Alcatel-Lucent Border Gateway Protocol - 4A0-102 Exam Questions [2026]

QUESTION NO: 1
Click the exhibit.

AS 65550 owns CIDR block 10.64.0.0/12. Router R3 is advertising Client1 and Client2 networks into BGP. Router R6
advertises the aggregate 10.64.0.0/12 to AS 65541 with "summary-only" enabled. Which of the following routes are
received by router R7?

A. Client1, Client2 and the aggregate. B. Only the aggregate. C. Only Client1 and the aggregate. D. Only Client2 and the aggregate.

Correct Answer: C

QUESTION NO: 2
Click the exhibit.

After router A receives the BGP update for the 10.3.3.0/24 prefix, which routers will the route be propagated to?

A. All routers with which it has a BGP session, except the router it received the update from, which is router B. All routers with which it has a BGP session, except the router it received the update from, which is router C. All routers with which it has a BGP session, except the router it received the update from, which is router D. All routers with which it has a BGP session. E. Only eBGP neighbors.

Correct Answer: E

QUESTION NO: 3
Click the exhibit.

Router R1 is a route reflector with clients R2, R5 and R6. Router R3 advertises the prefix 192.168.1.0/27 to routers R5
and R6. Assuming that routers R1, R2 and R4 are configured with "add-paths ipv4 send 2 receive", what is the
expected output of "show router bgp routes" when executed on router R2?

A. Option A B. Option C C. Option D D. Option B

Correct Answer: A

QUESTION NO: 4
BGP is configured on two peers, routers A and B.
Router A is configured with a Hold Time timer of 60 seconds and a
Keepalive timer of 25 seconds. Router B is configured with a Hold Time timer of 90 seconds and a Keepalive timer of
70 seconds. What will the active Keepalive timer be on router B?

A. 20 seconds B. 25 seconds C. 30 seconds D. 70 seconds

Correct Answer: A

QUESTION NO: 5
Which of the following regarding the TTL of a BGP message is TRUE?

A. TTL is a well-known mandatory BGP attribute. B. The default TTL value of an iBGP message can be modified using the multihop command. C. The default TTL value of an eBGP message can be modified using the "ttl-security" command. D. The default TTL value of an eBGP message is 1, and 64 for an iBGP message.

Correct Answer: D

QUESTION NO: 6
Which of the following statements regarding BGP FRR is FALSE?

A. BGP peer-tracking can be used to improve BGP FRR failure detection times. B. BGP FRR can be triggered by BFD. C. The router must receive several BGP routes to compute a backup path. D. The backup path can use the same next hop as the primary path.

Correct Answer: D

QUESTION NO: 7
Click the exhibit.

Considering that both routers C and D are advertising the eBGP learned prefix 10.5.0.0/16 into ISP X, which of the
following best describes the route advertisement within ISP X?

A. Router C sends the update to routers E and F only. B. Router C sends the update to routers D, E and F. C. Router C sends the update to routers A, B, D, E and F. D. Router C sends the update to routers A, B, E and F.

Correct Answer: C

QUESTION NO: 8
Based on the default settings for the Alcatel-Lucent 7750 SR, when a policy change is made and committed, what
action is required by the user for the change to take effect?

A. No further action is required. B. Execute a command to reset the BGP session with the affected peer or peers. C. Execute a command to re-evaluate all routes in the RIB-In against the configured import policies. D. Execute a command to re-evaluate all routes in the Local-RIB against the configured export policies.

Correct Answer: A