Cognizant Cyber Security Engineer Interview Questions and Answers

Stuck switching refers to a situation where a network switch is unable to forward traffic due to a malfunction or configuration issue.

• Stuck switching can occur when a switch's forwarding table becomes corrupted or when there is a hardware failure.

• It can also happen if there is a loop in the network causing broadcast storms.

• Troubleshooting stuck switching involves checking the switch's configuration, monitoring network ...read more

BGP path selection process determines the best path for routing based on various attributes.

• BGP selects the path with the highest weight attribute first

• If weights are the same, BGP looks at the local preference attribute

• Next, BGP considers the AS path length

• BGP then checks the origin code attribute

• After that, BGP looks at the MED (Multi-Exit Discriminator) attribute

• If all else is equal, BGP chooses the path with the lo...read more

A stub area is an OSPF area that does not contain external routes.

• Stub areas reduce the amount of routing information exchanged within an OSPF network.

• Stub areas use a default route to reach external networks.

• Stub areas are commonly used to reduce the size of the OSPF database and improve network performance.

STP stands for Spanning Tree Protocol, used in network environments to prevent loops and ensure redundant paths are utilized efficiently.

• STP is a network protocol used to prevent loops in Ethernet networks.

• It works by selecting a single path for data traffic while blocking redundant paths.

• STP elects a root bridge and calculates the shortest path to each network segment.

• If a link fails, STP recalculates the network topo...read more

VRRP stands for Virtual Router Redundancy Protocol, used to provide high availability for routers by creating a virtual IP address.

• VRRP allows multiple routers to work together in a group, with one router acting as the master and others as backups.

• If the master router fails, one of the backup routers takes over the virtual IP address to ensure continuous network connectivity.

• VRRP uses a priority value to determine whic...read more

VLANs are created to segment network traffic, improve network performance, enhance security, and simplify network management.

• Segment network traffic to improve performance and reduce congestion

• Enhance security by isolating sensitive data or devices

• Simplify network management by grouping devices logically

• Allow for easier troubleshooting and maintenance

• Enable better control over broadcast domains

• Example: Creating separat

Configuring FAILOVER via static Route involves setting up multiple routes with different priorities.

• Create multiple static routes with different next-hop IP addresses

• Assign different administrative distances to each static route

• Configure IP SLA to track the primary route and switch to the secondary route if the primary route fails

3 way hand shaking is a process in TCP/IP communication where three packets are exchanged to establish a connection.

• Three packets are involved: SYN, SYN-ACK, ACK

• SYN packet is sent by the client to the server to initiate the connection

• SYN-ACK packet is sent by the server to the client as a response

• ACK packet is sent by the client to the server to confirm the connection

The OSI Model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven layers.

• The OSI Model stands for Open Systems Interconnection Model.

• It helps in understanding how data is transferred between devices in a network.

• Each layer has specific functions and communicates with the adjacent layers.

• Examples of layers include Physical, Data Link, Network, Transport, Sessio

TCP is connection-oriented, reliable, and slower, while UDP is connectionless, unreliable, and faster.

• TCP is connection-oriented, meaning it establishes a connection before sending data, while UDP is connectionless.

• TCP is reliable as it ensures all data is received in order and without errors, while UDP does not guarantee delivery.

• TCP is slower due to the overhead of establishing and maintaining connections, while UDP ...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 a trusted internal network and untrusted external network

• Filters traffic based on rules set by the network administrator

• Can be hardware-based or software-based

• Examples include Cisco ASA, Palo Alto Networks, and pfSense

BGP routing tables store information about routes to different networks and the best path to reach them.

• BGP uses a path-vector routing protocol to determine the best path for a packet to reach its destination.

• BGP routing tables contain information about the network prefixes, the next hop to reach them, and the path attributes that determine the best path.

• BGP routers exchange routing information with their neighbors to ...read more

NAT is a technique used to map private IP addresses to public IP addresses. Port numbers are used to identify specific applications.

• NAT stands for Network Address Translation

• It is used to allow devices with private IP addresses to access the internet using a public IP address

• Port numbers are used to identify specific applications or services

• Common port numbers include 80 for HTTP, 443 for HTTPS, and 22 for SSH

Default single port range when neither port range in source NAT pools nor default port range are configured.

• When neither port range in source NAT pools nor default port range are configured, the default single port range is 1024 through 63,487.

• This range is used for outbound traffic initiated by the device.

• It is important to configure the port range to avoid conflicts with other devices on the network.

• For example, if m...read more

MSS in TCP refers to the maximum segment size, which is the largest amount of data that can be sent in a single TCP segment.

• MSS is negotiated during the TCP three-way handshake

• It is determined by the maximum transmission unit (MTU) of the network

• MSS can be adjusted by the sender or receiver using TCP options

• A smaller MSS can help prevent fragmentation and improve network performance

Packet drops can be caused by various factors. Troubleshooting involves identifying the root cause and implementing a solution.

• Check for network congestion or bandwidth limitations

• Verify if the packet is being dropped at the source or destination

• Inspect network devices for errors or misconfigurations

• Use packet capture tools to analyze the traffic

• Consider implementing Quality of Service (QoS) policies

• Update firmware or

To check port and duplex setting, MSS and MTU, and link utilization in network engineering.

• Use command 'show interface' to check port and duplex setting.

• Use command 'ping -f -l ' to check MTU.

• Use command 'netstat -s' to check MSS.

• Use command 'show interface' or 'show interfaces utilization' to check link utilization.