowing you to establish a secure gateway to your private network in minutes. This is how security-conscious organizations operate, and it’s simpler to set up than most people think.

Bastion hosts and jump boxes

Here’s a scenario that plays out more often than it should. A developer needs quick access to a production server, so they open SSH on port 22 (even though we just told you that it is one of the most targeted data security threats). Then another server needs the same. Then another. Before long, every machine in the fleet has a public management port open to the world, and the attack surface has grown into something enormous.

The professional alternative is simpler than it sounds: give your cloud infrastructure exactly one front door, and make that door exceptionally hard to break through.

A bastion host, sometimes called a jump box, is a single, heavily hardened server that acts as the only public entry point into your infrastructure. Every other server in your fleet has no public management ports open at all. From the internet’s perspective, they’re essentially invisible. The bastion is the only machine authorized to reach them for administrative purposes.

The workflow is straightforward. You SSH into the bastion from your local machine. This is the only server with a public-facing management port, and even that should be locked down to your specific IP address. Once you’re authenticated and inside, you pivot from the bastion to your internal servers using their private IP addresses. Those internal servers are configured to accept management traffic only when it originates from the bastion’s internal IP.

Segment your network

One compromised server shouldn’t mean every server is compromised. With some cloud security controls like network segmentation, you can limit the damage of a security incident by separating different parts of your infrastructure into isolated network zones.

The classic best practices approach is a three-tier architecture: a public-facing layer for your web servers, a private application layer for your business logic, and a database layer with no public connectivity whatsoever. Each layer can only communicate with the layer directly adjacent to it, using tightly controlled rules.

In cloud terms, this means using private networks or VLANs to create separate environments for different functions. Your web servers sit in a public subnet. Your application servers sit in a private subnet, only reachable from the web tier. Your databases sit in a data subnet, only reachable from the application tier.

The result of this setup is that even if an attacker compromises your web server, they can’t directly access your database. They’d need to pivot through multiple layers, each with its own access controls, and that creates detection opportunities at every step.

Segmentation isn’t just for large enterprises. Even a small deployment with three or four servers benefits from separating public-facing components from internal ones. Kamatera makes it easy to configure private networks between instances.

VPCs: A private network inside your network

If you’re not using a virtual private cloud, your infrastructure is probably more exposed than you realize.

By default, most cloud providers assign a public IP address to every server you spin up. That seems convenient until you think about what it actually means: your database, your application servers, your internal APIs—all of them potentially reachable from the public internet if a firewall rule is missing or misconfigured.

A VPC fixes this by providing a robust foundation for access management, giving you a private, isolated network for your cloud data that belongs entirely to you. Servers inside it communicate with each other at high speed over a private connection that never touches the public internet. From the outside, they simply don’t exist.

The most important thing you can do with VPC isolation is take your database fully off the public internet. The configuration is three steps. Assign your database a private IP address only. Configure its firewall to accept connections exclusively from the internal IP of your application tier. Remove any public network interface entirely. Done correctly, this means a remote attacker cannot reach your database under any circumstances, regardless of what vulnerabilities exist in the database software itself. You can’t exploit what you can’t reach.

If your database currently has a public IP address, fixing that should be your next priority after finishing this article.

Encrypt everything in transit

Unencrypted traffic is readable by anyone on the network path between sender and receiver. In a cloud environment, that includes potential attackers who’ve found their way into your network.

All cloud services in your infrastructure that communicate over a network should use encrypted connections. Your web application needs HTTPS. Let’s Encrypt has made SSL/TLS certificates free and automatically renewable, so there’s genuinely no excuse for running HTTP in production anymore.

But HTTPS for public-facing apps is just the beginning. Internal service-to-service communication should also be encrypted. Your application server connecting to your database should use SSL. Your application connecting to your cache should use TLS. Your microservices talking to each other should encrypt data.

Internal data encryption often gets deprioritized because people assume private networks are safe. They’re safer, but they’re not immune. A misconfigured firewall rule, a compromised internal service, or a supply chain attack can all lead to an attacker sitting inside your private network reading unencrypted traffic. Encryption-in-transit makes that significantly harder to exploit.

Treat your secrets like security risks

Hardcoded credentials are the unsung villain of cloud security. From database passwords sitting in plain text in your application code to API keys committed to public GitHub repositories, it’s the cyber equivalent of showing your underwear.

This happens constantly. It’s how major data breaches start, and it’s completely preventable.

Use a secrets management solution. HashiCorp Vault is the gold standard for complex environments. Even a well-configured environment variables approach is vastly better than hardcoded credentials.

The key behaviors to enforce: Never commit credentials to version control under any circumstances. Rotate API keys and passwords regularly. Use separate credentials for each environment (development, staging, production). Audit which systems have access to production secrets and aggressively limit that list.

Set up secret scanning on your repositories. Tools like GitGuardian or GitHub’s built-in secret scanning will alert you if credentials accidentally get committed. Consider these alerts high priority. Treat every accidental exposure as a data breach until proven otherwise.

Enable logging (and actually look at it)

You can’t defend against threats if you can’t detect them. Comprehensive logging gives you visibility into what’s happening in your infrastructure. It’s often the difference between detecting a data breach early and discovering it months later.

Log everything meaningful: authentication attempts (both successful and failed), firewall rule matches, API calls, privilege escalations, and cloud configuration changes. Most cloud providers offer centralized logging services that aggregate logs from across your infrastructure.

But here’s the part that often gets skipped: You need to actually review those logs. Raw logs are noisy and hard to parse, but setting up basic alerting for suspicious patterns makes this manageable. Alert on multiple failed authentication attempts, login attempts from unusual geographic locations, after-hours access to sensitive systems, and unexpected spikes in outbound traffic.

Set a reminder to manually review your access logs monthly. You’ll develop an intuition for what normal looks like in your environment, and anomalies will start to stand out. Many compromises leave traces in logs weeks before attackers gain unauthorized access and cause real damage. Regular review gives you the opportunity to catch them early and protect sensitive data.

Keep everything updated

This one sounds obvious, but unpatched software is consistently one of the leading causes of costly data breaches. A vulnerability gets discovered and published, a patch gets released, but thousands of servers stay unpatched for months.

Establish a clear update schedule. Security patches should be applied within days of release, not weeks or months. Other updates can follow a regular weekly or bi-weekly cadence. For critical cloud infrastructure, test updates in a staging environment before applying to production.

Enable automatic security updates for your operating system where possible. Most Linux distributions support automatic security patching that handles OS-level vulnerabilities without manual intervention.

Track your dependencies. The software your application depends on has vulnerabilities just like the OS does. Use dependency scanning tools to identify outdated packages with known vulnerabilities. Many data breaches in recent years have come through vulnerable dependencies, rather than the application code itself.

Put it all together

Cloud security is a combination of layers. Each one you add makes a cyber threat harder to execute and easier to detect. Implementing all these cloud security tips will create an environment where opportunistic attackers move on to easier targets, and sophisticated attackers leave enough traces to get caught.

But before you spend any money on sophisticated security tooling for your cloud workloads, make sure the fundamentals are solid. Restrict your firewall rules. Use SSH keys. Segment your network. Encrypt data. Manage your secrets properly. Log, review, and update regularly.

These aren’t cutting-edge techniques. They’re the unglamorous blocking and tackling of security challenges that prevents the vast majority of real-world breaches. They’re also the practices that hyperscalers assume you already know, which means they’re often the ones nobody bothers to clearly explain.