ICND1 LAN Switching Technologies 2 — Questions and Answers
Question 1: Which STP port state forwards frames and learns MAC addresses?
- Blocking
- Listening
- Learning
- Forwarding (Correct answer)
Correct answer: Forwarding
Only the Forwarding state both learns MAC addresses and forwards data frames.
Question 2: What is the default bridge priority value used in Spanning Tree Protocol?
- 4096
- 8192
- 32768 (Correct answer)
- 65535
Correct answer: 32768
The default STP bridge priority is 32768 on all Cisco switches unless manually changed.
Question 3: Which VLAN trunking protocol mode will only forward VLANs that are created locally on the switch?
- VTP Server
- VTP Client
- VTP Transparent (Correct answer)
- VTP Off
Correct answer: VTP Transparent
VTP Transparent mode does not participate in VTP domain synchronization and only uses locally configured VLANs.
Question 4: What command correctly assigns an access port to VLAN 20 on a Cisco switch?
- switchport vlan 20
- switchport access vlan 20 (Correct answer)
- vlan access 20
- switchport mode vlan 20
Correct answer: switchport access vlan 20
The command 'switchport access vlan 20' assigns the interface to VLAN 20 as an access port.
Question 5: Which field in an 802.1Q frame carries the VLAN identifier?
- Preamble
- EtherType
- VLAN ID (VID) within the 4-byte tag (Correct answer)
- FCS
Correct answer: VLAN ID (VID) within the 4-byte tag
The 12-bit VID field inside the 4-byte 802.1Q tag identifies the VLAN the frame belongs to.
Question 6: A switch receives a frame destined for a MAC address not in its CAM table. What does it do?
- Drops the frame
- Sends an ARP request
- Floods the frame out all ports except the receiving port (Correct answer)
- Sends the frame to the default gateway
Correct answer: Floods the frame out all ports except the receiving port
When a destination MAC is unknown, the switch floods the frame out every port in the VLAN except the ingress port.
Question 7: Which STP variant is defined by IEEE 802.1w and provides faster convergence than classic STP?
- PVST+
- MSTP
- RSTP (Correct answer)
- CST
Correct answer: RSTP
IEEE 802.1w defines Rapid Spanning Tree Protocol (RSTP), which dramatically reduces convergence time.
ICND1 LAN Switching Technologies 2
Which STP port state forwards frames and learns MAC addresses?