Exam N10-008 topic 1 question 113 discussion

Enforce firewall rules: Firewall rules are used to dictate what traffic can pass between the firewall and the internal network. Three possible actions can be taken based on the rule’s criteria: block the connection (explicit deny), accept the connection, or allow the connection if conditions are met (such as it being secured). It is this last condition that is the most difficult to configure, and conditions usually end with an implicit deny clause. An implicit deny clause means that if the proviso in question has not been explicitly granted, access is denied.

C. Implicit deny is normally applied as the LAST rule in a firewall. Implicit deny is a default rule that denies all traffic that does not match any of the other rules. This means that any traffic that is not explicitly allowed by a previous rule will be blocked by the firewall. It is important to have this rule as the last rule to ensure that no unauthorized traffic can pass through the firewall.

This question is definitely checking your comprehension of the order of operations in firewalls rules - where your implicit deny should always be last, so the prior rules can be considered first/in order.

With implicit deny rule set, it will be found @ the bottom of an IP access-list. Anything not mentioned in the ACL rule-set is to be denied by default, thus acting like a Whitelist for confidentiality.

C. Implicit deny An implicit deny rule is a catch-all rule that denies all traffic that is not specifically allowed by other rules in the firewall. It is typically applied as the last rule in the firewall's configuration to ensure that any traffic that is not explicitly permitted by other rules is blocked. A. Secure Simple Network Management Protocol (SNMP) is a protocol that is used to manage network devices. B. Port security is a feature that is used to restrict access to a switch port based on the MAC address of the device that is connected to the port. D. DHCP snooping is a security feature that is used to prevent unauthorized DHCP servers from being connected to a network.

In firewalls, implicit deny is the default configuration that blocks traffic that doesn't match a set of rules established in advance.