NTT DATA, Inc. Network Security Engineer Interview Questions and Answers

I am a dedicated and experienced network engineer with a strong background in designing, implementing, and maintaining network infrastructure.

• Over 5 years of experience in network engineering

• Proficient in configuring and troubleshooting network devices such as routers, switches, and firewalls

• Skilled in network design and implementation, including VLANs, VPNs, and routing protocols

• Certified in Cisco CCNA and CCNP

• Strong

DNS is a system that translates domain names into IP addresses. DHCP is a protocol for assigning IP addresses. IP address is a unique identifier for devices. RJ-45 is a type of connector used for Ethernet cables.

• DNS translates domain names (e.g., www.example.com) into IP addresses (e.g., 192.168.1.1).

• DHCP is a protocol that automatically assigns IP addresses to devices on a network.

• An IP address is a numerical label as...read more

The show interface command displays the status and statistics of a network interface.

• Displays the interface type, member, module, and number

• Shows the current status of the interface (up or down)

• Displays the number of packets transmitted and received

• Shows the number of errors and discards

• Displays the speed and duplex settings of the interface

Access is a port that allows a single VLAN while trunk is a port that allows multiple VLANs.

• Access ports are used to connect end devices like computers, printers, etc. to the network.

• Trunk ports are used to connect switches to each other and carry traffic for multiple VLANs.

• Access ports are assigned to a single VLAN while trunk ports can carry traffic for multiple VLANs.

• Access ports do not tag frames while trunk ports ...read more

LAN is a local area network that connects devices within a limited area, while WAN is a wide area network that connects devices over a large geographical area.

• LAN is typically used in homes, offices, or schools, while WAN is used to connect different LANs across cities, countries, or even continents.

• LAN has a higher data transfer rate and lower latency compared to WAN.

• Examples of LAN technologies include Ethernet, Wi-F...read more

To convert access into trunk, we need to configure the switch port as a trunk port.

• Configure the switch port as a trunk port using the 'switchport mode trunk' command.

• Verify the trunk configuration using the 'show interfaces trunk' command.

• Ensure that the VLANs allowed on the trunk are configured using the 'switchport trunk allowed vlan' command.

• Ensure that the native VLAN is configured using the 'switchport trunk nati

Load balancer distributes incoming network traffic across multiple servers to improve performance and availability.

• Load balancer acts as a reverse proxy server

• It distributes traffic based on various algorithms such as round-robin, least connections, IP hash, etc.

• It monitors server health and redirects traffic to healthy servers

• It can be hardware-based or software-based

• Examples of load balancers include F5, HAProxy, Ngi

Trunk is used to carry multiple VLANs between switches, while access is used to connect end devices to the network.

• Trunk is used to connect switches together and carry multiple VLANs

• Access is used to connect end devices like computers, printers, etc. to the network

• Trunk ports are configured with VLAN tagging, while access ports are not

• Examples of trunk ports are inter-switch links, while examples of access ports are po

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 port to only allow traffic from specific VLANs.

• Port security can be used to prevent unauthorized access to the network by limiting the devices that can connect to it.

• It can ...read more

VLAN stands for Virtual Local Area Network. It is a logical grouping of devices on a network based on function, department or application.

• VLANs allow for better network management and security by separating traffic into different broadcast domains.

• Devices in different VLANs cannot communicate with each other without a router or layer 3 switch.

• VLANs can be configured based on port, MAC address or protocol.

• Example: VLAN ...read more

BGP stands for Border Gateway Protocol. It is a routing protocol used to exchange routing information between different networks.

• BGP is used in large-scale networks such as the internet.

• It is a path-vector protocol that selects the best path for data to travel between networks.

• BGP uses TCP port 179 for communication.

• It is used to connect different autonomous systems (AS) together.

• BGP is used to prevent routing loops an...read more

The subnet mask for CIDR /29 is 255.255.255.248.

• CIDR /29 means 29 bits are used for the network portion and 3 bits for the host portion.

• To calculate the subnet mask, convert the 29 network bits to 1s and add 3 0s for the host bits.

• The result is 255.255.255.248 in dotted decimal notation.

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

• OSPF is a link-state protocol that uses Dijkstra's algorithm to calculate the shortest path between two points.

• It is used in large enterprise networks and is designed to scale well.

• OSPF routers exchange information about their connected networks and use this information to build a topology map of the ne...read more