Barclays Global Service Centre System Engineer Interview Questions and Answers

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

• Firewall acts as a barrier between a trusted, secure internal network and another network, such as the Internet.

• It examines each packet of data that passes through it and determines whether to allow or block the traffic based on the set of rules.

• Firewalls can be hardware or softwa...read more

BGP attributes are used to determine the best path for routing traffic between networks.

• BGP attributes include: AS Path, Next Hop, Local Preference, MED, Origin, and Community

• AS Path is a list of autonomous systems that the route has passed through

• Next Hop is the IP address of the next router on the path

• Local Preference is used to indicate the preferred path for outbound traffic

• MED (Multi-Exit Discriminator) is used to...read more

VPN stands for Virtual Private Network. It allows secure remote access to a private network over the internet.

• VPN creates a secure and encrypted connection between the user's device and the private network.

• It masks the user's IP address and location, providing anonymity and privacy.

• VPN uses different protocols such as PPTP, L2TP, IPSec, and OpenVPN.

• It can be used to access geographically restricted content, bypass cens...read more

Routing protocols are used to determine the best path for data to travel in a network.

• Distance Vector protocols: RIP, IGRP, EIGRP

• Link State protocols: OSPF, IS-IS

• Hybrid protocols: BGP

• Path Vector protocols: BGP

• IGP vs EGP

VTP stands for VLAN Trunking Protocol, used to manage VLANs in a switched network.

• VTP is a Cisco proprietary protocol.

• It allows for easy VLAN management by propagating VLAN information across the network.

• VTP operates in three modes: server, client, and transparent.

• Server mode allows for VLAN creation, deletion, and modification.

• Client mode receives and stores VLAN information.

• Transparent mode forwards VTP messages but ...read more

Routers connect networks while firewalls protect networks from unauthorized access.

• Routers direct traffic between networks while firewalls filter traffic based on predefined rules.

• Routers operate at layer 3 of the OSI model while firewalls operate at layer 4 or higher.

• Examples of routers include Cisco routers, while examples of firewalls include Fortinet firewalls.

• Routers can be used to segment networks while firewalls...read more

The largest area in a histogram refers to the rectangle with the maximum area that can be formed within the histogram.

• To find the largest area in a histogram, we can use the concept of a stack.

• We iterate through each bar in the histogram and maintain a stack of bars in non-decreasing order of their heights.

• If the current bar's height is greater than the height of the bar at the top of the stack, we push the current bar...read more