Basic CS [3i Infotech Placement]: Sample Questions 175 - 177 of 243

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Question 175

Basic CS

Write in Short

Short Answer▾

What is passive topology?


Understanding of Linear Bus
  • When the computers on the network simply listen and receive the signal, they are referred to as passive because they don՚t amplify the signal in any way.
  • Example for passive topology - linear bus.
  • Linear bus topology consists of a main run of cable with a terminator at each end.
  • All nodes are connected to the linear cable.
  • Ethernet and local talk network use a linear bus topology.

Question 176


Describe in Detail


Can you dynamically allocate arrays in a single call to malloc?


Understanding of Malloc Function
  • malloc can be used to allocate memory for single variable also,
  • p = (int ⚹) malloc (sizeo (int) ) ;
  • Allocates space for a single int, which can be accessed as ⚹ p.
  • Single variable allocations are just special case of array allocations.
  • Array with only one element.

Question 177

Basic CS

Describe in Detail


What are some of the routing protocols typically is use in a network.



  • Routing Information Protocol used on small or medium sized internal networks
  • Connected to the early Internet.
  • Capable of routing messages across networks up to a maximum of 15 hops.
  • Enabled routers to discover network by first sending a message requesting router tables from neighbouring devices.
  • Neighbour routers running RIP respond by sending the full routing tables back to the requestor the requestor follows an algorithm to merge all of these updates into its own table.


  • Open Shortest Path First was created to overcome limitations of RIP
    • The 15 hop count restriction
    • The inability to organize networks into a routing hierarchy, important for manageability and performance on large internal networks
    • The significant network traffic generated by repeatedly re-sending full router tables at scheduled intervals.
  • OSPF is an open public standard with widespread across many industry vendors.
  • It is the only link state routing protocol listed in this category.


  • Cisco developed Internet Gateway Routing Protocol as another alternative to RIP.
  • The newer Enhanced IGRP made.
  • EIGRP supports classless IP subnets and improves the efficiency of the routing algorithms compared to older IGRP.
  • It does not support routing hierarchies, like RIP.
  • Created as a proprietary protocol runnable only on Cisco family devices.
  • EIGRP was designed with the goals of easier configuration and better performance than OSPF.


  • Functions of The Intermediate System to Intermediate System protocol similarly to OSPF.
  • Remains in widespread use by service providers who benefitted from the protocol being more easily adaptable to their special environments.
  • Not run over Internet Protocol (IP) and uses its own addressing scheme.

BGP and EGP:

  • The Border Gateway Protocol is the Internet standard External Gateway Protocol.
  • Detects modifications to routing tables and selectively communicates those changes to other routers over TCP/IP.
  • Internet providers commonly use BGP to join their networks together.
  • Larger business use BGP to join together multiple of their internal networks.

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