10+ Network Security Interview Questions and Answers

The transport layer is necessary for communication in computer networks to ensure reliable data delivery and manage connections.

• The transport layer is responsible for end-to-end communication between devices in a network.

• It provides error-checking mechanisms to ensure data integrity during transmission.

• Transport layer protocols like TCP establish connections, manage data flow, and handle congestion control.

• UDP, another transport layer protocol, is used for applications where ...read more

The task is to return all permutations of a given string in lexicographically increasing order.

• Use backtracking to generate all permutations of the string.

• Sort the permutations to get them in lexicographically increasing order.

• Ensure the string contains unique characters to avoid duplicate permutations.

Check if a given string is a palindrome considering only alphanumeric characters.

• Remove non-alphanumeric characters from the input string.

• Compare characters from start and end of the string to check for palindrome.

• Return 'true' if the string is a palindrome, 'false' otherwise.

MAC Address is a hardware address assigned to network devices, while IP Address is a logical address used for communication between devices.

• MAC Address is a unique identifier assigned to network interfaces for communications on the physical network.

• IP Address is a logical address used for identifying devices on a network and routing data packets.

• MAC Address is fixed and assigned by the manufacturer, while IP Address can be dynamic and assigned by a network administrator.

• Examp...read more

A subnet mask is a 32-bit number used to divide an IP address into network and host portions.

• It is used in conjunction with an IP address to determine which part of the address is the network ID and which part is the host ID.

• Subnet masks consist of a series of 1s followed by a series of 0s.

• For example, a subnet mask of 255.255.255.0 means the first 24 bits are for the network and the last 8 bits are for hosts.

The interview covered topics such as IP SLA, stateless and stateful firewalls, BGP attributes and best path selection, and VDOM in Fortinet Firewall.

• IP SLA is a Cisco technology that measures network performance and availability.

• Stateless firewalls filter traffic based on source and destination IP addresses, ports, and protocols, while stateful firewalls keep track of the state of network connections.

• BGP attributes are used to determine the best path for routing traffic betwe...read more

VLANs are needed to logically segment a network, improve security, optimize network performance, and simplify network management.

• VLANs help in isolating network traffic, reducing broadcast domains, and enhancing network security.

• They allow for better network performance by segmenting traffic and prioritizing certain types of data.

• VLANs simplify network management by grouping devices based on function or department.

• For example, a company can create separate VLANs for finance, ...read more

A switch in computer networking is a device that connects devices within a local area network (LAN) and forwards data packets between them.

• Switch operates at the data link layer of the OSI model

• It uses MAC addresses to forward data to the correct destination

• Switches increase network performance by reducing collisions and segmenting traffic

• Examples of switches include Cisco Catalyst series, Netgear ProSAFE switches

Prevent malware by using antivirus software, keeping software updated, avoiding suspicious links and downloads, and practicing safe browsing habits.

• Install and regularly update antivirus software

• Keep all software and operating systems up to date

• Avoid clicking on suspicious links or downloading attachments from unknown sources

• Practice safe browsing habits, such as not visiting untrustworthy websites or clicking on pop-up ads

• Use a firewall to block unauthorized access to your d...read more

The Data Link Layer is the second layer of the OSI model responsible for node-to-node communication within a network.

• Responsible for framing, addressing, and error detection

• Controls access to the physical medium

• Examples include Ethernet, Wi-Fi, and PPP protocols

BGP stands for Border Gateway Protocol, a routing protocol used to exchange routing information between different networks on the internet.

• BGP is used to make routing decisions based on network policies, path preferences, and network reachability.

• It is commonly used by Internet Service Providers (ISPs) to connect their networks and exchange routing information.

• BGP operates on the application layer of the OSI model and uses TCP port 179 for communication.

• An example of BGP in a...read more

OSPF (Open Shortest Path First) is a routing protocol used to determine the best path for data packets in a network.

• OSPF is a link-state routing protocol

• It uses Dijkstra's algorithm to calculate the shortest path

• OSPF routers exchange link-state advertisements (LSAs) to build a topology database

• It supports multiple areas for scalability

• OSPF is commonly used in large enterprise networks and ISPs

Honeypots are used to detect and analyze cyber attacks by luring attackers into a trap system.

• Honeypots are decoy systems designed to attract attackers.

• They can be used to gather information about attackers' tactics and techniques.

• Honeypots can also be used to divert attackers away from real systems.

• They can be deployed in different ways, such as high-interaction or low-interaction honeypots.

• Examples of honeypots include Honeyd, KFSensor, and Dionaea.