CCNA Tutorial 1.4 – Interface and Cable Issues
- Collisions
- Errors (CRC, Runts, Giants)
- Duplex mismatch
- Speed issues
Quiz
Multiple Choice (20 questions)
- Which device is most associated with collisions in Ethernet networks?
- A) Switch
- B) Hub
- C) Router
- D) Firewall
- What does a late collision usually indicate?
- A) Duplex mismatch
- B) Excessive cable length
- C) Power over Ethernet failure
- D) Wrong IP address
- Which of the following is a symptom of a duplex mismatch?
- A) High number of CRC errors
- B) Frequent collisions
- C) Slow network performance despite good cabling
- D) All of the above
- If a switch port is set to full-duplex and the connected device is half-duplex, what issue occurs?
- A) Speed mismatch
- B) Duplex mismatch
- C) Broadcast storm
- D) Interface shutdown
- Which type of error occurs when a frame is smaller than the minimum Ethernet size (64 bytes)?
- A) Giant
- B) Runt
- C) Late collision
- D) CRC error
- Which error occurs when a frame is larger than the maximum Ethernet size (1518 bytes without VLAN tagging)?
- A) CRC error
- B) Runt
- C) Giant
- D) Alignment error
- Which error indicates that the data inside the frame is corrupted?
- A) CRC error
- B) Collision
- C) Runt
- D) Giant
- Which condition typically causes CRC errors?
- A) Duplex mismatch
- B) Damaged cables or interference
- C) Oversized frames
- D) Hub congestion
- A speed mismatch occurs when:
- A) Both sides use the same speed
- B) One side is configured for 100 Mbps and the other for 1 Gbps
- C) The NIC is disabled
- D) The IP address is wrong
- Which show command on a Cisco device is commonly used to detect interface errors?
- A) show ip route
- B) show running-config
- C) show interfaces
- D) show mac address-table
- Which cable issue can result from exceeding the maximum length for copper Ethernet?
- A) Duplex mismatch
- B) Collisions
- C) Late collisions and CRC errors
- D) VLAN mismatch
- Which symptom is most common with a bad Ethernet cable?
- A) Giants
- B) High CRC error count
- C) IP conflicts
- D) Loop detection
- What happens if auto-negotiation fails on both sides of an Ethernet link?
- A) Both default to full duplex
- B) Both default to half duplex
- C) Link operates normally
- D) Interface shuts down
- Which of the following is most likely if you see input errors on a Cisco interface?
- A) Cabling issue or interference
- B) Incorrect IP address
- C) Wrong VLAN assignment
- D) Loopback testing
- Alignment errors typically occur when:
- A) Frames do not end on an 8-bit boundary
- B) Oversized frames are received
- C) VLAN tags are mismatched
- D) Routing tables are incorrect
- If one device is set manually to 100 Mbps and the other is set to auto-negotiate, what is likely?
- A) Speed mismatch only
- B) Duplex mismatch
- C) No connectivity at all
- D) Correct configuration
- Which of the following is NOT a common interface issue?
- A) Collisions
- B) CRC errors
- C) Speed mismatch
- D) DHCP scope exhaustion
- Which error is often the result of electromagnetic interference (EMI)?
- A) Runt
- B) Giant
- C) CRC error
- D) Late collision
- If a cable is wired incorrectly (e.g., wrong pinout), what will happen?
- A) Broadcast storm
- B) No link or high error rate
- C) VLAN hopping
- D) Loop detection
- Which condition best explains slow throughput despite no packet drops at Layer 3?
- A) Duplex mismatch at Layer 2
- B) Routing loop
- C) Firewall ACLs
- D) MTU mismatch
Fill in the Blank (5 questions)
- A frame smaller than 64 bytes is called a __________.
- A frame larger than the maximum allowed size is called a __________.
- A corrupted frame detected at the data link layer produces a __________ error.
- A mismatch between full-duplex and half-duplex settings is called a __________ mismatch.
- Exceeding the 100-meter cable limit on copper Ethernet often results in __________ collisions.
Answer Key
- B) Hub
- B) Excessive cable length
- D) All of the above
- B) Duplex mismatch
- B) Runt
- C) Giant
- A) CRC error
- B) Damaged cables or interference
- B) One side is configured for 100 Mbps and the other for 1 Gbps
- C) show interfaces
- C) Late collisions and CRC errors
- B) High CRC error count
- B) Both default to half duplex
- A) Cabling issue or interference
- A) Frames do not end on an 8-bit boundary
- B) Duplex mismatch
- D) DHCP scope exhaustion
- C) CRC error
- B) No link or high error rate
- A) Duplex mismatch at Layer 2
- Runt
- Giant
- CRC
- Duplex
- Late