4A0-103 Online Practice Questions and Answers

Which of the following is defined by the following statement? All label mappings received from all peer LSRs are saved.

A. Conservative label retention

B. Liberal label retention.

C. Downstream on demand.

D. Downstream unsolicited.

Click on the exhibit button below. Assume the following:

-Each router's OSPF interfaces are in the areas shown.

-Bidirectional LDP-over-RSVP tunnels extend from routers R1 to R3 and back over the path R1-R4-R5R3.

-You enable fast reroute facility bypass on the R5-R3 RSVP LSP.

-Router R5 acts as a PLR, protecting the R5-R3 link by building a bypass tunnel through router R2.

You build a layer 2 VPN on routers R1 and R3, using the LDP-over-RSVP tunnels. What MPLS configuration step must you complete on router R2 for it to protect the end-to-end service?

A. Enable LDP on the R2-R5 interface.

B. Configure T-LDP sessions between routers R2 and R5 and R3.

C. Configure LDP-over-RSVP support on router R2.

D. Enable MPLS and RSVP on the router R2 network interfaces.

E. Enable LDP on the R2-R5 and R2-R3 interfaces.

Which one of the following statements regarding RSVP LSP configuration is true?

A. LSPs must always terminate on a system ID.

B. MPLS and RSVP must be enabled on all routers.

C. Interfaces must be individually created in RSVP.

D. Path definitions must include at least one hop entry.

What action does a router perform when it looks up the label of an incoming packet in its LFIB and sees that the LFIB maps to an egress label of 3?

A. It requests a new label from the peer that provided this label.

B. It pops the label.

C. It pushes an additional label onto the label stack.

D. It signals a new label to the peer that sent the packet.

Click on the exhibit.

Why might router R2 have a Link LDP session to R1 (10.10.10.1:0) but not to R3 (10.10.10.3:0)?

A. LDP is not configured on R2.

B. R2 does not have a route to 10.10.10.3.

C. LDP is not configured on R3's interface to R2.

D. The targeted session is not configured on R2.

Which of the following about RSVP refresh reduction on a Alcatel-Lucent 7750 SR is FALSE?

A. RSVP generates a summary refresh message for each LSP.

B. Message-IDs replace individual refresh messages.

C. An LSP state change causes the Message-ID to be incremented.

D. RSVP refresh reduction is disabled by default.

What labels are encapsulated in the tunnels used by a 6PE deployment?

A. The inner label is the IPv4 Explicit Null. The outer label is the MPLS transport label,

B. The inner label is an MPLS transport label. The outer label is the IPv4 Explicit Null.

C. The inner label is the IPv6 Explicit Null. The outer label is an MPLS transport label.

D. The inner label is an MPLS transport label. The outer label is the IPv6 Explicit Null.

Click on the exhibit.

The path of a fast reroute protected LSP is R1-R2-R3. Which of the following about the protected LSP path is TRUE?

A. All routers along the path, R1, R2, and R3 can be PLRs.

B. If the R1-R2 link fails, router R4 becomes an MP.

C. If the R2-R3 link fails, router R3 becomes a PLR.

D. Router R1 is the LSP head-end and can be a PLR.

Which of the following about CSPF is TRUE?

A. The tail-end router performs the CSPF calculation for an LSP.

B. CSPF calculations are always performed on RSVP-TE based LSPs.

C. The head-end router performs the CSPF calculation for an LSP.

D. Each downstream router performs its own CSPF calculation for an LSP.

Click on the exhibit.

An LDP tunnel is established on R1-R2-R4-R6 because the link between routers R3 and R6 is down. With the LDP-IGP Sync feature enabled, what happens immediately after the link is restored?

A. A new LDP session is established on R1-R3-R6 as soon as the FIB is updated.

B. The LDP session remains unchanged until the existing path R1-R2-R4-R6 goes down.

C. A new LDP session is established on R1-R3-R6 as soon as router R1 receives a new label for router R6.

D. The LDP session remains unchanged until router R3 stops advertising the maximum metric for the link to router R6.