Cisco CCNA Basic Switching Concepts 4 — Questions and Answers
Question 1: Which frame type does a switch forward only out the single port associated with the destination MAC address?
- Broadcast
- Unknown unicast
- Known unicast (Correct answer)
- Multicast
Correct answer: Known unicast
When the destination MAC is found in the MAC address table (known unicast), the switch forwards the frame only to the specific port associated with that address.
Question 2: What is the collision domain boundary on a switch?
- Each VLAN is one collision domain
- The entire switch is one collision domain
- Each switch port is its own collision domain (Correct answer)
- Each broadcast domain is one collision domain
Correct answer: Each switch port is its own collision domain
Each port on a switch is its own collision domain because switches segment collisions at the port level.
Question 3: A Cisco switch port is configured with 'spanning-tree portfast'. What is the effect?
- The port immediately transitions to Forwarding state, bypassing Listening and Learning (Correct answer)
- The port is excluded from STP entirely and loops can form
- The port speed is increased to forward faster
- The port blocks all multicast traffic
Correct answer: The port immediately transitions to Forwarding state, bypassing Listening and Learning
PortFast causes a port to skip the STP Listening and Learning states and immediately enter Forwarding, reducing connection time for end devices.
Question 4: Which type of address is FF:FF:FF:FF:FF:FF?
- Unicast MAC address
- Multicast MAC address
- Broadcast MAC address (Correct answer)
- Anycast MAC address
Correct answer: Broadcast MAC address
FF:FF:FF:FF:FF:FF is the Layer 2 broadcast address; frames with this destination are sent to all devices in the broadcast domain.
Question 5: What is the maximum number of MAC addresses that can be configured with port security on a single Cisco switch port by default?
- 1 (Correct answer)
- 2
- 8
- 128
Correct answer: 1
The default maximum number of secure MAC addresses per port with port security enabled is 1.
Question 6: When port security detects a violation in 'protect' mode, what happens?
- The port shuts down (err-disabled)
- Frames from violating MACs are dropped but no notification is sent (Correct answer)
- An SNMP trap is sent and the port stays up
- The switch sends a syslog message and drops one frame
Correct answer: Frames from violating MACs are dropped but no notification is sent
In protect mode, frames from unauthorized MAC addresses are silently dropped without generating any log messages or SNMP traps.
Question 7: What Layer 2 device forwards frames based on MAC addresses and creates separate collision domains per port?
- Hub
- Router
- Switch (Correct answer)
- Repeater
Correct answer: Switch
A switch operates at Layer 2 and makes forwarding decisions based on MAC addresses, with each port being its own collision domain.
Cisco CCNA Basic Switching Concepts 4
Which frame type does a switch forward only out the single port associated with the destination MAC address?