How to protect against brute-force attacks on a Mikrotik router

MikroTik routers are widely used in home, business, and ISP networks due to their flexibility and powerful RouterOS features. However, like any network device exposed to the internet, they can become targets of DoS (Denial of Service) attacks. They can also be vulnerable to brute-force login attempts. It is crucial to protect against brute-force attacks to safeguard your network security.

Tips: Protect Against DoS on MikroTik

These attacks can overwhelm your network or compromise your router’s security by repeatedly guessing credentials. Fortunately, MikroTik offers several tools and techniques to help detect and mitigate these threats. By applying security measures, you can protect your MikroTik against brute-force attacks and safeguard your network.

1. Limit Access to Winbox, Web, and SSH

• Restrict management access to trusted IP addresses only: /ip service set winbox address=YOUR-IP-ADDRESS/32 /ip service set www address=YOUR-IP-ADDRESS/32 /ip service set ssh address=YOUR-IP-ADDRESS/32

2. Enable Connection Limits

• Drop suspicious connections with too many requests: /ip firewall filter add chain=input protocol=tcp connection-limit=30,32 action=drop

3. Drop Invalid Packets

/ip firewall filter add chain=input connection-state=invalid action=drop

4. Block Port Scanning

/ip firewall filter add chain=input protocol=tcp psd=21,3s,3,1 action=add-src-to-address-list address-list=port_scanners address-list-timeout=1d
/ip firewall filter add chain=input src-address-list=port_scanners action=drop

5. Dynamic Address Lists

• Automatically block IPs behaving suspiciously.

6. SYN Flood Protection

/ip firewall filter add chain=input protocol=tcp tcp-flags=syn connection-limit=100,32 action=drop

7. Rate-Limit ICMP Requests

/ip firewall filter add chain=input protocol=icmp limit=5,10 action=accept
/ip firewall filter add chain=input protocol=icmp action=drop

8. Careful Use of FastTrack

• Temporarily disable FastTrack during attacks to enforce firewall rules.

9. Keep RouterOS Updated

• Stay current with MikroTik’s firmware and security patches.

10. Monitor Logs and Network Behavior

• Use MikroTik’s tools like Torch or Log Viewer to monitor potential attack attempts.

Tips: Protect Against Brute-Force on MikroTik

In addition to DoS, many attackers use brute-force methods to gain access via SSH, Telnet, FTP, or Winbox. Implementing strategies specific to brute-force protection is essential to secure your MikroTik network.

11. Disable Unused Services

• Turn off any services you don’t use to reduce attack surfaces: /ip service disable telnet /ip service disable ftp /ip service disable www /ip service disable api

12. Use Strong Passwords and Change Default Username

• Create a strong password and disable or rename the default “admin” account. This is crucial to protect against brute-force attacks on your MikroTik: /user add name=secureadmin group=full password=STRONGPASS /user remove admin

13. Block Repeated Login Failures Using Address Lists

• Dynamically detect and block IPs attempting multiple failed logins: /system logging add topics=login action=memory

Then create firewall rules like:

/ip firewall filter add chain=input protocol=tcp dst-port=22,8291,21,23 \
  src-address-list=brute_blacklist action=drop

/ip firewall filter add chain=input protocol=tcp dst-port=22,8291,21,23 \
  src-address-list=brute_stage2 action=add-src-to-address-list \
  address-list=brute_blacklist address-list-timeout=1d

/ip firewall filter add chain=input protocol=tcp dst-port=22,8291,21,23 \
  src-address-list=brute_stage1 action=add-src-to-address-list \
  address-list=brute_stage2 address-list-timeout=1h

/ip firewall filter add chain=input protocol=tcp dst-port=22,8291,21,23 \
  action=add-src-to-address-list address-list=brute_stage1 address-list-timeout=15m

This logic tracks IPs trying multiple logins in short intervals and gradually escalates the block duration.

14. Use Port Knocking or VPN for Remote Management

• Hide or close ports completely. Open them only using port knocking. Access your router exclusively via a secure VPN.

Securing your MikroTik router from DoS and brute-force attacks is crucial for maintaining a stable and secure network. By properly configuring firewall rules, you can greatly reduce the chances of an attack succeeding.

Protect against brute-force attacks on MikroTik devices by restricting management access, too. Use dynamic protections like address lists. Regular monitoring, firmware updates, and enforcing strong login practices complete a solid security posture. MikroTik gives you the tools—you just need to apply them smartly.

In today’s interconnected world, cybersecurity threats are everywhere — especially for networks, websites, and systems exposed to the internet. Two common types of attacks that organizations and individuals face are DoS (Denial of Service) attacks and Brute-Force attacks. These attacks serve different purposes. They also use different methods. However, both can seriously impact your network, devices, or services if left unprotected. Understanding these attack types is crucial for defending your systems effectively.

1. What is DoS (Denial of Service) Attack?

🛑 Definition:

A DoS attack occurs when an attacker attempts to overwhelm a network, server, or device. This could be a router or website. The attacker floods it with a massive amount of traffic or requests. This action causes the system to slow down or crash.

📌 Purpose:

• To disrupt services and make them unavailable to legitimate users.
• Often used to take down websites, online services, or networked devices.

🔧 How It Works:

• The attacker sends a large volume of traffic (e.g., pings, HTTP requests) to the target.
• The system cannot handle the overload, causing performance issues or complete failure.

🔥 Common Types of DoS:

• SYN Flood
• UDP Flood
• ICMP (Ping) Flood
• HTTP Flood

⚠️ Impact:

• Website downtime
• Network slowdowns
• Service interruption
• Business or financial losses

2. What is a Brute-Force Attack?

🔓 Definition:

A Brute-Force attack occurs when an attacker attempts to guess a username and password. They try every possible combination. This continues until they obtain the correct one.

📌 Purpose:

• To gain unauthorized access to accounts, devices, or systems.
• Common targets: admin panels, SSH servers, Wi-Fi networks, email accounts.

🔧 How It Works:

• The attacker uses a script or automated tool to try thousands (or millions) of password combinations.
• Weak or common passwords are cracked quickly.
• Once access is gained, the attacker can steal data, install malware, or take over the system.

🔐 Types of Brute-Force Attacks:

• Simple brute-force: Trying all combinations (e.g., 123456, password).
• Dictionary attack: Tries known passwords from a list.
• Credential stuffing: Uses leaked usernames/passwords from previous breaches.

⚠️ Impact:

• Unauthorized access to sensitive data
• Account hijacking
• System compromise
• Data theft or manipulation

Key Differences: DoS vs Brute-Force

Feature	DoS Attack	Brute-Force Attack
Goal	Disrupt service / crash system	Gain unauthorized access
Method	Flooding with traffic	Trying many passwords/logins
Impact	Makes services unavailable	Compromises accounts or devices
Detection	High CPU usage, slowdowns, system failure	Failed login attempts, locked accounts
Prevention Tools	Firewalls, traffic filters, rate limiting	Strong passwords, login attempt limits, 2FA

Conclusion

Both DoS and Brute-Force attacks are serious cyber threats, but they serve very different purposes. A DoS attack aims to disrupt or disable your service. A Brute-Force attack tries to break into your system by guessing credentials. Understanding these attacks helps you better secure your network.

You can use appropriate defense measures, such as firewalls, rate limiting, account lockouts, and multi-factor authentication. The key to protection is preparation. By identifying vulnerabilities early, you can apply smart security practices. This way, you can prevent both types of attacks from compromising your system.