Inbound vs Outbound Firewall Rules – ManageEngine

Each organization should carefully configure its firewall rules to monitor incoming and outgoing network traffic and minimize the risk of falling victim to attacks.

To manage inbound and outbound

firewall rules effectively, it is important to understand the difference between inbound and outbound traffic.

What is inbound traffic?

Traffic that does not originate within the network but that you want to enter the network perimeter is inbound traffic. This traffic can be directed from a web browser, an email client, an application requesting a service such as FTP or SSH, etc. to your network.

What is outbound traffic?

Unlike inbound traffic, outbound traffic originates within your network. This traffic comes from network users to access websites and other resources that are outside the network perimeter.

What are inbound firewall rules?

  • Inbound firewall rules protect your network by blocking traffic from known malicious sources and thus prevent malware attacks, DDoS attacks, and more
  • .

  • Malicious traffic can be blocked based on ports, traffic type, or IP addresses.

Tips for configuring inbound firewall rules

: Always check the source of

  • traffic: source IP, the country from which it originates, whether it arises from a single source or multiple sources, which ports they request
  • access to, etc.

  • Type an inbound rule to deny any type of access to malicious IP addresses
  • .

  • Use threat intelligence sources to find out if an IP is malicious or not.
  • Check if the malicious IP has targeted any applications on a device connected to your network by performing a port scan or detecting anomalies that occur in applications containing vital information.
  • Ensure that

  • the host-level firewall is configured on critical servers and databases that contain sensitive information so that any type of communication diverted through vulnerable ports is blocked on particular hosts. This is to strengthen security at the intranet level if the attacker is an insider.

What are

outbound firewall rules? Outbound firewall rules are firewall policies that

  • define the traffic that can leave your network through secure ports to reach legitimate destinations
  • .

  • They stop requests sent to malicious websites and untrusted domains
  • .

  • Configuring outbound firewall rules can prevent data exfiltration.
  • Outbound firewall rules can be adjusted to scan the content of emails or files containing sensitive information that are sent from your network.
  • They closely monitor transmission protocols such as Internet Message Access Protocol (IMAP), Post Office Protocol version 3 (POP3), and Simple Mail Transfer Protocol (SMTP).

Tips for configuring outbound firewall rules:

  • Always monitor traffic leaving your network. Know the source of outbound traffic.
  • Check if the destination of the traffic is known to be malicious.

Regularly monitor traffic leaving your network. Base the normal behavior pattern and set up alerts in your security solution to notify you about any unusual spikes in the volume of traffic or data leaving your network.

A typical firewall should regulate inbound and outbound

traffic by employing inbound and outbound firewall rules. Any change to these rules can cause chaos within the network. Therefore, it is essential to monitor the changes that occur in these rules and determine if they are legitimate.

EventLog Analyzer, a comprehensive log management solution, helps you monitor changes to these firewall rules and other firewall settings in real time. Get detailed reports on who made the change, when it was made, and from where to determine its legitimacy. Also, receive instant email and SMS notifications for any unauthorized changes. Click here to learn more about the solution.

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