BT Group Network Security Engineer Interview Questions and Answers

ASP packet capture is a method of capturing and analyzing network traffic to identify potential security threats.

• ASP stands for Application Service Provider.

• Packet capture involves capturing data packets as they travel across a network.

• ASP packet capture helps in monitoring network traffic for security purposes.

• Tools like Wireshark can be used for ASP packet capture.

VLAN stands for Virtual Local Area Network. It is a network technology that allows for segmentation of a single physical network into multiple virtual networks.

• VLANs help in improving network security by isolating traffic between different departments or groups.

• There are two main types of VLANs: Port-based VLANs and Tag-based VLANs.

• Port-based VLANs assign ports on a switch to different VLANs, while Tag-based VLANs use ...read more

Packet flow of ASA/FTD involves ingress, inspection, and egress stages.

• Ingress stage: Packet enters the ASA/FTD device through an interface.

• Inspection stage: Packet is inspected by access control policies, NAT rules, and VPN configurations.

• Egress stage: Packet exits the ASA/FTD device through an interface towards its destination.

• Example: Ingress - packet enters ASA/FTD through outside interface, Inspection - packet is ...read more

SSL handshake is a process where a client and server establish a secure connection by exchanging encryption keys and verifying identities.

• Client sends a request to the server to initiate the handshake

• Server responds with its digital certificate

• Client verifies the certificate and generates a pre-master secret

• Both parties exchange encrypted messages using the pre-master secret to establish a secure connection

Application override is a feature in network security that allows certain applications to bypass security policies.

• Application override allows specific applications to bypass firewall rules or other security measures.

• It is typically used for critical applications that may be blocked by default security settings.

• Administrators can configure application override rules to allow certain traffic to pass through the network ...read more

The session table typically stores information about active network connections and their associated details.

• Contains information such as source and destination IP addresses

• Stores port numbers being used in the connection

• Tracks the protocol being used (e.g. TCP, UDP)

• May include timestamps for when the connection was established and last active

HA3 belongs to HMAC (Hash-based Message Authentication Code) and is used for secure authentication and integrity verification.

• HA3 stands for Hash-based Message Authentication Code 3

• It is used in cryptographic hash functions for secure authentication and integrity verification

• HA3 is commonly used in network security protocols such as TLS (Transport Layer Security) and IPsec (Internet Protocol Security)

Check the system logs for cluster failure in Paloalto firewall.

• Check the system logs for any error messages related to cluster failure

• Look for logs indicating cluster synchronization issues

• Review logs for any hardware or software failures in the cluster

Heart Beat link is a feature in network security that ensures continuous communication between devices.

• Heart Beat link is a mechanism used to maintain a connection between two devices by sending periodic signals.

• It helps in detecting if a device is still active and reachable on the network.

• If the Heart Beat link fails, it can trigger alerts or actions to address the issue.

• Example: In a VPN connection, Heart Beat link c...read more

There are four types of logs in the monitor tab in Panorama.

• Traffic logs

• Threat logs

• URL logs

• Data logs

To configure a firewall from scratch, the first step is to define the security policy.

• Define the security policy based on the organization's requirements and compliance standards

• Identify the network topology and determine the zones that need to be protected

• Select the appropriate firewall hardware or software based on the requirements

• Configure the firewall rules to allow or deny traffic based on the security policy

• Test ...read more

Stateful means the system or device keeps track of the state of active connections and can differentiate between different connections.

• Stateful devices maintain information about the state of active connections

• They can differentiate between different connections based on various parameters

• Stateful firewalls keep track of the state of network connections to make decisions on allowing or blocking traffic

The phases of a VPN include initiation, negotiation, data transfer, and termination.

• Initiation phase involves establishing a connection between the client and server.

• Negotiation phase involves agreeing on encryption algorithms and keys.

• Data transfer phase is when actual data is transmitted securely.

• Termination phase involves closing the connection.

• Examples: IKEv2 VPN protocol follows these phases.

A firewall filters traffic based on predetermined rules, while a next generation firewall includes additional features like intrusion prevention and application awareness.

• Firewall filters traffic based on IP addresses and ports

• Next generation firewall includes intrusion prevention, application awareness, and deep packet inspection

• NGFW can identify and block advanced threats like malware and ransomware

• NGFW can provide m...read more