Top 100 Network Security Interview Questions and Answers

Firewall is a network security system that monitors and controls incoming and outgoing network traffic.

• Firewall acts as a barrier between a trusted internal network and untrusted external network

• It can be used to block unauthorized access to a networ...read more

Application level firewall filters traffic based on application layer protocols while stateful firewall filters based on connection state.

• Application level firewall operates at layer 7 of OSI model while stateful firewall operates at layer 4.

• Applicat...read more

IDS detects and alerts about potential threats, while IPS detects and prevents them.

• IDS stands for Intrusion Detection System

• IPS stands for Intrusion Prevention System

• IDS monitors network traffic and alerts about potential threats

• IPS actively blocks ...read more

IDS and IPS are security systems that monitor network traffic for malicious activity and prevent attacks.

• IDS (Intrusion Detection System) detects and alerts about potential attacks by analyzing network traffic and comparing it to known attack pattern...read more

It is not possible to stop man-in-the-middle attacks over an insecure communication line without encryption.

• Encryption is the most effective way to prevent man-in-the-middle attacks.

• Without encryption, an attacker can intercept and modify the communi...read more

NACL and security groups are both AWS network security features, but NACL operates at the subnet level while security groups operate at the instance level.

• NACL is stateless while security groups are stateful

• NACL can allow or deny traffic based on IP ...read more

The objective of network security is to protect computer networks and data from unauthorized access, attacks, and misuse.

• Preventing unauthorized access to network resources

• Protecting sensitive data from being intercepted or modified

• Detecting and miti...read more

DDoS stands for Distributed Denial of Service, a type of cyber attack that floods a network or website with traffic to make it unavailable.

• DDoS attacks are carried out by multiple compromised systems, often called a botnet.

• The goal of a DDoS attack i...read more

2 way SSL is needed for mutual authentication between client and server.

• 2 way SSL ensures that both client and server are authenticated

• It provides an extra layer of security by verifying the identity of both parties

• It is commonly used in financial tr...read more

Various types of packets can be used for DOS attacks, including SYN floods, UDP floods, and ICMP floods.

• SYN floods involve sending a large number of SYN packets to overwhelm the target server's resources.

• UDP floods involve sending a large number of U...read more

Yes, there is a breach in the network.

• Unusual network traffic patterns

• Unauthorized access to sensitive data

• Unexpected system behavior or performance issues

• Logs indicating suspicious activities

• Security alerts or notifications

To strengthen network security, I would implement strong encryption, regularly update software, conduct regular security audits, and educate users on best practices.

• Implement strong encryption protocols such as SSL/TLS to protect data in transit

• Regul...read more

I have worked on various network security devices including firewalls, intrusion detection/prevention systems, and VPNs.

• Firewalls such as Cisco ASA and Fortinet FortiGate

• Intrusion detection/prevention systems such as Snort and Cisco Firepower

• VPNs suc...read more

To set firewall outside policy, you need to adjust the rules and configurations to allow or block specific traffic.

• Review the current firewall policy to understand what is allowed and what is blocked

• Identify the specific traffic or IP addresses that ...read more

TLS handshake is the process of establishing a secure connection between a client and a server.

• TLS handshake is initiated by the client and involves a series of steps to negotiate encryption parameters and exchange cryptographic keys.

• It ensures the a...read more

Protecting network and data involves implementing security measures to prevent unauthorized access and data breaches.

• Implement strong passwords and two-factor authentication

• Use firewalls and antivirus software

• Regularly update software and security pa...read more

Security tools can be installed using package managers or manually downloading and installing them.

• Use package managers like apt-get, yum, or pacman to install security tools

• Manually download and install security tools from their official websites

• Reg...read more

SSL certificate encrypts data transmitted between a server and a client to ensure secure communication.

• SSL certificate contains public key, private key, and information about the certificate holder.

• When a client connects to a server, the server sends...read more

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

• Acts as a barrier between internal network and external networks

• Filters incoming and outgoing traffic based...read more

Network VAPT is the process of assessing the security of a network by identifying vulnerabilities and testing for potential exploits.

• 1. Conducting a thorough assessment of the network infrastructure to identify potential vulnerabilities.

• 2. Performing...read more

SSL VPN handshake establishes a secure connection between client and server using encryption and authentication protocols.

• 1. Client Hello: The client sends a message to the server with supported SSL versions and cipher suites.

• 2. Server Hello: The ser...read more

Port-based security involves controlling access to network resources based on the physical port of the device.

• Port security can be implemented by limiting the number of MAC addresses that can be learned on a port.

• It can also involve configuring the p...read more

To ensure a server is secure, one must implement various security measures such as firewalls, encryption, regular updates, access control, and monitoring.

• Implement firewalls to control incoming and outgoing traffic

• Use encryption to protect data in tr...read more

Firewall policy determines what traffic is allowed or blocked based on predefined rules.

• Firewall policy is a set of rules that determine what traffic is allowed or blocked

• Rules can be based on source/destination IP, port, protocol, etc.

• Firewall can b...read more

Network penetration testing is the process of identifying vulnerabilities in a network and exploiting them to gain unauthorized access.

• It involves simulating an attack on a network to identify security weaknesses

• It can be done using automated tools o...read more

Isolate infected mail server, scan for virus, remove virus, restore from backup if necessary.

• Isolate infected mail server from network to prevent spread of virus

• Scan mail server with antivirus software to detect and remove virus

• Restore mail server fr...read more

SSL and TLS are both cryptographic protocols used to secure internet communications.

• SSL stands for Secure Sockets Layer and is an older protocol that has been largely replaced by TLS.

• TLS stands for Transport Layer Security and is the successor to SSL...read more