nokia 4A0-115 Exam Questions
Questions for the 4A0-115 were updated on : Nov 21 ,2025
Page 1 out of 3. Viewing questions 1-15 out of 40
Question 1
In the exhibit, the EVPN-IRB is using the interface-ful unnumbered model and is fully operational.
Which of the following statements is FALSE?
- A. An MP-BGP session that supports the advertisement of VPN-IPv4 routes is established between PE3 and PE4.
- B. An MP-BGP session that supports the advertisement of EVPN routes is established between PEI and PE2.
- C. On PE3, the routing table for VPRN 15 contains an entry for 10.10.1.0/24. This entry is resolved to MAC-OI as an overlay index.
- D. On PE3, the routing table for VPRN 15 contains an entry for 10.10.4.0/24. This entry is resolved using a transport tunnel towards PE
Answer:
C
Explanation:
On PE3, the routing table for VPRN 15 does not contain an entry for 10.10.1.0/24.
This entry is not
needed because Host 1 is in the same subnet as the SBD IRB interface on PE3, and PE3 can reach
Host 1 using its MAC address2
.
Verified Reference:
Nokia Ethernet Virtual Private Network Services Course | Nokia
Question 2
In the exhibit, the EVPN-IRB is configured to use the interface-ful unnumbered model. Which of the
following statements regarding the route advertisement is FALSE?
- A. PEI advertises an EVPN IP-Prefix route for prefix 10.10.1.0/24 to PE3. The BGP update includes MAC-OI as on overlay index.
- B. PEI advertises an EVPN MAC route for MAC-OI to PE3. The BGP update includes the route-target value configured for VPRN 15.
- C. PE3 advertises a VPN-IPv4 route for prefix 10.10.1.0/24 to PE4. The BGP update includes an MPLS service label.
- D. PE4 advertises an EVPN IP-Prefix route for prefix 10.10.1.0/24 to PE2. The BGP update includes MAC-04 as an overlay index.
Answer:
D
Explanation:
PE4 does not advertise an EVPN IP-Prefix route for prefix 10.10.1.0/24 to PE2.
PE4 advertises a VPN-
IPv4 route for prefix 10.10.1.0/24 to PE2, which includes the MPLS service label of VPRN 152
.
Verified Reference:
Nokia Ethernet Virtual Private Network Services Course | Nokia
Question 3
Examine the exhibit.
Which of the following statements about the operation of VPLS 20 is TRUE?
- A. The flooding list maintained by PEI for VPLS 20 contains three entries: PE2, PE3, and PE4.
- B. PE3 advertises an IMET route to PEI when its VPLS 20's mesh-SDP becomes operationally UP.
- C. PE3 signals a service label to PE4 when its VPLS 20 is enabled and is bound to an operational SDP.
- D. PEI advertises a MAC route for MAC-OI when its VPLS 2(Ys SAP becomes operationally UP.
Answer:
D
Explanation:
PE1 does not advertise a MAC route for MAC-01 when its VPLS 20’s SAP becomes operationally
UP.
PE1 advertises an EVPN MAC/IP route for MAC-01, which includes the IP address of Host 1 and
the ESI of the Ethernet segment1
.
Verified Reference:
Ethernet Virtual Private Networks (EVPNs)
Question 4
Examine the exhibit.
Which of the following configuration is NOT required to enable Layer-2 communication between CEI
and CE2?
- A. Configure an MP-BGP session that allows the exchange of EVPN routes between PEI and PE3.
- B. Configure an MP-BGP session that allows the exchange of IPv4 labeled routes between PE3 and PE4.
- C. Configure a service distribution point (SDP) on PE3 to reach PE4, and another SDP on PE4 to reach PE3.
- D. Configure a local attachment circuit (AC) and a remote AC for VPWS 4 on all PE routers.
Answer:
C
Explanation:
The advertisement of IP-Prefix routes is not required to enable Layer-2 communication between CE1
and CE2. IP-Prefix routes are used to enable Layer-3 communication between different subnets in an
EVPN-IRB service.
For Layer-2 communication, only MAC/IP routes are required2
.
Verified Reference:
Nokia Ethernet Virtual Private Network Services Course | Nokia
Question 5
In the exhibit, VPWS 4 enables communications between CEI and CE2. Which of the following
statements regarding the operation of VPWS 4 is FALSE?
- A. PEI advertises an auto-discovery per EVPN instance (A-D per EVI) route to PE3 as soon as the SAP becomes operationally
- B. PE3 advertises an IMET route to PEI as soon as VPWS 4 is administratively enabled.
- C. PEI and PE3 exchange their service labels using A-D per EVI routes.
- D. PE3 and PE4 exchange their service labels over an established targeted LDP session.
Answer:
C
Explanation:
PE1 and PE3 do not exchange their service labels using A-D per EVI routes.
PE1 and PE3 exchange
their service labels using MAC routes, which are advertised when their local ACs become
operationally UP1
.
Verified Reference:
Ethernet Virtual Private Networks (EVPNs)
Question 6
Examine the exhibit.
Which of the following configuration conditions is required for the proper operation of EVPN VPWS
2?
- A. The local AC tag ID configured on PE2 must match the local AC tag ID configured on PEI.
- B. The remote AC tag ID configured on PE2 must match the remote AC tag ID configured on PE3.
- C. The local AC tag ID and the remote AC tag ID configured on PE2 must match.
- D. The local AC tag ID configured on PEI must match the local AC tag ID configured on PE3.
Answer:
A
Explanation:
The local AC tag ID configured on PE2 must match the local AC tag ID configured on PE1. This ensures
that the tag IDs are consistent across both ends of the VPWS service.
The remote AC tag ID
configured on PE2 does not need to match the remote AC tag ID configured on PE3, as long as they
are unique within each PE1
.
Verified Reference:
Ethernet Virtual Private Networks (EVPNs)
Question 7
Examine the exhibit.
Which of the following statements about the operation of EVPN VPWS 4 is FALSE?
- A. PEI brings the SAP in VPWS 4 operationally down.
- B. PE3 sets the P flag in its advertised A-D per EVI route to I.
- C. PE2 receives a single A-D per EVI route. The route is originated from PE3.
- D. PE2 receives two A-D per ES routes: one from PEI and another from PE3.
Answer:
B
Explanation:
PE3 does not set the P flag in its advertised A-D per EVI route to 1. PE3 sets the P flag to 0, indicating
that it is not the DF for EVI 20.
PE1 sets the P flag to 1, indicating that it is the DF for EVI 201
.
Verified Reference:
Ethernet Virtual Private Networks (EVPNs)
Question 8
Examine the exhibit.
Which of the following statements about the EVPN routes exchanged for EVPN VPWS 2 is TRUE?
- A. PEI advertises an A-D per EVI route that includes a tag ID set to 40.
- B. PEI advertises an A-D per EVI route that includes a non-zero Layer-2 MTLJ.
- C. PE2 advertises an A-D per EVI route that includes a P flag set to I.
- D. All PES advertise a MAC route that includes a non-zero MPLS label.
Answer:
D
Explanation:
All PEs do not advertise a MAC route that includes a non-zero MPLS label. Only PE1 advertises a MAC
route that includes a non-zero MPLS label, which is used by PE2 to forward traffic to PE1.
PE2 and
PE3 do not advertise any MAC routes for VPWS 21
.
Verified Reference:
Ethernet Virtual Private Networks (EVPNs)
Question 9
Which of the following statements about the operation of a single-homed EVPN VPWS is TRUE?
- A. The same tag ID must be configured for the local attachment circuit (AC) at each PE.
- B. Each PE advertises a MAC route and an A-D per EVI route when its local AC becomes operationally UP.
- C. The advertised A-D per EVI route includes a non-zero tag ID and a non-zero MPLS label.
- D. Each PE verifies that the received tag ID matches its configured local AC tag ID.
Answer:
C
Explanation:
The advertised A-D per EVI route includes a non-zero tag ID and a zero MPLS label.
The tag ID is used
to identify the VPWS service, while the MPLS label is not used for single-homed VPWS services1
.
Verified Reference:
Ethernet Virtual Private Networks (EVPNs)
Question 10
Which of the following statements about the EVPN Layer 2 Attributes extended community is FALSE?
- A. It is advertised with the auto-discovery per EVPN instance (A-D per EVI) route.
- B. It is applicable to EVPN VPLS services.
- C. It specifies the service maximum transmission unit (MTU).
- D. It specifies a P flag that indicates whether the advertising PE is a primary PE.
Answer:
B
Explanation:
The EVPN Layer 2 Attributes extended community is not applicable to EVPN VPLS services.
It is
applicable to EVPN VPWS services, where it carries information such as the tag ID and the service
MTU1
.
Verified Reference:
Ethernet Virtual Private Networks (EVPNs)
Question 11
In the exhibit, PE2 is receiving an EVPN auto-discovery (A-D) route from PEI. Based on the output,
which of the following statements is FALSE?
- A. This route is an A-D per EVPN instance (A-D per EVI) route advertised by PEI for a VPWS.
- B. This route indicates that the EVPN service configured on PEI is multi-homed.
- C. This route indicates that the EVPN service is configured on PEI with an EVPN instance (EVI) of 113.
- D. This route indicates that the EVPN service is configured on PEI with a service MTU of 1514.
Answer:
D
Explanation:
This route indicates that the EVPN service is configured on PE1 with a service MTU of 1500, not 1514.
The service MTU is indicated by the MPLS label value in hexadecimal format. The MPLS label value of
0x05DC corresponds to a decimal value of 1500.
Question 12
Which of the following EVPN routes are exchanged to support the operation of a multi-homed EVPN
VPWS?
- A. Auto-discovery per EVPN instance (A-D per EVI) routes and Auto-discovery per Ethernet segment (A-D per ES) routes only
- B. MAC/IP routes, A-D per EVI routes, and A-D per ES routes
- C. A-D per EVI routes, A-D per ES routes, and Ethernet segment (ES) routes
- D. A-D per EVI routes and ES routes only
Answer:
C
Explanation:
A-D per EVI routes, A-D per ES routes, and Ethernet segment (ES) routes are exchanged to support
the operation of a multi-homed EVPN VPWS. These routes are used to discover all PEs associated
with an Ethernet segment, indicate the redundancy mode of the Ethernet segment, and elect the
designated forwarder for each service.
Question 13
In the exhibit,
VPLS 20 is associated with a single-active Ethernet segment on routers PEI and PE3. Which of the
following statements is FALSE?
- A. PEI advertises an A-D per ES route which indicates that ESI 1 is operating in a single-active redundancy mode.
- B. PEI advertises an A-D per EVI route which includes a P flag set to I to indicate that PEI is the DF for EVI 20.
- C. PE3 advertises an A-D per ES route which indicates that ESI I is operating in a single-active redundancy mode.
- D. When PEI learns MAC-01, it advertises a MAC/IP route which indicates that MAC-OI is associated with ESI I.
Answer:
D
Explanation:
When PE1 learns MAC-01, it advertises a MAC/IP route which indicates that MAC-01 is associated
with ESI 1. This route is used by remote PEs to populate their FDBs with MAC-01 and its
corresponding ESI.
Question 14
Examine the exhibit.
Which of the following actions is performed by PEI after it receives a BUM packet from CEI?
- A. PEI does not flood the packet because PEI is acting as non-designated forwarder (non-DF) for VPLS 10.
- B. PEI sends the packet to PE2 but not to PE3 because PE3 is connected to the originating ES.
- C. PEI sends the packet to PE2 and to PE3. An ESI label is included only in the packet sent to PE2.
- D. PEI sends the packet to PE2 and to PE3. An ESI label is included only in the packet sent to PE3.
Answer:
C
Explanation:
PE1 sends the packet to PE2 and to PE3. An ESI label is included only in the packet sent to PE2. The
ESI label is used to implement the split-horizon mechanism and prevent traffic duplication. The
packet sent to PE3 does not need an ESI label because PE3 is connected to the same Ethernet
segment as PE1.
Question 15
In the exhibit, an EVI range is configured and the preference-based algorithm is used to elect the
designated forwarder (DF) on ESI 1. Which PE is elected as DF for VPLS 10?
- A. PEI
- B. PE2
- C. PE3
- D. PE4
Answer:
C
Explanation:
PE3 is elected as DF for VPLS 10. The preference-based algorithm uses the highest preference value
of the PEs attached to the same Ethernet segment as the tie-breaker criterion. PE3 has the highest
preference value among PE1, PE2, and PE3.