EAP (Extensible Authentication Protocol) is a framework that allows different authentication methods to be used for network access. EAP is used for RADIUS/EAP authentication, which is a common method for authenticating domain users on domain computers using certificates. EAP requires that the RADIUS server, such as ClearPass Policy Manager (CPPM), validates the certificates presented by the clients and verifies their identity against an identity source, such as Windows AD. Therefore, the root certificate for the Windows CA that issues the certificates to the clients should have the EAP usage in the ClearPass CA Trust list.

Radsec (RADIUS over TLS) is a protocol that allows secure and encrypted communication between RADIUS servers and clients using TLS. Radsec is used for encrypting all communications between CPPM and the domain controllers, which act as RADIUS clients. Radsec requires that both the RADIUS server and the RADIUS client validate each other's certificates and establish a TLS session. Therefore, the root certificate for the Windows CA that issues the certificates to the domain controllers should have the Radsec usage in the ClearPass CA Trust list.

A beacon is a type of network traffic that is sent from a compromised device to a command and control (C2) server, which is a remote system that controls the malicious activities of the device . A beacon is used to establish and maintain communication between the device and the C2 server, as well as to receive instructions or exfiltrate data .

A common characteristic of a beacon is that it is periodic, meaning that it is sent at regular intervals, such as every few minutes or hours . This helps the C2 server to monitor the status and availability of the device, as well as to avoid detection by network security tools .

Another common characteristic of a beacon is that it is small and identically sized, meaning that it contains minimal or fixed amount of data, such as a simple acknowledgment or a random string . This helps the device to conserve bandwidth and resources, as well as to avoid detection by network security tools .

DNS tunneling is a technique that abuses the DNS protocol to tunnel data or commands between a compromised host and an attacker's server.DNS tunneling can be used to establish a command and control channel, which allows the attacker to remotely control the malware or exfiltrate data from the infected host1

The traffic capture in the exhibit shows some signs of DNS tunneling. The source IP address is 10.1.7.2, which is likely an internal host behind a firewall. The destination IP address is 8.8.8.8, which is a public DNS resolver. The DNS queries are for subdomains of badsite.com, which is likely a malicious domain registered by the attacker. The subdomains have long and random names, such as 0x2a0x2a0x2a0x2a0x2a0x2a0x2a0x2a.badsite.com, which could be used to encode data or commands.The DNS responses have large sizes, such as 512 bytes, which could be used to carry data or commands back to the host2

According to the AOS 10 documentation1, WIDS is a feature that monitors the radio spectrum for the presence of unauthorized, rogue access points and the use of wireless attack tools. WIDS can be configured at different levels, such as low, medium, high, or custom. The higher the level, the more checks are enabled and the more alerts are generated. However, not all checks are equally relevant or indicative of real threats. Some checks may generate false positives or unnecessary alerts that can overwhelm the administrators and reduce the effectiveness of WIDS.

Therefore, one step that could be recommended to reduce the number of email notifications is to change the WIDS level to custom, and enable only the checks most likely to indicate real threats. This way, the administrators can fine-tune the WIDS settings to suit their network environment and security needs, and avoid getting flooded with irrelevant or redundant alerts. Option C is the correct answer.

Option A is incorrect because sending the email notifications directly to a specific folder and only checking the folder once a week is not a good practice for security management. This could lead to missing or ignoring important alerts that require immediate attention or action. Moreover, this does not solve the problem of getting too many emails in the first place.

Option B is incorrect because disabling email notifications for Rogue AP, but leaving the Infrastructure Attack Detected and Client Attack Detected notifications on, is not a sufficient solution. Rogue APs are unauthorized access points that can pose a serious security risk to the network, as they can be used to intercept or steal sensitive data, launch attacks, or compromise network performance. Therefore, disabling email notifications for Rogue APs could result in missing critical alerts that need to be addressed.

Option D is incorrect because disabling just the Rogue AP and Client Attack Detected alerts, as they overlap with the Infrastructure Attack Detected alert, is not a valid assumption. The Infrastructure Attack Detected alert covers a broad range of attacks that target the network infrastructure, such as deauthentication attacks, spoofing attacks, denial-of-service attacks, etc. The Rogue AP and Client Attack Detected alerts are more specific and focus on detecting and classifying rogue devices and clients that may be involved in such attacks. Therefore, disabling these alerts could result in losing valuable information about the source and nature of the attacks.