Practice Test GeeksCBDH - Certified Blockchain Developer Hyperledger Practice Test
← All CBDH Flashcard Decks

Troubleshooting & Problem Resolution Flashcards

7 cards from real CBDH practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Troubleshooting & Problem Resolution flashcards as text

  1. fabric-ca-client enroll returns 'Authentication failure'. What is the most probable reason?

    Answer: The enrollment ID or secret is wrong, or the identity was never registered

    Enrollment authenticates with the ID and secret created at registration, so a mismatch fails authentication.

  2. Cross-organization service discovery returns no peers for Org2 even though both orgs joined the channel. Which configuration is probably missing?

    Answer: Anchor peer definitions for the organizations

    Anchor peers let gossip and discovery locate peers across organizations.

  3. An application throws 'identity not found in wallet' when connecting through the Gateway. What is the correct fix?

    Answer: Enroll or import the user identity into the wallet before connecting

    The Gateway needs the identity stored in the wallet under the label used in the connect options.

  4. A client running outside Docker gets ECONNREFUSED or DNS errors when connecting to peer0.org1.example.com. What is a sound resolution?

    Answer: Map hostnames to the exposed ports (for example in /etc/hosts or a localhost override) and match the TLS name

    Container hostnames are not resolvable from the host, so the client needs resolvable names that still match the TLS certificate.

  5. The error 'creator org unknown, creator is malformed' appears when the client's wallet identity has MSP ID Org1 but the channel defines Org1MSP. What is the issue?

    Answer: The identity's MSP ID does not match the MSP ID in the channel configuration

    Identities are validated against the MSP ID defined in the channel config, and the strings must match exactly.

  6. A block event listener misses blocks committed while the application was offline. What is the recommended approach?

    Answer: Use a checkpointer or store the last processed block number and replay from it on restart

    Persisting the last processed block allows the listener to resume from the next block after a restart.

  7. Peers within one organization do not receive blocks via gossip, and only the leader pulls from the orderer. Which setting is most likely misconfigured?

    Answer: CORE_PEER_GOSSIP_BOOTSTRAP and the peer's external endpoint

    Gossip needs correct bootstrap and external endpoints so peers can discover and connect to each other.

How this page was made: written with AI tools and published by Nathan Beja, founder of Practice Test Geeks, who is responsible for its content. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy

Sources & references

Exam facts on this page (fees, format, dates, passing scores) are checked against these official sources; the date is our last check. Editorial policy

  1. blockchaintrainingalliance.com — Test delivery, passing score, score release, test dates, fees, exam format, time limit · verified Oct 2026