Juniper JN0-650 Practice Test 53
Question 520
A broad Layer 2 tunnel unexpectedly carries provider-facing LLDP messages to a customer. Which technical principle BEST explains the L2PT protocol selection and isolation decision?
- MVRP learned registrations have different lifecycle from explicitly configured static VLAN memberships.
- Multifield classification can use packet fields beyond preexisting DSCP markings.
- L2PT encapsulates selected customer Layer 2 control frames across a provider domain.
- L2PT should scope control-protocol tunneling to intended customer Ethernet boundaries.
Explanation
Correct Answer
D:L2PT should scope control-protocol tunneling to intended customer Ethernet boundaries. In this situation, the relevant action is to select explicitly supported customer protocols and enforce L2PT boundaries.
Incorrect Answers
A:MVRP learned registrations have different lifecycle from explicitly configured static VLAN memberships. That principle is related to MVRP static versus dynamic registration, not the main L2PT protocol selection and isolation choice. Overbroad tunneling may couple independent customer and provider control planes.
B:Multifield classification can use packet fields beyond preexisting DSCP markings. That principle is related to Junos multifield firewall filter classification, not the main L2PT protocol selection and isolation choice. Overbroad tunneling may couple independent customer and provider control planes.
C:L2PT encapsulates selected customer Layer 2 control frames across a provider domain. That principle is related to L2PT customer BPDU tunneling, not the main L2PT protocol selection and isolation choice. Overbroad tunneling may couple independent customer and provider control planes.
Question 521
During an operational risk review, this situation is reported: A PIM neighbor receives group joins from an unapproved network segment. If the underlying control is neglected, which failure would MOST directly follow?
- An unrestricted policy can carry sensitive multicast into unintended domains.
- Treating IGMP as an interrouter PIM replacement prevents routed multicast delivery.
- Placing critical admin endpoints behind MAC-only authentication permits spoofing risk.
- Missing membership state or wrong querier behavior can flood or blackhole multicast.
Explanation
Correct Answer
A:An unrestricted policy can carry sensitive multicast into unintended domains. Multicast routing policy or scoping constrains distribution without changing sender addresses. A useful corrective investigation is to verify denied-group counters and successful forwarding for approved test groups.
Incorrect Answers
B:Treating IGMP as an interrouter PIM replacement prevents routed multicast delivery. This is a IGMPv2 membership report and leave failure pattern, not the primary Multicast policy group scoping failure in this case. Multicast routing policy or scoping constrains distribution without changing sender addresses.
C:Placing critical admin endpoints behind MAC-only authentication permits spoofing risk. This is a MAC RADIUS spoofing limitations failure pattern, not the primary Multicast policy group scoping failure in this case. Multicast routing policy or scoping constrains distribution without changing sender addresses.
D:Missing membership state or wrong querier behavior can flood or blackhole multicast. This is a IGMP snooping access-port replication failure pattern, not the primary Multicast policy group scoping failure in this case. Multicast routing policy or scoping constrains distribution without changing sender addresses.
Question 522
A switch port still uses default queues after a custom scheduler map is created. Select THREE statements that correctly combine the Scheduler maps attached to egress interface implementation, its evidence, or its governing principle.
- Apply the intended scheduler map to the actual output interface.
- Classify or remark untrusted edge traffic while retaining appropriate trusted phone service.
- Configure suitable RED or WRED drop profiles and map PLP to planned thresholds.
- Scheduler maps associate forwarding classes with schedulers and require interface application.
- Add a scheduler-map description and assume the policy reaches all interfaces globally.
- Egress queue behavior follows the scheduler-map settings during representative load.
Explanation
Correct Answers
A:Apply the intended scheduler map to the actual output interface. This is the intended implementation action for Scheduler maps attached to egress interface.
D:Scheduler maps associate forwarding classes with schedulers and require interface application. It explains the action and observed outcome for Scheduler maps attached to egress interface.
F:Egress queue behavior follows the scheduler-map settings during representative load. This is direct observable evidence for Scheduler maps attached to egress interface.
Incorrect Answers
B:Classify or remark untrusted edge traffic while retaining appropriate trusted phone service. This belongs to QoS trust boundary at campus edge, not the specified Scheduler maps attached to egress interface operation. Scheduler maps associate forwarding classes with schedulers and require interface application.
C:Configure suitable RED or WRED drop profiles and map PLP to planned thresholds. This belongs to RED WRED drop profile thresholds, not the specified Scheduler maps attached to egress interface operation. Scheduler maps associate forwarding classes with schedulers and require interface application.
E:Add a scheduler-map description and assume the policy reaches all interfaces globally. This would not be an appropriate Scheduler maps attached to egress interface decision. An unattached scheduler map has no effect on the live bottleneck port.
Question 523
Multicast for an internal finance group must not leave a specified campus boundary. Which configuration or operational step BEST meets the stated requirement?
- Apply scoped multicast policy restricting eligible groups at the proper boundary.
- Verify PIM sparse-mode SPT switch behavior and source-specific forwarding entries.
- Enable compatible PIM on intended routed interfaces and verify neighbor discovery.
- Rename the multicast group InternalOnly and assume routers automatically enforce a security boundary.
Explanation
Correct Answer
A:Apply scoped multicast policy restricting eligible groups at the proper boundary. Multicast routing policy or scoping constrains distribution without changing sender addresses. The expected validation is that authorized groups forward while disallowed group joins or advertisements are rejected.
Incorrect Answers
B:Verify PIM sparse-mode SPT switch behavior and source-specific forwarding entries. This addresses ASM shared tree versus SPT switchover rather than the required Multicast policy group scoping decision. Multicast routing policy or scoping constrains distribution without changing sender addresses.
C:Enable compatible PIM on intended routed interfaces and verify neighbor discovery. This addresses PIM sparse-mode neighbor discovery rather than the required Multicast policy group scoping decision. Multicast routing policy or scoping constrains distribution without changing sender addresses.
D:Rename the multicast group InternalOnly and assume routers automatically enforce a security boundary. This is a risky or ineffective shortcut for Multicast policy group scoping. An unrestricted policy can carry sensitive multicast into unintended domains.
Question 524
During an operational risk review, this situation is reported: A switch has scheduler maps configured yet the intended forwarding class uses the default queue. If the underlying control is neglected, which failure would MOST directly follow?
- Naming a class Voice without mapping it does not guarantee queue scheduling.
- Leaving roots uncontrolled may put access switches in core transit roles.
- Inspecting only a configured class name can hide actual drops and misclassification.
- Incorrect ingress mapping sends high-priority traffic to default queues.
Explanation
Correct Answer
A:Naming a class Voice without mapping it does not guarantee queue scheduling. Forwarding classes express per-hop traffic treatment and map to transmission queues. A useful corrective investigation is to inspect class-to-queue association and per-queue statistics.
Incorrect Answers
B:Leaving roots uncontrolled may put access switches in core transit roles. This is a MSTP instance root selection failure pattern, not the primary Junos forwarding class to queue mapping failure in this case. Forwarding classes express per-hop traffic treatment and map to transmission queues.
C:Inspecting only a configured class name can hide actual drops and misclassification. This is a CoS end-to-end verification of drop behavior failure pattern, not the primary Junos forwarding class to queue mapping failure in this case. Forwarding classes express per-hop traffic treatment and map to transmission queues.
D:Incorrect ingress mapping sends high-priority traffic to default queues. This is a Junos ingress BA DSCP classifier failure pattern, not the primary Junos forwarding class to queue mapping failure in this case. Forwarding classes express per-hop traffic treatment and map to transmission queues.
Question 525
Two enterprise WAN exits receive equally specific destinations but primary egress should be favored. Which configuration or operational step BEST meets the stated requirement?
- Examine and apply origin attribute handling only within an intentional routing-policy decision.
- Apply supported BGP accepted-prefix limits and operational alerts.
- Advertise a larger MED to the upstream and assume all local speakers raise LOCAL_PREF.
- Set a policy-based higher local preference for preferred internal BGP paths.
Explanation
Correct Answer
D:Set a policy-based higher local preference for preferred internal BGP paths. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection. The expected validation is that enterprise routers prefer approved primary exit while allowing backup on withdrawal.
Incorrect Answers
A:Examine and apply origin attribute handling only within an intentional routing-policy decision. This addresses BGP origin attribute influence rather than the required BGP LOCAL_PREF outbound exit selection decision. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection.
B:Apply supported BGP accepted-prefix limits and operational alerts. This addresses BGP prefix-limit peer protection rather than the required BGP LOCAL_PREF outbound exit selection decision. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection.
C:Advertise a larger MED to the upstream and assume all local speakers raise LOCAL_PREF. This is a risky or ineffective shortcut for BGP LOCAL_PREF outbound exit selection. Treating MED as a replacement for internal LOCAL_PREF can select the wrong exit.
Question 526
An internal failover sends outbound traffic through the wrong ISP despite healthy iBGP. Select TWO statements that correctly combine the BGP LOCAL_PREF outbound exit selection implementation, its evidence, or its governing principle.
- Set a policy-based higher local preference for preferred internal BGP paths.
- Enterprise routers prefer approved primary exit while allowing backup on withdrawal.
- Apply controlled AS_PATH prepending in export policy to appropriate external neighbors.
- Advertise a larger MED to the upstream and assume all local speakers raise LOCAL_PREF.
- Configure supported route reflector clients and cluster identifiers with loop safeguards.
Explanation
Correct Answers
A:Set a policy-based higher local preference for preferred internal BGP paths. This is the intended implementation action for BGP LOCAL_PREF outbound exit selection.
B:Enterprise routers prefer approved primary exit while allowing backup on withdrawal. This is direct observable evidence for BGP LOCAL_PREF outbound exit selection.
Incorrect Answers
C:Apply controlled AS_PATH prepending in export policy to appropriate external neighbors. This belongs to BGP AS path prepend outbound advertisement, not the specified BGP LOCAL_PREF outbound exit selection operation. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection.
D:Advertise a larger MED to the upstream and assume all local speakers raise LOCAL_PREF. This would not be an appropriate BGP LOCAL_PREF outbound exit selection decision. Treating MED as a replacement for internal LOCAL_PREF can select the wrong exit.
E:Configure supported route reflector clients and cluster identifiers with loop safeguards. This belongs to BGP route reflection cluster, not the specified BGP LOCAL_PREF outbound exit selection operation. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection.
Question 527
Routes arrive with an approved service community and several unintended inherited tags. After deploying the recommended BGP communities match and deletion change, which result MOST directly verifies success?
- Outgoing routes retain required communities without leaking internal-only tag values.
- BGP reaches Established with the expected local and remote ASN and prefix families.
- The handset receives voice VLAN policy and tags voice frames as intended.
- Excessive routes trigger the intended protection without destabilizing unrelated sessions.
Explanation
Correct Answer
A:Outgoing routes retain required communities without leaking internal-only tag values. This is the directly observable outcome for BGP communities match and deletion. Communities can be selectively matched manipulated and stripped in routing policy.
Incorrect Answers
B:BGP reaches Established with the expected local and remote ASN and prefix families. This validates BGP eBGP peer AS and local identity but does not directly demonstrate the required BGP communities match and deletion result. Communities can be selectively matched manipulated and stripped in routing policy.
C:The handset receives voice VLAN policy and tags voice frames as intended. This validates LLDP-MED voice network policy but does not directly demonstrate the required BGP communities match and deletion result. Communities can be selectively matched manipulated and stripped in routing policy.
D:Excessive routes trigger the intended protection without destabilizing unrelated sessions. This validates BGP prefix-limit peer protection but does not directly demonstrate the required BGP communities match and deletion result. Communities can be selectively matched manipulated and stripped in routing policy.
Question 528
An IP phone with a downstream computer must keep voice and workstation traffic in different VLANs. After deploying the recommended Voice VLAN tagged versus PC data traffic change, which result MOST directly verifies success?
- Phone RTP and signaling reach voice network while PC traffic stays in data segment.
- Expected adjacency relationships achieve correct state for the selected network type.
- The switch and phone discover each other with accurate system and port details.
- The handset receives voice VLAN policy and tags voice frames as intended.
Explanation
Correct Answer
A:Phone RTP and signaling reach voice network while PC traffic stays in data segment. This is the directly observable outcome for Voice VLAN tagged versus PC data traffic. Phone access-port design can carry tagged voice and untagged data for separate policies.
Incorrect Answers
B:Expected adjacency relationships achieve correct state for the selected network type. This validates OSPF neighbor state troubleshooting workflow but does not directly demonstrate the required Voice VLAN tagged versus PC data traffic result. Phone access-port design can carry tagged voice and untagged data for separate policies.
C:The switch and phone discover each other with accurate system and port details. This validates LLDP neighbor advertisement but does not directly demonstrate the required Voice VLAN tagged versus PC data traffic result. Phone access-port design can carry tagged voice and untagged data for separate policies.
D:The handset receives voice VLAN policy and tags voice frames as intended. This validates LLDP-MED voice network policy but does not directly demonstrate the required Voice VLAN tagged versus PC data traffic result. Phone access-port design can carry tagged voice and untagged data for separate policies.
Question 529
An application must send IPv6 multicast updates only within its link-local scope. Which configuration or operational step BEST meets the stated requirement?
- Select appropriate IPv6 multicast addressing and scope behavior for intended receivers.
- Align source reachability and any approved multicast RPF policy with actual topology.
- Configure 239.255.0.1 as an IPv6 multicast group and claim syntax is interoperable.
- Verify PIM sparse-mode SPT switch behavior and source-specific forwarding entries.
Explanation
Correct Answer
A:Select appropriate IPv6 multicast addressing and scope behavior for intended receivers. IPv6 multicast uses ff00::/8 scoped addressing separate from IPv4 group syntax. The expected validation is that packets remain inside the permitted IPv6 scope and group memberships reflect the destination.
Incorrect Answers
B:Align source reachability and any approved multicast RPF policy with actual topology. This addresses Multicast source route policy and RPF rather than the required IPv6 multicast scope and group use decision. IPv6 multicast uses ff00::/8 scoped addressing separate from IPv4 group syntax.
C:Configure 239.255.0.1 as an IPv6 multicast group and claim syntax is interoperable. This is a risky or ineffective shortcut for IPv6 multicast scope and group use. Mis-scoped multicast can leak too far or fail to reach authorized hosts.
D:Verify PIM sparse-mode SPT switch behavior and source-specific forwarding entries. This addresses ASM shared tree versus SPT switchover rather than the required IPv6 multicast scope and group use decision. IPv6 multicast uses ff00::/8 scoped addressing separate from IPv4 group syntax.
Question 530
A Junos eBGP session remains Active because each router expects the wrong remote autonomous system. After deploying the recommended BGP eBGP peer AS and local identity change, which result MOST directly verifies success?
- Received and advertised route sets satisfy their separate intended controls.
- Multiple eligible next hops are installed and traffic follows approved ECMP hashing.
- BGP reaches Established with the expected local and remote ASN and prefix families.
- The stub receives an appropriate default or interarea reachability without external type-5 flooding.
Explanation
Correct Answer
C:BGP reaches Established with the expected local and remote ASN and prefix families. This is the directly observable outcome for BGP eBGP peer AS and local identity. BGP OPEN exchange checks autonomous-system identity and capability compatibility.
Incorrect Answers
A:Received and advertised route sets satisfy their separate intended controls. This validates BGP import versus export policy direction but does not directly demonstrate the required BGP eBGP peer AS and local identity result. BGP OPEN exchange checks autonomous-system identity and capability compatibility.
B:Multiple eligible next hops are installed and traffic follows approved ECMP hashing. This validates BGP multipath equal-cost path installation but does not directly demonstrate the required BGP eBGP peer AS and local identity result. BGP OPEN exchange checks autonomous-system identity and capability compatibility.
D:The stub receives an appropriate default or interarea reachability without external type-5 flooding. This validates OSPF stub area external LSA suppression but does not directly demonstrate the required BGP eBGP peer AS and local identity result. BGP OPEN exchange checks autonomous-system identity and capability compatibility.
