Routing & Switching (VLAN, DHCP, NAT) : MCQs & PYQs with Explanation

Option C

In Circuit Switching, a dedicated physical path (circuit) is created between the sender and receiver before communication starts. This path remains reserved for the entire duration of the call.

• Each connection gets its own separate path.
• The path cannot be used by anyone else until the communication is finished.
• This is why circuit switching is used in traditional telephone networks.

So, when multiple users communicate at the same time, each user gets a separate circuit.

Option C

In computer networks, routing protocols are used by routers to share information about available paths so data can reach its destination efficiently. These routing protocols are broadly classified into classful and classless types.

Classful routing protocols like RIPv1 and IGRP were introduced early in networking when IP addressing followed fixed class boundaries, Class A, B, and C networks. These protocols do not include subnet mask information in their routing updates. As a result, all subnets within the same major network must use the same subnet mask. This limitation makes them incompatible with Variable Length Subnet Masking (VLSM), where different subnets can have different mask lengths to optimize IP address usage.

In contrast, classless routing protocols like RIPv2, OSPF, and EIGRP, include the subnet mask information in every routing update. This allows routers to support VLSM and CIDR (Classless Inter-Domain Routing), providing better flexibility and efficient use of IP addresses.

Option A

Zeroconf (Zero Configuration) and Plug-and-Play mean that a device should automatically get network settings without manual configuration. The protocol that helps devices automatically get an IP address, subnet mask, and other settings is DHCP (Dynamic Host Configuration Protocol).

• It assigns IP addresses automatically.
• No manual setup is needed.

Option D

Routing Algorithms are used in computer networks to determine the best path for transferring data packets from source to destination. Routing algorithms are mainly divided into two categories:

• Adaptive Routing Algorithms.
• Non-Adaptive Routing Algorithms.

Adaptive Routing Algorithms are routing algorithms that make routing decisions based on current network conditions such as traffic load, congestion, delays, and changes in network topology. 
These algorithms dynamically update routing paths to select the most efficient route for data transmission.
A Non-Adaptive Algorithm does not change its routing decisions according to current network traffic, congestion, or topology changes. The routes are fixed and predefined.

Option D

OSPF (Open Shortest Path First) is a link-state Interior Gateway Protocol (IGP) used for routing within a single Autonomous System (AS), such as an organization or a campus network. It uses the link-state routing algorithm.

Option C

In computer networks, flooding is a routing technique in which an incoming packet is sent through every outgoing path except the path from which the packet arrived.
In flooding, routers forward copies of the packet to all neighboring nodes, increasing the chances that the packet reaches the destination.
Flooding is mainly used in broadcasting, route discovery, and emergency routing situations.