Network Communication and Protocol Layers BDC Practice Questions (Page 1)

Questions 1–5

1. 1expert · hard

   A blockchain network is designed with a layered architecture. The network layer uses a gossip protocol, the consensus layer uses a BFT algorithm, and the application layer hosts smart contracts. A performance issue is traced to the network layer causing delays in block delivery. Which change would most directly address the issue without affecting the consensus or application layers?

   • AModify the BFT consensus algorithm to require fewer message rounds.
   • BOptimize the gossip protocol to reduce redundant message transmissions.
   • CIncrease the block size to reduce the number of blocks.
   • DRefactor the smart contract code to be more efficient.
   Reveal Solution Discussion Select an answer first
2. 2application · medium

   A blockchain developer is setting up a node for a public blockchain. They want to ensure the node can discover other peers without relying on a central server. Which mechanism should they use?

   • ADisable peer discovery and rely on manual connections.
   • BUse a decentralized peer discovery protocol such as Kademlia DHT.
   • CUse a single DNS seed that is maintained by the development team.
   • DHardcode a list of IP addresses of all nodes in the network.
   Reveal Solution Discussion Select an answer first
4. 3application · medium

   A blockchain network is experiencing delayed block propagation, causing forks and wasted mining effort. The network uses a simple flooding protocol. Which improvement would most directly reduce propagation delay?

   • AUse a gossip protocol with a well-connected topology and fast relay of new blocks.
   • BUse a centralized server to broadcast blocks instantly.
   • CIncrease the block size to include more transactions.
   • DReduce the number of peers per node to lower network traffic.
   Reveal Solution Discussion Select an answer first
5. 4expert · hard

   A blockchain network is experiencing inconsistent state across nodes due to a network partition. The consensus algorithm requires a quorum of nodes to agree. Which approach would best ensure consistency during a partition?

   • AIncrease the block size to reduce the number of blocks.
   • BAllow any node to continue producing blocks during a partition.
   • CUse a gossip protocol that ensures all nodes receive all messages.
   • DUse a consensus algorithm that requires a supermajority (e.g., 2/3) of nodes to agree, ensuring that only one partition can reach consensus.
   Reveal Solution Discussion Select an answer first
6. 5application · medium

   A blockchain architect is designing a new blockchain and wants to ensure that the network layer is independent from the consensus layer. Which design principle supports this?

   • AUse the same data structures for both layers.
   • BDefine clear interfaces between the network and consensus layers.
   • CHave the consensus layer directly control network connections.
   • DCombine the network and consensus layers into a single module.
   Reveal Solution Discussion Select an answer first