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This option proposes: Verify the match criteria and behavior binding in a Modular QoS Command-Line configuration before investigating packet-marking or policing failures. It addresses the different topic Huawei MQC traffic classification and behavior binding, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Trace ACL rule matching and interface direction before broadening a security filter that drops legitimate traffic. It addresses the different topic ACL traffic filter placement and rule order, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Analyze Virtual Router Redundancy Protocol master election using priorities and the virtual router ID instead of a router's physical interface address alone. It addresses the different topic VRRP master election priority and tie breaks, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Prefix filters can test network address plus mask range, and permit or deny effects depend on how the list is referenced; a matching address alone does not imply every more-specific subnet is included. It addresses the different topic IP prefix filtering and exact route-match conditions, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: IS-IS uses CLNS-based network entities and level-specific hellos; level-1 neighbors normally require compatible area membership, while level-2 adjacencies have different area constraints and still need link and authentication compatibility. It addresses the different topic IS-IS area addresses and adjacency prerequisites, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Redistributing between routing protocols can create route feedback, suboptimal preference or loops unless policies identify origins, limit permitted prefixes and use suitable tagging or filtering. It addresses the different topic Route redistribution feedback loops and route tags, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Inspect the prefix-list rule sequence, base prefix, greater-than/less-than mask conditions and test routes immediately inside and outside the intended range. It addresses the different topic IP prefix filtering and exact route-match conditions, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Inspect OSPF neighbor states and interface detail on both ends, including area IDs, hello/dead intervals, network type and authentication settings. It addresses the different topic OSPF adjacency prerequisites and mismatched parameters, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Inspect classifier match counters, behavior actions, traffic-policy associations, interface attachment and ingress/egress direction. It addresses the different topic Huawei MQC traffic classification and behavior binding, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

That option concerns ACL traffic filter placement and rule order. That follows from the targeted Recommended action: Differentiate traffic policy-based routing on a matching packet from ordinary destination-based forwarding through the best RIB route.

That option concerns Route redistribution feedback loops and route tags. That follows from the targeted Recommended action: Differentiate traffic policy-based routing on a matching packet from ordinary destination-based forwarding through the best RIB route.

That option concerns BGP route reflector and cluster loop prevention. That follows from the targeted Recommended action: Differentiate traffic policy-based routing on a matching packet from ordinary destination-based forwarding through the best RIB route.

This option proposes: Troubleshoot a site-to-site IPsec tunnel by separating IKE security-association establishment from protected ESP payload transport. It addresses the different topic IPsec VPN IKE negotiation versus ESP data channel, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Review packet source and destination fields, rule sequence, actual interface ingress or egress attachment and matching counters. It addresses the different topic ACL traffic filter placement and rule order, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Check the MED value and the policy context before using BGP advertisements to suggest which entry link another AS should prefer. It addresses the different topic BGP MED interpretation between neighboring autonomous systems, not the directly tested Policy-based routing versus destination routing failure in the stated incident (An engineer deploys a policy route for one subnet but sees unmatched traffic still use the global best route and mistakenly considers that a failure.).

This option proposes: Explain the DIS role on broadcast IS-IS circuits and why it differs from an OSPF DR/BDR election. It addresses the different topic IS-IS designated intermediate system and pseudonode, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Differentiate traffic policy-based routing on a matching packet from ordinary destination-based forwarding through the best RIB route. It addresses the different topic Policy-based routing versus destination routing, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Use a carefully scoped Huawei IP prefix list to match the intended route ranges and prefix lengths before applying an import or export policy. It addresses the different topic IP prefix filtering and exact route-match conditions, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: PBR can steer selected packets based on additional attributes such as source or application criteria, with fallback behavior defined by policy; it does not require the routing protocol to advertise a new destination prefix. It addresses the different topic Policy-based routing versus destination routing, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Redistributing between routing protocols can create route feedback, suboptimal preference or loops unless policies identify origins, limit permitted prefixes and use suitable tagging or filtering. It addresses the different topic Route redistribution feedback loops and route tags, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: An ABR can summarize inter-area routes and an ASBR can summarize redistributed external routes; aggregation reduces route detail but can hide component failures or create blackholes without safeguards. It addresses the different topic OSPF summarization at ABR and ASBR, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Compare area addresses, supported router levels, L1 and L2 link-state databases and the attached-bit/default-route behavior toward external areas. It addresses the different topic IS-IS level one versus level two reachability, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Inspect the prefix-list rule sequence, base prefix, greater-than/less-than mask conditions and test routes immediately inside and outside the intended range. It addresses the different topic IP prefix filtering and exact route-match conditions, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Inspect traffic classifier matches, policy routing next-hop eligibility, egress statistics and the normal destination route that would otherwise apply. It addresses the different topic Policy-based routing versus destination routing, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

That option concerns OSPF router network and summary LSA scope. That follows from the targeted action: Verify the match criteria and behavior binding in a Modular QoS Command-Line configuration before investigating packet-marking or policing failures.

That option concerns Route redistribution feedback loops and route tags. That follows from the targeted action: Verify the match criteria and behavior binding in a Modular QoS Command-Line configuration before investigating packet-marking or policing failures.

That option concerns IP prefix filtering and exact route-match conditions. That follows from the targeted action: Verify the match criteria and behavior binding in a Modular QoS Command-Line configuration before investigating packet-marking or policing failures.

This option proposes: Bidirectionally redistribute every OSPF and IS-IS route at both borders with no filtering because both protocols independently prevent all interprotocol loops. It addresses the different topic Route redistribution feedback loops and route tags, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Alter all BGP route advertisements merely to steer one approved source subnet's web traffic and assume there is no separate policy-routing mechanism. It addresses the different topic Policy-based routing versus destination routing, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Assume the switch with the fastest interface always becomes the spanning-tree root even when a lower bridge ID exists elsewhere. It addresses the different topic RSTP designated root and backup topology selection, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (An access switch has a voice traffic classifier defined but traffic statistics reveal no packets matched after an engineer forgot to apply the policy to the uplink.).

This option proposes: Check route-policy matching conditions, node permit/deny behavior and application direction before fixing unexpected accepted or rejected routes. It addresses the different topic Route-policy node and filtering direction, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (A carrier marks video packets in an outbound traffic behavior but accidentally attaches the policy in the ingress direction and sees no expected QoS effect.).

This option proposes: Trace IS-IS link-state synchronization through LSP sequence numbers and summary or acknowledgment PDUs when databases differ. It addresses the different topic IS-IS LSP synchronization using CSNP and PSNP, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (A carrier marks video packets in an outbound traffic behavior but accidentally attaches the policy in the ingress direction and sees no expected QoS effect.).

This option proposes: Use a carefully scoped Huawei IP prefix list to match the intended route ranges and prefix lengths before applying an import or export policy. It addresses the different topic IP prefix filtering and exact route-match conditions, not the directly tested Huawei MQC traffic classification and behavior binding failure in the stated incident (A carrier marks video packets in an outbound traffic behavior but accidentally attaches the policy in the ingress direction and sees no expected QoS effect.).