SR-MPLS is enabled on all routers. The label information encapsulated by R1 into a data packet is shown in the figure. Which of the following MPLS labels is carried in the data packet when it is sent from R2 to R4?
Question 6 of 40
Correct Answer: B
The MPLS label stack originating from R1 encapsulates the path information through the network. When a packet traverses through intermediary routers, each router swaps the top label with the appropriate label for the next hop. Starting from R1, the packet is labeled with 2013 (R1 to R3), then 2032 (R3 to R2), and then 2024 (R2 to R4). When R2 forwards the packet to R4, it uses the top label 2024 because that’s the next hop label instructed by the label switching mechanism.
Question 7 of 40
On a medium-sized network configured with BGP, two RRs are typically deployed to improved BGP RR reliability. Typically, the cluster IDs of the two RRs are set as the same. Which of the following is the reason for that?
Correct Answer: A
In a BGP network, using the same cluster ID for Route Reflectors (RRs) helps to prevent routing loops. When RRs have the same cluster ID, they recognize updates coming from other RRs within the same cluster and avoid retransmitting these updates. This mechanism helps to ensure that routing information is not circulated in loops, which would lead to routing inefficiencies and potential instability in the network. While memory insufficiency and sub-optimal routes are concerns with BGP, the primary reason for using the same cluster ID in multiple RRs is to prevent routing loops.
Question 8 of 40
Which of the following BGP route attributes cannot be used to control BGP route selection?
Correct Answer: D
The Originator ID is not used to control BGP route selection. The Originator ID is a BGP attribute that is used to prevent routing information loops within a single BGP Autonomous System (AS) when Route Reflectors (RRs) are deployed. It helps avoid the reflection of routes back to the originator router. However, it is not involved in the process of BGP route selection or influencing the best path selection process.
Question 9 of 40
On the network shown, an engineer uses two routers to test IPv6 services by running BGP4+ to simulate the communication between the enterprise headquarters and a branch. The engineer checks an Update message sent by R1. Which of the following statements about the message information is correct?
Correct Answer: D
The correct answer is that the route address prefix (including the prefix length) described in the message is 2001:db8:2345:1::1/128. This information is directly indicated in the UPDATE message under the 'Network layer reachability information' field, where it states '2001:db8:2345:1::1/128,' describing the route address prefix accurately paired with the correct prefix length of 128.
Question 10 of 40
What is the largest number of CPEs that a site can support in the Huawei SD-WAN Solution?
Correct Answer: D
The largest number of CPEs that a site can support in the Huawei SD-WAN Solution is 4. This is based on the configuration capabilities of the Huawei SD-WAN, which allows a site to be equipped with multiple CPEs for redundancy and load balancing purposes.