This should be the first thing that an IS auditor considers when evaluating firewall rules, because it defines the objectives, standards, and guidelines for securing the organization’s network and information assets. The firewall rules should be aligned with the organization’s security policy, and reflect the level of risk and protection required for each type of network traffic, system, or data. The IS auditor should compare the firewall rules with the security policy, and identify any discrepancies, gaps, or conflicts that could compromise the security or performance of the network.

The other options are not as important as the organization’s security policy when evaluating firewall rules:

The number of remote nodes. This is a factor that may affect the complexity and scalability of the firewall rules, but it is not a primary consideration for the IS auditor. Remote nodes are devices or systems that connect to the network from outside locations, such as teleworkers, mobile users, or branch offices. The IS auditor should ensure that the firewall rules provide adequate security and access control for remote nodes, but this depends on the organization’s security policy and business needs.

The firewalls’ default settings. These are the predefined configurations that come with the firewall devices or software, and that determine how they handle network traffic by default. The IS auditor should review the firewalls’ default settings, and verify that they are appropriate and secure for the organization’s network environment. However, the firewalls’ default settings may not match the organization’s security policy or specific requirements, and may need to be customized or overridden by firewall rules.

The physical location of the firewalls. This is a factor that may affect the placement and design of the firewall rules, but it is not a critical consideration for the IS auditor. The physical location of the firewalls refers to where they are installed or deployed in relation to the network topology, such as at the network perimeter, between network segments, or on individual hosts. The IS auditor should ensure that the firewall rules are consistent and coordinated across different locations, but this depends on the organization’s security policy and network architecture.