Firewall Best Practices For MikroTik RouterOS Protecting Your Network

As we increasingly rely on the internet for work, communication, entertainment and more, it is essential that we understand how to keep our digital devices and information safe from harmful actors and cyber attacks. One of the most basic lines of defense is the firewall.

A firewall is a program or hardware device designed to prevent unauthorized access to or from a private network. Its main function is to act as a barrier between a secure internal network and outside networks like the internet, which may not be trusted. The firewall monitors and controls incoming and outgoing network traffic based on predetermined security rules.

How does a firewall work?

The basic concept behind a firewall is simple: all incoming and outgoing traffic is examined and filtered based on defined criteria and permissions. The firewall analyzes the data packets that are moving back and forth between the internet and the network it is protecting. Based on the pre-defined rules, it will either allow or block these packets of data.

Some of the common criteria and permissions used by firewalls to control traffic include:

Source and destination IP addresses
Source and destination port numbers
Protocol type (HTTP, FTP, SSH, etc.)
Incoming and outgoing traffic patterns
Packet size and data payload

All these factors, and more, are used by the firewall to determine if a data packet should be allowed to pass through the network, or if it should be blocked for security reasons.

Types of firewalls

There are several different types of firewalls available today, each with its unique advantages and limitations. Some of the most common types include:

Packet filtering

Packet filtering firewalls are relatively simple and work by examining incoming and outgoing network packets based on a set of predefined rules. The firewall may allow or block the packet based on criteria like the packet's IP address, source port number, destination port number, and protocol type. This type of firewall operates at the network layer of the OSI model and is commonly used in routers.

Stateful inspection

Stateful inspection firewalls offer greater security than packet filtering firewalls by keeping track of the state of network connections. This means that each incoming packet is checked to determine if it is part of an established connection, rather than just a random data packet. This type of firewall operates at the network layer and can examine packet headers and payloads to identify specific types of traffic.

Proxy firewalls

Proxy firewalls work at the application layer of the OSI model and examine application-specific traffic like HTTP, SMTP, and FTP. A proxy firewall sets up a proxy server to act as an intermediary between an internal network and the internet. When a client sends a request to access a service or website on the internet, the proxy server processes the request on behalf of the client, applying security policies and controls before forwarding the request to the remote service. The remote service responds to the proxy server, which then forwards the response back to the client.

Unified Threat Management (UTM) firewalls

UTM firewalls combine several security features into a single security appliance. These features may include a firewall, antivirus, intrusion detection and prevention systems, and content filtering. UTM firewalls can be a cost-effective solution for small to medium-sized businesses that need a comprehensive security solution but don't have the budget or resources to implement and manage multiple security systems.

Read also

Advantages of using a firewall

There are several key advantages to using a firewall to protect your network and devices:

Block unauthorized access: A firewall can prevent unauthorized access to your internal network by controlling incoming and outgoing traffic.
Stop harmful traffic: A firewall can block incoming traffic that contains malware, viruses, or other harmful payloads.
Provide remote access: Some firewalls allow remote access to internal resources, like company servers, while still maintaining security controls.
Control bandwidth usage: A firewall can be used to control bandwidth usage by blocking or throttling certain types of traffic.
Compliance: Many industries and organizations must comply with strict regulations related to data security. The use of firewalls can help meet these compliance requirements.

Limitations of firewalls

While firewalls are an important security tool, there are some limitations to their effectiveness. Some of the common limitations include:

Cannot protect against all types of attacks: Firewalls can only block traffic that they are specifically configured to block. New types of attacks or techniques may be able to bypass firewall protections.
Cannot protect against insider threats: Firewalls cannot protect against malicious or careless insiders who have authorized access to the network.
Cannot protect an unsecured endpoint: If an endpoint device like a laptop or mobile phone is not secure, a firewall cannot protect it from malware or viruses.
Can introduce performance issues: In some cases, a firewall can introduce performance issues, especially if the firewall is not configured properly or is overloaded with traffic.

Conclusion

A firewall is an essential component of any cybersecurity strategy. By monitoring and controlling incoming and outgoing network traffic, firewalls can prevent unauthorized access to a private network and protect against harmful traffic. There are several types of firewalls to choose from, each with its unique advantages and limitations. While firewalls are not a foolproof solution, they are an important first line of defense against cyber threats.

As we continue to rely on the internet for more aspects of our lives, it's crucial that we take the necessary steps to protect our digital devices and information. By understanding how firewalls work and choosing the right type of firewall for your needs, you can help ensure that your vital information and assets are safe and secure, both now and in the future.