Running a VPS gives you full control — but it also comes with responsibility. Whether you’re hosting with a budget VPS or a high-performance Ryzen VDS from Hosteons, security should always be a top priority.

Automated bots and malicious actors are constantly scanning servers looking for open doors. The good news? With just a few simple firewall rules, you can block 90% or more of common attacks — no advanced security knowledge needed.

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🚧 Step 1: Deny All by Default

Your firewall should start from a “zero trust” position. Block all incoming traffic unless explicitly allowed.

iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT

This is the safest starting point for VPS security.

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✅ Step 2: Open Only the Ports You Need

For most users, these are the essential services:

iptables -A INPUT -p tcp --dport 22 -j ACCEPT   # SSH
iptables -A INPUT -p tcp --dport 80 -j ACCEPT   # HTTP
iptables -A INPUT -p tcp --dport 443 -j ACCEPT  # HTTPS

If you’re using a custom SSH port, be sure to update that here.

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🛡️ Step 3: Rate-Limit SSH to Stop Brute-Force Attacks

SSH is the most frequently targeted service. Add a rate-limiting rule to block repeated login attempts:

iptables -A INPUT -p tcp --dport 22 -m state --state NEW -m recent --set
iptables -A INPUT -p tcp --dport 22 -m state --state NEW -m recent --update --seconds 60 --hitcount 3 -j DROP

This prevents bots from guessing passwords through brute force.

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🧼 Step 4: Drop Invalid or Malicious Packets

Invalid packets are often used in scanning or attack attempts. Drop them:

iptables -A INPUT -m state --state INVALID -j DROP

This helps prevent certain types of kernel-level exploits and misbehavior.

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🔁 Step 5: Allow Loopback and Established Connections

Let your server communicate with itself and continue existing sessions:

iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

Without these, things like internal services and return traffic might break.

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👀 Step 6: (Optional) Block Ping (ICMP)

Ping isn’t harmful by itself, but attackers use it to detect live servers. You can hide yours:

iptables -A INPUT -p icmp --icmp-type echo-request -j DROP

Note: avoid this if you use ping-based monitoring tools.

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💡 Bonus: Use CSF for Easier Firewall Management

Not comfortable with command-line tools? Hosteons VPS plans fully support CSF (ConfigServer Security & Firewall)— a beginner-friendly, feature-rich firewall system with:

• Easy interface via DirectAdmin
• Built-in brute-force detection
• Country-level blocking
• Port scan detection
• Daily logs and alerts

Perfect for users who want simplicity without sacrificing power.

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🔄 Don’t Forget to Save Your Rules

After setting your rules, make sure they persist after a reboot.

On Ubuntu/Debian:

iptables-save > /etc/iptables/rules.v4

On CentOS/RHEL:

Use iptables-save along with persistent packages, or configure firewalld.

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🔐 VPS Security Starts with You

Whether you’re running a personal blog, game server, or production site on a VPS from Hosteons, implementing basic firewall rules should be your first line of defense.

These 6 rules are easy to set up and highly effective. For extra protection, consider:

• Enabling fail2ban
• Using SSH keys instead of passwords
• Running regular security updates

At Hosteons, we offer high-performance, SSD-powered KVM VPS and Ryzen VDS backed by robust network security and full root access — so you’re always in control.

🔒 Ready to launch your secure VPS?

👉 Explore our VPS plans now