nokia 4A0-105 Exam Questions
Questions for the 4A0-105 were updated on : Nov 21 ,2025
Page 1 out of 11. Viewing questions 1-15 out of 156
Question 1
The service mtu of a VPLS is set to 9100. What is the recommended MTU value that can be set for the
access port assuming dot1q encapsulation?
- A. 9100
- B. 9104
- C. 9108
- D. 9122
- E. 9126
Answer:
B
Question 2
What action will be taken when an MPLS router receives a frame with a label that does not exist in
the LFIB?
- A. The frame will be flooded.
- B. The frame will be discarded.
- C. The frame will be fragmented.
Answer:
B
Question 3
In IEEE 802.1ag, which two key functions are configured on bridge ports (SAPs and SDPs) to support
CFM messages? (Choose 2)
- A. MEP
- B. MAP
- C. MIP
- D. MUP
Answer:
AC
Question 4
How does PBB forward broadcast, unknown-unicast and multicast traffic from a B-VPLS to an l-VPLS?
- A. The receiving PE checks the l-TAG in the l-SID to determine if there is a local l-VPLS on the node.
- B. The receiving PE checks the l-SID in the l-TAG to determine if there is a local l-VPLS on the node.
- C. The receiving PE checks the service label in the mpls header to determine if there is a local l-VPLS on the node.
- D. The receiving PE checks the multicast B-DA to see if an l-SID has been mapped to the B-DA that matches a local l-VPLS on the node.
Answer:
D
Question 5
Which of the following is a true statement?
- A. The lower the age-time, the greater the amount of flooding
- B. The higher the age-time, the greater the amount of flooding.
- C. The lower the age-time, the lower the amount of flooding.
- D. There is no relationship between the age-time and the amount of flooding.
Answer:
A
Question 6
An MC-LAG is configured with default parameters. When a failed interface recovers, the active link
reverts to the restored interface.
- A. TRUE
- B. FALSE
Answer:
B
Question 7
In RSTP, how is the root bridge selected?
- A. The switch with the highest bridge-id is selected as root.
- B. The switch with the lowest bridge-id is selected as root.
- C. The switch with the highest MAC address is selected as root
- D. The switch with the lowest MAC address is selected as root.
Answer:
B
Question 8
Which of the following needs to be considered when designing Ethernet networks with redundancy?
- A. Processing the TTL takes extra time.
- B. MAC learning rate is doubled.
- C. FDB size is doubled.
- D. Requires a protocol to remove loops.
Answer:
D
Question 9
After the "disable-learning" command has been executed at the VPLS level, a new client device
originates a frame. What is the result?
- A. If the MAC address of this new client device does not reach the upper limit of the configured total number of MAC addresses allowed in the VPLS forwarding database, then the new MAC address will be stored.
- B. The new source MAC addresses will not be entered in the VPLS service forwarding database.
- C. New local source MAC addresses will not be entered in the VPLS service forwarding database, but new remote MAC addresses would continue to be entered.
- D. New remote source MAC addresses will not be entered in the VPLS services forwarding database, but new local MAC addresses would continue to be entered.
Answer:
B
Question 10
Which of the following best describes the difference between VPWS and VPLS?
- A. Unlike VPLS. VPWS appears as a multi-hop network to the customers.
- B. Unlike VPLS, VPWS allows CEs that are member of the same service instance to communicate with each other as if they are connected via a bridged LAN.
- C. Unlike VPWS, VPLS allows customers to view the network as a routed network.
- D. Unlike VPWS, VPLS is a service where customer MAC addresses are learned.
Answer:
D
Question 11
The following question relates to this command syntax: "config>service# vpls 9000 customer 6
create". Which of the following statements are correct? (Choose 2)
- A. The customer-id in this command is 9000.
- B. The service-id in this command is 9000.
- C. This value 9000 should be unique across the network as a best practice.
- D. The vc-id will be 6 for the service by default.
- E. The egress vc-label will be 9000.
Answer:
BC
Question 12
What function in IEEE 802.1 ah helps to limit the amount of MAC addresses learned in the core?
- A. I-VPLS is configured in the core of the network with an l-MAC address. This l-MAC address is the only MAC learned in the core
- B. The B-VPLS and l-VPLS are configured in the edge. The B-VPLS is configured with a Backbone MAC and is the only MAC learned in the core
- C. Each SDP is configured with a Backbone MAC to hide customer MAC addresses in the core
- D. Each SAP is associated with a common l-MAC to hide customer MAC addresses in the core
Answer:
B
Question 13
What is PBB also known as?
- A. H-VPLS
- B. IEEE 802.lag
- C. MAC aggregation
- D. MAC-in-MAC
Answer:
D
Question 14
Click on the exhibit below.
Based on the following configuration which VLANs will be managed by the management VPLS?
- A. VLANs 1-4094
- B. VLAN 0
- C. There is not enough information provided
- D. None, this is an invalid configuration
Answer:
A
Question 15
Click on the exhibit below.
In the diagram below, SAP 1 is put into the blocking state as a result of the spanning tree protocol.
What will occur in the VPLS instance if SAP 2 goes down and SAP 1 transitions to the forwarding
state? Select the most accurate statement.
- A. A Spanning Tree BPDU will be sent across the mesh flushing the FDB table in all devices participating in the VPLS instance.
- B. Stale information will be used within the VPLS instance to forward traffic until the FDB ages out.
- C. An LDP control message will be sent to all devices in the mesh participating in the VPLS instance. Only MAC addresses associated with the PE that the failure occurred on will be flushed.
- D. An LDP control message will be sent to all devices in the mesh participating in the VPLS instance. The entire FDB in the VPLS instance will be flushed.
Answer:
D