Learn more about pfSense Firewall Default Deny Rule IPv4. Our pfSense Support team is here to help you with your questions and concerns.

pfSense Firewall Default Deny Rule IPv4 | An Intro

Did you know that in pfSense, the default deny rule for IPv4 is automatically present in the firewall rule set?

This rule acts as a catch-all rule at the bottom of the rule list on each interface. In other words, it blocks all incoming traffic that does not match any of the defined allow rules above it.

It is a safeguard to make sure that no unwanted or unauthorized traffic is allowed into our network by default.

Let’s take a look at the default deny rule for IPv4 in pfSense:

• The default deny rule is always placed at the bottom of the firewall rule list for each interface. Rules are evaluated from top to bottom. So if no allow rule matches incoming traffic, it will be denied by this rule.
• Rule Configuration:
  • Protocol: All (it applies to all IP protocols).
  • Source: Any (it blocks traffic from any source IP address).
  • Destination: Any (it blocks traffic to any destination IP address).
  • Port: Any (it blocks traffic to any port).
• By default, the default deny rule logs denied traffic. However, it also generates a large number of log entries in busy networks. So, we have to adjust the logging settings for this rule.
• Additionally, we can customize the rule or add specific deny rules as needed.
• Furthermore, if we create allow rules for certain types of traffic or services, these rules will be placed above the default deny rule.
• It is also considered a best practice to leave the default deny rule in place to block all traffic by default.
• pfSense also includes a similar default deny rule for IPv6 traffic.

Let us know in the comments if you need any more help with the default deny rule for Ipv4 in pfSense.

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Conclusion

In brief, our Support Experts introduced us to the default deny rule for Ipv4 in pfSense.