Juniper JN0-650 Practice Test 17
Question 160
A fabric expects active-active service but one leaf never forwards eligible traffic. Which technical principle BEST explains the EVPN all-active multihoming forwarding decision?
- BGP path eligibility depends on successful next-hop resolution in the routing table.
- EVPN IP/MAC learning can support distributed ARP suppression where platforms support it.
- Type3 IMET routes signal participation in an EVPN broadcast domain for BUM distribution.
- EVPN all-active multihoming can use parallel forwarding paths with designated loop protection.
Explanation
Correct Answer
D:EVPN all-active multihoming can use parallel forwarding paths with designated loop protection. In this situation, the relevant action is to configure supported all-active multihoming mode and compatible LAG or ESI settings.
Incorrect Answers
A:BGP path eligibility depends on successful next-hop resolution in the routing table. That principle is related to BGP next-hop reachability hidden route, not the main EVPN all-active multihoming forwarding choice. Treating both uplinks as independent uncoordinated bridges can form duplication or loops.
B:EVPN IP/MAC learning can support distributed ARP suppression where platforms support it. That principle is related to EVPN ARP suppression from IP MAC bindings, not the main EVPN all-active multihoming forwarding choice. Treating both uplinks as independent uncoordinated bridges can form duplication or loops.
C:Type3 IMET routes signal participation in an EVPN broadcast domain for BUM distribution. That principle is related to EVPN Type3 IMET inclusive multicast routes, not the main EVPN all-active multihoming forwarding choice. Treating both uplinks as independent uncoordinated bridges can form duplication or loops.
Question 161
An application receives bursts only after repeated PIM state clearing. Which technical principle BEST explains the Multicast troubleshooting separate control and data planes decision?
- Multicast involves host membership router tree state and actual forwarding traffic.
- RPF uses source or RP reachability and can change when unicast routing changes.
- OSPF E1 includes internal cost to ASBR whereas E2 comparison primarily uses external metric.
- Multicast routing policy or scoping constrains distribution without changing sender addresses.
Explanation
Correct Answer
A:Multicast involves host membership router tree state and actual forwarding traffic. In this situation, the relevant action is to troubleshoot source activity group membership RPF PIM joins and data packet counters in order.
Incorrect Answers
B:RPF uses source or RP reachability and can change when unicast routing changes. That principle is related to Multicast source route policy and RPF, not the main Multicast troubleshooting separate control and data planes choice. Seeing an IGMP group alone does not prove an active source or valid routed data path.
C:That principle is related to OSPF external type-one versus type-two metrics, not the main Multicast troubleshooting separate control and data planes choice.
D:Multicast routing policy or scoping constrains distribution without changing sender addresses. That principle is related to Multicast policy group scoping, not the main Multicast troubleshooting separate control and data planes choice. Seeing an IGMP group alone does not prove an active source or valid routed data path.
Question 162
An early broad classification term captures all traffic before a more specific guest rule. Which configuration or operational step BEST meets the stated requirement?
- Configure community secondary roles and the appropriate promiscuous uplink association.
- Duplicate the broad term and expect later specific terms to override it.
- Reorder policy terms so specific supported VLAN matches precede broad fallback actions.
- Set explicit MSTI bridge priorities in the intended MST region.
Explanation
Correct Answer
C:Reorder policy terms so specific supported VLAN matches precede broad fallback actions. Filter terms are evaluated in policy order subject to terminating actions. The expected validation is that intended guest frames match their rule and general traffic uses the appropriate default.
Incorrect Answers
A:Configure community secondary roles and the appropriate promiscuous uplink association. This addresses Private VLAN community and promiscuous roles rather than the required Filter-based VLAN rule precedence decision. Filter terms are evaluated in policy order subject to terminating actions.
B:Duplicate the broad term and expect later specific terms to override it. This is a risky or ineffective shortcut for Filter-based VLAN rule precedence. Broad first-match conditions can eclipse later VLAN classification terms.
D:Set explicit MSTI bridge priorities in the intended MST region. This addresses MSTP instance root selection rather than the required Filter-based VLAN rule precedence decision. Filter terms are evaluated in policy order subject to terminating actions.
Question 163
An import from a connected route unexpectedly redistributes unrelated management prefixes. Which next investigation or correction is MOST appropriate?
- Review show ospf neighbor state priorities and network type before a controlled restart.
- Compare export term counters originator LSDB and external destinations on a neighbor.
- Compare interarea LSAs and test addresses at aggregate boundaries.
- Configure an interface description containing export and assume it becomes a routing policy.
Explanation
Correct Answer
B:Compare export term counters originator LSDB and external destinations on a neighbor. This checks whether neighbors learn intended external LSAs without importing restricted management networks.
Incorrect Answers
A:Review show ospf neighbor state priorities and network type before a controlled restart. That check applies chiefly to OSPF designated router election broadcast LAN, not the current OSPF external export policy redistribution issue. Junos OSPF export policies govern which eligible routes enter OSPF as externals.
C:Compare interarea LSAs and test addresses at aggregate boundaries. That check applies chiefly to OSPF interarea route summarization, not the current OSPF external export policy redistribution issue. Junos OSPF export policies govern which eligible routes enter OSPF as externals.
D:Configure an interface description containing export and assume it becomes a routing policy. That bypass leaves the OSPF external export policy redistribution issue unresolved. An overly permissive export can leak private or unreachable prefixes across the domain.
Question 164
A large webcast is flooding every access port in a multicast-enabled VLAN. After deploying the recommended IGMP snooping access-port replication change, which result MOST directly verifies success?
- Multicast frames reach receiver ports instead of every port by default.
- (S,G) state forwards only the desired source without RP discovery for SSM.
- Flapping prefixes are damped according to intended thresholds and recover within acceptable time.
- A consistent state chain from source to receivers explains successful data delivery.
Explanation
Correct Answer
A:Multicast frames reach receiver ports instead of every port by default. This is the directly observable outcome for IGMP snooping access-port replication. IGMP snooping uses observed host joins to constrain layer-2 multicast replication.
Incorrect Answers
B:(S,G) state forwards only the desired source without RP discovery for SSM. This validates SSM without rendezvous point but does not directly demonstrate the required IGMP snooping access-port replication result. IGMP snooping uses observed host joins to constrain layer-2 multicast replication.
C:Flapping prefixes are damped according to intended thresholds and recover within acceptable time. This validates BGP route damping flap penalty but does not directly demonstrate the required IGMP snooping access-port replication result. IGMP snooping uses observed host joins to constrain layer-2 multicast replication.
D:A consistent state chain from source to receivers explains successful data delivery. This validates Multicast troubleshooting separate control and data planes but does not directly demonstrate the required IGMP snooping access-port replication result. IGMP snooping uses observed host joins to constrain layer-2 multicast replication.
Question 165
A regional ABR advertises intra-area prefixes but cannot move routes across the backbone. Which technical principle BEST explains the OSPF area-border backbone connectivity decision?
- OSPFv3 separates neighbor topology information from IPv6 prefix dissemination.
- OSPF database exchange can stall when peers disagree on interface MTU.
- MSTP can group VLANs into instances with independent root bridge elections.
- Standard multi-area OSPF uses the backbone to exchange interarea information.
Explanation
Correct Answer
D:Standard multi-area OSPF uses the backbone to exchange interarea information. In this situation, the relevant action is to restore valid area 0 backbone connectivity and supported ABR relationships.
Incorrect Answers
A:OSPFv3 separates neighbor topology information from IPv6 prefix dissemination. That principle is related to OSPFv3 IPv6 prefix advertisement, not the main OSPF area-border backbone connectivity choice. Designing arbitrary direct interarea exchanges without a backbone can partition routing.
B:OSPF database exchange can stall when peers disagree on interface MTU. That principle is related to OSPF interface MTU mismatch, not the main OSPF area-border backbone connectivity choice. Designing arbitrary direct interarea exchanges without a backbone can partition routing.
C:MSTP can group VLANs into instances with independent root bridge elections. That principle is related to MSTP instance root selection, not the main OSPF area-border backbone connectivity choice. Designing arbitrary direct interarea exchanges without a backbone can partition routing.
Question 166
A new authentication policy is installed yet active endpoint sessions retain old roles. Which next investigation or correction is MOST appropriate?
- Keep all ports in server-fail mode indefinitely after the server is healthy.
- Inspect authenticator sessions and RADIUS logs before and after service restoration.
- Test authorized and unauthorized MACs behind the same physical port.
- Review session timers and test role change after reauthentication.
Explanation
Correct Answer
B:Inspect authenticator sessions and RADIUS logs before and after service restoration. This checks whether affected clients transition from fallback to the correct authorized role without stale access.
Incorrect Answers
A:Keep all ports in server-fail mode indefinitely after the server is healthy. That bypass leaves the RADIUS server-fail remediation and reauthentication issue unresolved. Failure to reauthorize after recovery can leave endpoints overprivileged or stuck in fallback.
C:Test authorized and unauthorized MACs behind the same physical port. That check applies chiefly to 802.1X multi-supplicant port control, not the current RADIUS server-fail remediation and reauthentication issue. Server-recovery behavior and authentication session lifecycle affect effective access.
D:Review session timers and test role change after reauthentication. That check applies chiefly to 802.1X periodic reauthentication, not the current RADIUS server-fail remediation and reauthentication issue. Server-recovery behavior and authentication session lifecycle affect effective access.
Question 167
A migrated access switch tags ordinary endpoint frames that expect untagged delivery. Which next investigation or correction is MOST appropriate?
- Validate allowed gateway ping and blocked peer-to-peer Layer 2 paths.
- Change the LLDP system-name to the desired VLAN and assume membership changes.
- Inspect encapsulated control traffic on provider ingress and customer egress.
- Inspect interface mode VLAN members and the learned MAC table.
Explanation
Correct Answer
D:Inspect interface mode VLAN members and the learned MAC table. This checks whether untagged frames enter the correct VLAN and reach only eligible peers.
Incorrect Answers
A:Validate allowed gateway ping and blocked peer-to-peer Layer 2 paths. That check applies chiefly to Private VLAN isolated port separation, not the current Ethernet access interface VLAN membership issue. Access VLAN membership maps untagged endpoint traffic into one logical broadcast domain.
B:Change the LLDP system-name to the desired VLAN and assume membership changes. That bypass leaves the Ethernet access interface VLAN membership issue unresolved. Changing the switch IP address does not correct an endpoint access VLAN mismatch.
C:Inspect encapsulated control traffic on provider ingress and customer egress. That check applies chiefly to L2PT customer BPDU tunneling, not the current Ethernet access interface VLAN membership issue. Access VLAN membership maps untagged endpoint traffic into one logical broadcast domain.
Question 168
Two switches with identical MST instance IDs operate as different MST regions. After deploying the recommended MSTP region name revision and VLAN digest change, which result MOST directly verifies success?
- Eligible ARP lookups are answered locally and unnecessary BUM replication decreases.
- Switches report the same MST region and shared MSTI topology.
- Untagged frames enter the correct VLAN and reach only eligible peers.
- Isolated endpoints reach the intended shared gateway but not peer isolated ports.
Explanation
Correct Answer
B:Switches report the same MST region and shared MSTI topology. This is the directly observable outcome for MSTP region name revision and VLAN digest. MST region identity depends on matching region attributes including VLAN mapping digest.
Incorrect Answers
A:Eligible ARP lookups are answered locally and unnecessary BUM replication decreases. This validates EVPN ARP suppression from IP MAC bindings but does not directly demonstrate the required MSTP region name revision and VLAN digest result. MST region identity depends on matching region attributes including VLAN mapping digest.
C:Untagged frames enter the correct VLAN and reach only eligible peers. This validates Ethernet access interface VLAN membership but does not directly demonstrate the required MSTP region name revision and VLAN digest result. MST region identity depends on matching region attributes including VLAN mapping digest.
D:Isolated endpoints reach the intended shared gateway but not peer isolated ports. This validates Private VLAN isolated port separation but does not directly demonstrate the required MSTP region name revision and VLAN digest result. MST region identity depends on matching region attributes including VLAN mapping digest.
Question 169
An access port times out despite network reachability to the RADIUS server. Select TWO statements that correctly combine the RADIUS Access-Accept versus Access-Reject handling implementation, its evidence, or its governing principle.
- Convert every Access-Reject into anonymous full network access.
- Review authentication policy and RADIUS response attributes with an authorized test identity.
- Access-Accept authorizes approved access while explicit rejections remain denied.
- Configure supported reauthentication or session restoration after AAA recovery.
- Configure a supported multi-supplicant policy with the intended authorization granularity.
Explanation
Correct Answers
B:Review authentication policy and RADIUS response attributes with an authorized test identity. This is the intended implementation action for RADIUS Access-Accept versus Access-Reject handling.
C:Access-Accept authorizes approved access while explicit rejections remain denied. This is direct observable evidence for RADIUS Access-Accept versus Access-Reject handling.
Incorrect Answers
A:Convert every Access-Reject into anonymous full network access. This would not be an appropriate RADIUS Access-Accept versus Access-Reject handling decision. Treating Access-Reject as the same failure as timeout can trigger unsafe fallback behavior.
D:Configure supported reauthentication or session restoration after AAA recovery. This belongs to RADIUS server-fail remediation and reauthentication, not the specified RADIUS Access-Accept versus Access-Reject handling operation. RADIUS outcomes express AAA authorization decisions separate from transport connectivity.
E:Configure a supported multi-supplicant policy with the intended authorization granularity. This belongs to 802.1X multi-supplicant port control, not the specified RADIUS Access-Accept versus Access-Reject handling operation. RADIUS outcomes express AAA authorization decisions separate from transport connectivity.
Question 170
Two area-zero routers on an Ethernet link stay in Init because received Hellos list no reciprocal router ID. Which configuration or operational step BEST meets the stated requirement?
- Apply a guarded OSPFv3 export policy matching the correct inet6 source and prefix.
- Choose an intentional OSPF external metric type and test ASBR reachability assumptions.
- Change only the router ID and claim incompatible timer settings will be ignored.
- Compare Hello packets area ID intervals and neighbor states before changing interface OSPF settings.
Explanation
Correct Answer
D:Compare Hello packets area ID intervals and neighbor states before changing interface OSPF settings. OSPF neighbors exchange compatible Hellos before database synchronization. The expected validation is that a full adjacency forms after bidirectional Hellos and compatible timers are observed.
Incorrect Answers
A:Apply a guarded OSPFv3 export policy matching the correct inet6 source and prefix. This addresses OSPFv3 routing policy for external IPv6 rather than the required OSPFv2 Hello and Dead timer adjacency decision. OSPF neighbors exchange compatible Hellos before database synchronization.
B:Choose an intentional OSPF external metric type and test ASBR reachability assumptions. This addresses OSPF external type-one versus type-two metrics rather than the required OSPFv2 Hello and Dead timer adjacency decision. OSPF neighbors exchange compatible Hellos before database synchronization.
C:Change only the router ID and claim incompatible timer settings will be ignored. This is a risky or ineffective shortcut for OSPFv2 Hello and Dead timer adjacency. Mismatched Hello or Dead intervals block a reliable adjacency.
