Palo Alto Networks Certified Cybersecurity Entry-level Technician (PCCET)Cybersecurity FundamentalsMedium
A network administrator is configuring a new firewall for a data center. The policy explicitly states that all traffic originating from the internal network destined for any external IP address on port 80 (HTTP) should be allowed, while all other outbound traffic is blocked by default. Which type of firewall rule is primarily being implemented to block the 'other outbound traffic'?
- AImplicit Deny Rule
- BStateful Inspection Rule
- CExplicit Allow Rule
- DNAT Rule
Show answer & explanationAnswer & explanation
Correct answer: A. Implicit Deny Rule
An implicit deny rule is a default firewall rule that blocks any traffic that is not explicitly allowed by other rules. In this scenario, after allowing port 80 traffic, all 'other outbound traffic' is blocked by default, indicating an implicit deny.
Why the other options are wrong
- B. Stateful inspection tracks connection states but doesn't define the default allow/deny policy.
- C. Explicit allow rules specifically permit traffic, but the question asks about blocking 'other' traffic.
- D. NAT (Network Address Translation) rules change IP addresses and ports, not primarily for blocking general traffic.
Implicit Deny
A fundamental firewall security principle where any traffic not explicitly permitted by a rule is automatically denied.
- Often the last rule in a firewall policy.
- Ensures no unintended traffic passes through.
- A crucial component of a 'least privilege' network security posture.
Memory trick: If it's not allowed, it's denied by default (implicitly).