Online Access Free H12-891_V1.0 Exam Questions

The free mobility function is deployed on the iMaster NCE-Campus on a campus network. Which of the following information should an administrator pay attention to?

• A.Select the policy enforcement point.
• B.Deliver the inter-group policy.
• C.Deploy a policy control matrix.
• D.Define security groups.

In a scenario where a VXLAN tunnel is dynamically established through BGP EVPN, which of the following command needs to be run on the VBDIF interface to enable the VTEP peer to generate BGP EVPN Type 2 routes based on ARP information of the local terminal?

• A.arp-proxy enable
• B.arp collect host enable
• C.arp distribute-gateway enable
• D.mac-address xxxx-xxxx-xxxx

On aCloudCampus virtualized campus network, which of the following modes can be used by afabricto connect to external networks?

• A.Layer 3 shared egress
• B.Layer 3 exclusive egress
• C.Layer 2 exclusive egress
• D.Layer 2 shared egress

The naming of SRv6 instructions complies with certain rules. You can quickly determine the function of an instruction based on the instruction name. Which of the following statements about the keywords in SRv6 instruction names are correct? (Select all that apply)

• A.T: Searches a specified routing table to forward packets.
• B.M: Searches a Layer 2 forwarding table for unicast forwarding.
• C.V: Searches a VPN instance routing table to forward packets.
• D.X: Forwards packets through one or a group of specified Layer 3 interfaces.

Complete the basic processing procedure for DiffServ model-based QoSshown in the figure

Correct Answer:

Explanation:
TheDifferentiated Services (DiffServ) modelforQuality of Service (QoS)enables traffic management based on predefined priorities. This involvesclassifying, policing, queuing, and scheduling trafficto ensure efficient network resource utilization.
Breakdown of Each QoS Processing Step:
#Step 1: Traffic Classification and Marking
Purpose:Identifies and marks packets based onQoS attributessuch asDSCP (Differentiated Services Code Point) or 802.1p priority bits.
Function:Assigns aQoS labelto packets for further processing.
Example:Packets carryingvoice traffic (EF - Expedited Forwarding)are marked forhigh-prioritytreatment.
#Step 2: Traffic Policing (CAR - Committed Access Rate)
Purpose:Enforcesbandwidth limitson specific traffic flows to prevent excessive usage.
Function:Drops or re-marks packetsexceeding the assigned bandwidth threshold.
Example:If avideo stream exceeds 10 Mbps, excess packets may bedropped or re-marked.
#Step 3: Congestion Management (Queuing and Scheduling)
Purpose:Managestraffic flow through queuesbased on assigned QoS levels.
Function:Places packets in appropriatepriority queues (e.g., Strict Priority, Weighted Fair Queuing - WFQ, CBWFQ).
Example:Voice packets are assigned tohigh-priority queuesforlow-latency forwarding.
#Step 4: Congestion Avoidance
Purpose:Prevents networkbuffer overflows and excessive packet drops.
Function:Uses mechanisms likeWRED (Weighted Random Early Detection)to drop lower-priority packets before congestion occurs.
Example:If a queuereaches 80% capacity, WRED may droplow-priority packetsto maintain QoS.
#Step 5: Traffic Shaping
Purpose:Smooths out traffic burststo maintain a consistenttransmission rate.
Function:Buffers and delays packetsto prevent excessive packet drops.
Example:Ifoutgoing traffic exceeds 50 Mbps, shaping ensures itdoes not exceedthis limit while maintaining steady flow.