Juniper JN0-650 Practice Test 36
Question 350
A classifier places premium voice and ordinary data in the same loss priority. Select TWO statements that correctly combine the Packet loss priority PLP marking implementation, its evidence, or its governing principle.
- Congestion accounting distinguishes low-PLP and high-PLP traffic as intended.
- Set IP TTL to a high value and assume packet loss priority becomes low.
- Assign deliberate PLP values through classification or policing policy.
- Configure suitable RED or WRED drop profiles and map PLP to planned thresholds.
- Define suitable forwarding classes and their supported queue mappings.
Explanation
Correct Answers
A:Congestion accounting distinguishes low-PLP and high-PLP traffic as intended. This is direct observable evidence for Packet loss priority PLP marking.
C:Assign deliberate PLP values through classification or policing policy. This is the intended implementation action for Packet loss priority PLP marking.
Incorrect Answers
B:Set IP TTL to a high value and assume packet loss priority becomes low. This would not be an appropriate Packet loss priority PLP marking decision. Treating every packet as identical PLP may defeat differentiated congestion policy.
D:Configure suitable RED or WRED drop profiles and map PLP to planned thresholds. This belongs to RED WRED drop profile thresholds, not the specified Packet loss priority PLP marking operation. Packet loss priority influences drop likelihood independent of forwarding class alone.
E:Define suitable forwarding classes and their supported queue mappings. This belongs to Junos forwarding class to queue mapping, not the specified Packet loss priority PLP marking operation. Packet loss priority influences drop likelihood independent of forwarding class alone.
Question 351
Short bursts cause packet drops although average throughput remains below line rate. After deploying the recommended Queue buffer-size allocation change, which result MOST directly verifies success?
- Captures and counters explain ingress class egress queue and final header marking.
- Other areas see the approved aggregate while required specifics remain reachable.
- Queue statistics show probabilistic early drops according to class and PLP settings.
- Bursty traffic sees acceptable loss with controlled memory usage.
Explanation
Correct Answer
D:Bursty traffic sees acceptable loss with controlled memory usage. This is the directly observable outcome for Queue buffer-size allocation. Egress buffers absorb short bursts but cannot compensate for persistent overload.
Incorrect Answers
A:Captures and counters explain ingress class egress queue and final header marking. This validates CoS processing order ingress to egress but does not directly demonstrate the required Queue buffer-size allocation result. Egress buffers absorb short bursts but cannot compensate for persistent overload.
B:Other areas see the approved aggregate while required specifics remain reachable. This validates OSPF interarea route summarization but does not directly demonstrate the required Queue buffer-size allocation result. Egress buffers absorb short bursts but cannot compensate for persistent overload.
C:Queue statistics show probabilistic early drops according to class and PLP settings. This validates RED WRED drop profile thresholds but does not directly demonstrate the required Queue buffer-size allocation result. Egress buffers absorb short bursts but cannot compensate for persistent overload.
Question 352
During an operational risk review, this situation is reported: A Junos VSTP domain unintentionally selects one root for all VLANs. If the underlying control is neglected, which failure would MOST directly follow?
- Misconfigured VLAN-specific roots can send traffic over inefficient links.
- Assuming a learned VLAN is permanently present can break traffic after withdrawals.
- Treating primary VLAN membership alone as isolation allows undesired peer traffic.
- An unattached scheduler map has no effect on the live bottleneck port.
Explanation
Correct Answer
A:Misconfigured VLAN-specific roots can send traffic over inefficient links. VSTP runs per-VLAN spanning-tree decisions rather than one shared instance. A useful corrective investigation is to inspect show spanning-tree bridge per VLAN and observed forwarding ports.
Incorrect Answers
B:VSTP runs per-VLAN spanning-tree decisions rather than one shared instance. Assuming a learned VLAN is permanently present can break traffic after withdrawals.
C:VSTP runs per-VLAN spanning-tree decisions rather than one shared instance. Treating primary VLAN membership alone as isolation allows undesired peer traffic.
D:VSTP runs per-VLAN spanning-tree decisions rather than one shared instance. This is a Scheduler maps attached to egress interface failure pattern, not the primary VSTP per-VLAN root distribution failure in this case.
Question 353
A newly added edge router fails to learn the selected RP from its PIM domain. Select TWO statements that correctly combine the PIM RP discovery and bootstrap mapping implementation, its evidence, or its governing principle.
- Use IGMPv3-capable receivers and source-specific membership where applicable.
- Verify PIM sparse-mode SPT switch behavior and source-specific forwarding entries.
- Candidate routers acquire the intended RP mappings for authorized multicast ranges.
- Add a hostname DNS alias and claim it automatically distributes multicast RP election results.
- Configure supported dynamic RP discovery or bootstrap policies where the topology supports them.
Explanation
Correct Answers
C:Candidate routers acquire the intended RP mappings for authorized multicast ranges. This is direct observable evidence for PIM RP discovery and bootstrap mapping.
E:Configure supported dynamic RP discovery or bootstrap policies where the topology supports them. This is the intended implementation action for PIM RP discovery and bootstrap mapping.
Incorrect Answers
A:Use IGMPv3-capable receivers and source-specific membership where applicable. This belongs to IGMPv3 source include mode, not the specified PIM RP discovery and bootstrap mapping operation. Dynamic RP discovery advertises RP group associations while PIM still requires routing reachability.
B:Verify PIM sparse-mode SPT switch behavior and source-specific forwarding entries. This belongs to ASM shared tree versus SPT switchover, not the specified PIM RP discovery and bootstrap mapping operation. Dynamic RP discovery advertises RP group associations while PIM still requires routing reachability.
D:Add a hostname DNS alias and claim it automatically distributes multicast RP election results. This would not be an appropriate PIM RP discovery and bootstrap mapping decision. Incorrect discovery scope or policy leaves segments with stale RP maps.
Question 354
An RR session is Established for inet unicast but not for the EVPN address family. Which next investigation or correction is MOST appropriate?
- Measure ARP flood rate and verify authoritative bindings during host changes.
- Configure only OSPFv2 Hello packets and assume EVPN MAC advertisements are exchanged.
- Inspect BGP family capability and show route table bgp.evpn.0.
- Inspect VNI mapping interface bridge domain and encapsulated VNI values.
Explanation
Correct Answer
C:Inspect BGP family capability and show route table bgp.evpn.0. This checks whether expected EVPN NLRI appears in the routing instance and route table.
Incorrect Answers
A:Measure ARP flood rate and verify authoritative bindings during host changes. That check applies chiefly to EVPN ARP suppression from IP MAC bindings, not the current BGP EVPN address-family peer negotiation issue. EVPN uses MP-BGP control-plane signaling separate from ordinary IPv4 unicast reachability.
B:Configure only OSPFv2 Hello packets and assume EVPN MAC advertisements are exchanged. That bypass leaves the BGP EVPN address-family peer negotiation issue unresolved. Having an IP-connected VTEP does not mean its peer negotiates EVPN NLRI.
D:Inspect VNI mapping interface bridge domain and encapsulated VNI values. That check applies chiefly to VXLAN VNI to VLAN association, not the current BGP EVPN address-family peer negotiation issue. EVPN uses MP-BGP control-plane signaling separate from ordinary IPv4 unicast reachability.
Question 355
Some VLANs loop after the peer changes STP mode or tagging. Which next investigation or correction is MOST appropriate?
- Inspect ethernet-switching table per VLAN and MAC movement logs.
- Check filter terms counters and learned VLAN association for sample ingress frames.
- Capture VLAN-specific BPDUs and compare configured VSTP VLAN lists.
- Configure only OSPF neighbor authentication and assume tagged STP BPDUs become compatible.
Explanation
Correct Answer
C:Capture VLAN-specific BPDUs and compare configured VSTP VLAN lists. This checks whether correct VLAN STP instances exchange control frames and maintain loop-free forwarding.
Incorrect Answers
A:Inspect ethernet-switching table per VLAN and MAC movement logs. That check applies chiefly to Ethernet MAC learning and flooding, not the current VSTP interoperation and VLAN tagging issue. Per-VLAN STP compatibility depends on VLAN tagging and protocol expectations.
B:Check filter terms counters and learned VLAN association for sample ingress frames. That check applies chiefly to Filter-based VLAN assignment, not the current VSTP interoperation and VLAN tagging issue. Per-VLAN STP compatibility depends on VLAN tagging and protocol expectations.
D:Configure only OSPF neighbor authentication and assume tagged STP BPDUs become compatible. That bypass leaves the VSTP interoperation and VLAN tagging issue unresolved. Different BPDU handling per VLAN can leave only some VLANs unprotected.
Question 356
During an operational risk review, this situation is reported: An exchange peer approaches route memory capacity after a misconfigured advertisement. If the underlying control is neglected, which failure would MOST directly follow?
- Exporting internal tags to a peer may disclose internal routing policy semantics.
- Changing the switch IP address does not correct an endpoint access VLAN mismatch.
- No route-count guard can overwhelm route memory or control-plane processing.
- Confusing local preference with Junos route preference can produce wrong active-route reasoning.
Explanation
Correct Answer
C:No route-count guard can overwhelm route memory or control-plane processing. BGP prefix controls limit received-route scale and safeguard resources. A useful corrective investigation is to test near-limit route scenarios and examine neighbor status or alarms.
Incorrect Answers
A:Exporting internal tags to a peer may disclose internal routing policy semantics. This is a BGP communities match and deletion failure pattern, not the primary BGP prefix-limit peer protection failure in this case. BGP prefix controls limit received-route scale and safeguard resources.
B:Changing the switch IP address does not correct an endpoint access VLAN mismatch. This is a Ethernet access interface VLAN membership failure pattern, not the primary BGP prefix-limit peer protection failure in this case. BGP prefix controls limit received-route scale and safeguard resources.
D:Confusing local preference with Junos route preference can produce wrong active-route reasoning. This is a BGP route preference versus OSPF failure pattern, not the primary BGP prefix-limit peer protection failure in this case. BGP prefix controls limit received-route scale and safeguard resources.
Question 357
A prepending policy unexpectedly modifies inbound routes rather than outbound announcements. Which next investigation or correction is MOST appropriate?
- Inspect show route extensive for route preference protocol and active flag.
- Add local-pref to a VLAN interface and assume remote AS_PATH changes automatically.
- Inspect show route advertising-protocol BGP and remote policy confirmation if available.
- Inspect show bgp neighbor and firewall filter counters for TCP179.
Explanation
Correct Answer
C:Inspect show route advertising-protocol BGP and remote policy confirmation if available. This checks whether advertised AS_PATH contains expected local-AS repeats while primary route remains reachable.
Incorrect Answers
A:Inspect show route extensive for route preference protocol and active flag. That check applies chiefly to BGP route preference versus OSPF, not the current BGP AS path prepend outbound advertisement issue. AS_PATH prepending may influence remote inbound selection but is not guaranteed to override peer policy.
B:Add local-pref to a VLAN interface and assume remote AS_PATH changes automatically. That bypass leaves the BGP AS path prepend outbound advertisement issue unresolved. Inserting prepends into all paths can cause unexpected global traffic shifts.
D:Inspect show bgp neighbor and firewall filter counters for TCP179. That check applies chiefly to BGP TCP 179 and firewall reachability, not the current BGP AS path prepend outbound advertisement issue. AS_PATH prepending may influence remote inbound selection but is not guaranteed to override peer policy.
Question 358
A 10-Gbps link and a 100-Gbps link appear to receive indistinguishable default OSPF cost. After deploying the recommended OSPF reference bandwidth and high-speed links change, which result MOST directly verifies success?
- Faster links receive the planned comparative metrics in the routing database.
- The local route table follows documented acceptance policy while LSDB visibility is understood.
- Packets remain inside the permitted IPv6 scope and group memberships reflect the destination.
- The intended eligible DR and BDR appear on the broadcast segment after reelection.
Explanation
Correct Answer
A:Faster links receive the planned comparative metrics in the routing database. This is the directly observable outcome for OSPF reference bandwidth and high-speed links. OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster.
Incorrect Answers
B:The local route table follows documented acceptance policy while LSDB visibility is understood. This validates OSPF routing policy import filtering but does not directly demonstrate the required OSPF reference bandwidth and high-speed links result. OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster.
C:Packets remain inside the permitted IPv6 scope and group memberships reflect the destination. This validates IPv6 multicast scope and group use but does not directly demonstrate the required OSPF reference bandwidth and high-speed links result. OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster.
D:The intended eligible DR and BDR appear on the broadcast segment after reelection. This validates OSPF designated router election broadcast LAN but does not directly demonstrate the required OSPF reference bandwidth and high-speed links result. OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster.
Question 359
A VoIP migration introduces LLDP-MED and DHCP errors at the same access port. Which technical principle BEST explains the IP phone first-hop diagnostic workflow decision?
- OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster.
- IEEE PoE total power budget and per-port allocation constrain powered endpoints.
- Phone access-port design can carry tagged voice and untagged data for separate policies.
- Power negotiation Layer 2 VLAN discovery and IP addressing are separate first-hop gates.
Explanation
Correct Answer
D:Power negotiation Layer 2 VLAN discovery and IP addressing are separate first-hop gates. In this situation, the relevant action is to diagnose PoE physical link LLDP-MED voice VLAN and DHCP stages in order.
Incorrect Answers
A:OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster. That principle is related to OSPF reference bandwidth and high-speed links, not the main IP phone first-hop diagnostic workflow choice. Changing one DHCP option does not repair absent PoE or unsupported LLDP-MED.
B:IEEE PoE total power budget and per-port allocation constrain powered endpoints. That principle is related to PoE power budget switch capacity, not the main IP phone first-hop diagnostic workflow choice. Changing one DHCP option does not repair absent PoE or unsupported LLDP-MED.
C:Phone access-port design can carry tagged voice and untagged data for separate policies. That principle is related to Voice VLAN tagged versus PC data traffic, not the main IP phone first-hop diagnostic workflow choice. Changing one DHCP option does not repair absent PoE or unsupported LLDP-MED.
Question 360
A multicast source exists but group join state never reaches a configured rendezvous point. Select TWO statements that correctly combine the PIM sparse-mode RP shared tree implementation, its evidence, or its governing principle.
- Configure reachable appropriate RP mapping for the required ASM group range.
- Configure an IP host default gateway and assume that automatically elects a PIM RP.
- Use IGMPv3-capable receivers and source-specific membership where applicable.
- (*,G) joins establish a shared tree via the intended RP and receivers get the stream.
- Align multicast RPF expectations with unicast or configured multicast routing topology.
Explanation
Correct Answers
A:Configure reachable appropriate RP mapping for the required ASM group range. This is the intended implementation action for PIM sparse-mode RP shared tree.
D:(*,G) joins establish a shared tree via the intended RP and receivers get the stream. This is direct observable evidence for PIM sparse-mode RP shared tree.
Incorrect Answers
B:Configure an IP host default gateway and assume that automatically elects a PIM RP. This would not be an appropriate PIM sparse-mode RP shared tree decision. Absent or inconsistent RP mapping prevents initial ASM group discovery.
C:Use IGMPv3-capable receivers and source-specific membership where applicable. This belongs to IGMPv3 source include mode, not the specified PIM sparse-mode RP shared tree operation. Sparse-mode ASM commonly uses an RP to establish initial shared-tree multicast state.
E:Align multicast RPF expectations with unicast or configured multicast routing topology. This belongs to Multicast RPF shortest reverse path check, not the specified PIM sparse-mode RP shared tree operation. Sparse-mode ASM commonly uses an RP to establish initial shared-tree multicast state.
