Juniper JN0-650 Practice Test 33
Question 320
Two enterprise WAN exits receive equally specific destinations but primary egress should be favored. After deploying the recommended BGP LOCAL_PREF outbound exit selection change, which result MOST directly verifies success?
- Flapping prefixes are damped according to intended thresholds and recover within acceptable time.
- Enterprise routers prefer approved primary exit while allowing backup on withdrawal.
- The upstream accepts advertised MED values with understood decision constraints.
- Untagged frames enter the correct VLAN and reach only eligible peers.
Explanation
Correct Answer
B:Enterprise routers prefer approved primary exit while allowing backup on withdrawal. This is the directly observable outcome for BGP LOCAL_PREF outbound exit selection. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection.
Incorrect Answers
A: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 BGP LOCAL_PREF outbound exit selection result. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection.
C:The upstream accepts advertised MED values with understood decision constraints. This validates BGP MED inbound traffic hint but does not directly demonstrate the required BGP LOCAL_PREF outbound exit selection result. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection.
D: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 BGP LOCAL_PREF outbound exit selection result. LOCAL_PREF is propagated within an AS and commonly steers outbound path selection.
Question 321
A team expects BGP path selection to decide between routes learned from separate protocols. Which technical principle BEST explains the BGP route preference versus OSPF decision?
- Junos route selection between protocols is not the same as BGP best-path selection.
- Route damping suppresses unstable routes but adds recovery latency.
- BGP relies on TCP transport and does not form merely because IP reachability exists.
- Two-Way may be normal between DROther neighbors while Exchange stuck indicates database issues.
Explanation
Correct Answer
A:Junos route selection between protocols is not the same as BGP best-path selection. In this situation, the relevant action is to compare Junos route preference across protocols separately from intraprotocol BGP attributes.
Incorrect Answers
B:Route damping suppresses unstable routes but adds recovery latency. That principle is related to BGP route damping flap penalty, not the main BGP route preference versus OSPF choice. Confusing local preference with Junos route preference can produce wrong active-route reasoning.
C:BGP relies on TCP transport and does not form merely because IP reachability exists. That principle is related to BGP TCP 179 and firewall reachability, not the main BGP route preference versus OSPF choice. Confusing local preference with Junos route preference can produce wrong active-route reasoning.
D:Two-Way may be normal between DROther neighbors while Exchange stuck indicates database issues. That principle is related to OSPF neighbor state troubleshooting workflow, not the main BGP route preference versus OSPF choice. Confusing local preference with Junos route preference can produce wrong active-route reasoning.
Question 322
A distribution port blocks when superior BPDUs arrive from a downstream access switch. Which next investigation or correction is MOST appropriate?
- Inspect MST configuration digest region and per-instance port roles.
- Test communication matrix among each community and shared gateway.
- Inspect root-protection state and spanning-tree topology events.
- Configure a lower route preference in inet.0 and assume STP root cannot change.
Explanation
Correct Answer
C:Inspect root-protection state and spanning-tree topology events. This checks whether downstream superior BPDUs are rejected while the intended root remains authoritative.
Incorrect Answers
A:Inspect MST configuration digest region and per-instance port roles. That check applies chiefly to MSTP region name revision and VLAN digest, not the current Root protection on designated links issue. Root protection guards designated bridge roles against unexpected root changes.
B:Test communication matrix among each community and shared gateway. That check applies chiefly to Private VLAN community and promiscuous roles, not the current Root protection on designated links issue. Root protection guards designated bridge roles against unexpected root changes.
D:Configure a lower route preference in inet.0 and assume STP root cannot change. That bypass leaves the Root protection on designated links issue unresolved. Allowing untrusted access switches to become STP root can shift and disrupt network paths.
Question 323
A Junos route shows one best path while ECMP traffic sharing was expected. Select TWO statements that correctly combine the BGP multipath equal-cost path installation implementation, its evidence, or its governing principle.
- Apply a scoped BGP next-hop-self or next-hop resolution design at the appropriate edge.
- Compare Junos route preference across protocols separately from intraprotocol BGP attributes.
- Enable compatible BGP multipath and forwarding-table load balancing where justified.
- Multiple eligible next hops are installed and traffic follows approved ECMP hashing.
- Set two interfaces to identical descriptions and assume the forwarding table hashes across both.
Explanation
Correct Answers
C:Enable compatible BGP multipath and forwarding-table load balancing where justified. This is the intended implementation action for BGP multipath equal-cost path installation.
D:Multiple eligible next hops are installed and traffic follows approved ECMP hashing. This is direct observable evidence for BGP multipath equal-cost path installation.
Incorrect Answers
A:Apply a scoped BGP next-hop-self or next-hop resolution design at the appropriate edge. This belongs to iBGP next-hop-self on edge, not the specified BGP multipath equal-cost path installation operation. BGP multipath requires compatible path properties and FIB programming beyond two received advertisements.
B:Compare Junos route preference across protocols separately from intraprotocol BGP attributes. This belongs to BGP route preference versus OSPF, not the specified BGP multipath equal-cost path installation operation. BGP multipath requires compatible path properties and FIB programming beyond two received advertisements.
E:Set two interfaces to identical descriptions and assume the forwarding table hashes across both. This would not be an appropriate BGP multipath equal-cost path installation decision. Merely seeing multiple BGP routes does not prove load balancing occurs.
Question 324
A new Q-in-Q link passes one customer service but another fails at an intermediate device. Which configuration or operational step BEST meets the stated requirement?
- Configure correct trunk mode VLAN membership and tagging at both switch interfaces.
- Trace each Layer 2 hop for VLAN membership tagging outer and inner tags and protection state.
- Globally disable all spanning-tree and VLAN filters to make one service appear reachable.
- Configure compatible Multiple VLAN Registration Protocol operation on supported links.
Explanation
Correct Answer
B:Trace each Layer 2 hop for VLAN membership tagging outer and inner tags and protection state. VLAN delivery requires consistent port roles tags and eligible forwarding state at every hop. The expected validation is that end-to-end captures preserve intended VLAN identity and forwarding without unapproved leakage.
Incorrect Answers
A:Configure correct trunk mode VLAN membership and tagging at both switch interfaces. This addresses 802.1Q trunk allowed VLANs rather than the required Layer 2 trunk VLAN mismatch diagnosis decision. VLAN delivery requires consistent port roles tags and eligible forwarding state at every hop.
C:Globally disable all spanning-tree and VLAN filters to make one service appear reachable. This is a risky or ineffective shortcut for Layer 2 trunk VLAN mismatch diagnosis. Troubleshooting only end-host IP routes can miss a transport VLAN mismatch.
D:Configure compatible Multiple VLAN Registration Protocol operation on supported links. This addresses MVRP dynamic VLAN registration rather than the required Layer 2 trunk VLAN mismatch diagnosis decision. VLAN delivery requires consistent port roles tags and eligible forwarding state at every hop.
Question 325
A snooping switch has no valid querier or membership state and ages out port membership. Which next investigation or correction is MOST appropriate?
- Replace IGMP snooping with BGP prefix aggregation to control Layer 2 ports.
- Compare RP mappings group ranges and route to RP across nodes.
- Inspect show msdp peer and source-active caches for known sources.
- Compare snooping tables and mirrored traffic on subscribed and unsubscribed ports.
Explanation
Correct Answer
D:Compare snooping tables and mirrored traffic on subscribed and unsubscribed ports. This checks whether multicast frames reach receiver ports instead of every port by default.
Incorrect Answers
A:Replace IGMP snooping with BGP prefix aggregation to control Layer 2 ports. That bypass leaves the IGMP snooping access-port replication issue unresolved. Missing membership state or wrong querier behavior can flood or blackhole multicast.
B:Compare RP mappings group ranges and route to RP across nodes. That check applies chiefly to Static RP mapping group range, not the current IGMP snooping access-port replication issue. IGMP snooping uses observed host joins to constrain layer-2 multicast replication.
C:Inspect show msdp peer and source-active caches for known sources. That check applies chiefly to MSDP source active exchange, not the current IGMP snooping access-port replication issue. IGMP snooping uses observed host joins to constrain layer-2 multicast replication.
Question 326
During an operational risk review, this situation is reported: A network upgrade leaves old reference bandwidth values across Junos routing domains. If the underlying control is neglected, which failure would MOST directly follow?
- Inconsistent reference bandwidth across routers may distort intended route decisions.
- Global IPv6 addressing alone does not guarantee OSPFv3 routing.
- Excessive stale retention after a genuine failure can blackhole traffic.
- Invalid keys or incompatible authentication configuration silently discard adjacencies.
Explanation
Correct Answer
A:Inconsistent reference bandwidth across routers may distort intended route decisions. OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster. A useful corrective investigation is to inspect calculated OSPF metrics for representative 10-Gbps and 100-Gbps links.
Incorrect Answers
B:Global IPv6 addressing alone does not guarantee OSPFv3 routing. This is a OSPFv3 IPv6 link-local neighbor formation failure pattern, not the primary OSPF reference bandwidth and high-speed links failure in this case. OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster.
C:Excessive stale retention after a genuine failure can blackhole traffic. This is a BGP graceful restart session continuity failure pattern, not the primary OSPF reference bandwidth and high-speed links failure in this case. OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster.
D:Invalid keys or incompatible authentication configuration silently discard adjacencies. This is a OSPF authentication key or algorithm failure pattern, not the primary OSPF reference bandwidth and high-speed links failure in this case. OSPF automatic cost can require reference-bandwidth adjustment as interfaces become faster.
Question 327
Legacy printers cannot run an 802.1X supplicant but require controlled admission. After deploying the recommended MAC RADIUS printer onboarding change, which result MOST directly verifies success?
- Captures and counters explain ingress class egress queue and final header marking.
- Authorized user EAP exchanges complete while invalid or expired certificates are rejected.
- Guests receive only allowed connectivity and protected subnets stay unreachable.
- Registered printers receive limited required access while unknown MACs are rejected.
Explanation
Correct Answer
D:Registered printers receive limited required access while unknown MACs are rejected. This is the directly observable outcome for MAC RADIUS printer onboarding. MAC RADIUS can authorize nonsupplicant devices but MAC identity is easier to spoof.
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 MAC RADIUS printer onboarding result. MAC RADIUS can authorize nonsupplicant devices but MAC identity is easier to spoof.
B:Authorized user EAP exchanges complete while invalid or expired certificates are rejected. This validates 802.1X EAP authentication credential validation but does not directly demonstrate the required MAC RADIUS printer onboarding result. MAC RADIUS can authorize nonsupplicant devices but MAC identity is easier to spoof.
C:Guests receive only allowed connectivity and protected subnets stay unreachable. This validates Guest VLAN for unauthenticated clients but does not directly demonstrate the required MAC RADIUS printer onboarding result. MAC RADIUS can authorize nonsupplicant devices but MAC identity is easier to spoof.
Question 328
An IPv6 passive interface must be advertised without forming unwanted neighbors. Which technical principle BEST explains the OSPFv3 IPv6 prefix advertisement decision?
- OSPF E1 includes internal cost to ASBR whereas E2 comparison primarily uses external metric.
- OSPFv3 separates neighbor topology information from IPv6 prefix dissemination.
- OSPF interarea summarization originates at area boundaries with reachability tradeoffs.
- Guest VLAN authorizes limited access for eligible unauthenticated clients.
Explanation
Correct Answer
B:OSPFv3 separates neighbor topology information from IPv6 prefix dissemination. In this situation, the relevant action is to verify IPv6 interface participation and OSPFv3 prefix advertisement settings.
Incorrect Answers
A:OSPF E1 includes internal cost to ASBR whereas E2 comparison primarily uses external metric. That principle is related to OSPF external type-one versus type-two metrics, not the main OSPFv3 IPv6 prefix advertisement choice. An established IPv6 adjacency does not prove every attached prefix is advertised.
C:OSPF interarea summarization originates at area boundaries with reachability tradeoffs. That principle is related to OSPF interarea route summarization, not the main OSPFv3 IPv6 prefix advertisement choice. An established IPv6 adjacency does not prove every attached prefix is advertised.
D:Guest VLAN authorizes limited access for eligible unauthenticated clients. That principle is related to Guest VLAN for unauthenticated clients, not the main OSPFv3 IPv6 prefix advertisement choice. An established IPv6 adjacency does not prove every attached prefix is advertised.
Question 329
A firewall static route must be advertised from an ASBR into OSPF. Which configuration or operational step BEST meets the stated requirement?
- Configure matching supported OSPF authentication parameters on both neighbors.
- Attach an explicit OSPF export policy matching only approved active source routes.
- Configure an interface description containing export and assume it becomes a routing policy.
- Verify IPv6 interface participation and OSPFv3 prefix advertisement settings.
Explanation
Correct Answer
B:Attach an explicit OSPF export policy matching only approved active source routes. Junos OSPF export policies govern which eligible routes enter OSPF as externals. The expected validation is that neighbors learn intended external LSAs without importing restricted management networks.
Incorrect Answers
A:Configure matching supported OSPF authentication parameters on both neighbors. This addresses OSPF authentication key or algorithm rather than the required OSPF external export policy redistribution decision. Junos OSPF export policies govern which eligible routes enter OSPF as externals.
C:Configure an interface description containing export and assume it becomes a routing policy. This is a risky or ineffective shortcut for OSPF external export policy redistribution. An overly permissive export can leak private or unreachable prefixes across the domain.
D:Verify IPv6 interface participation and OSPFv3 prefix advertisement settings. This addresses OSPFv3 IPv6 prefix advertisement rather than the required OSPF external export policy redistribution decision. Junos OSPF export policies govern which eligible routes enter OSPF as externals.
Question 330
A migrated access switch tags ordinary endpoint frames that expect untagged delivery. Select TWO statements that correctly combine the Ethernet access interface VLAN membership implementation, its evidence, or its governing principle.
- Untagged frames enter the correct VLAN and reach only eligible peers.
- Configure compatible Multiple VLAN Registration Protocol operation on supported links.
- Change the LLDP system-name to the desired VLAN and assume membership changes.
- Apply BPDU protection to appropriate edge ports and document recovery.
- Set supported access interface VLAN membership for the intended user segment.
Explanation
Correct Answers
A:Untagged frames enter the correct VLAN and reach only eligible peers. This is direct observable evidence for Ethernet access interface VLAN membership.
E:Set supported access interface VLAN membership for the intended user segment. This is the intended implementation action for Ethernet access interface VLAN membership.
Incorrect Answers
B:Configure compatible Multiple VLAN Registration Protocol operation on supported links. This belongs to MVRP dynamic VLAN registration, not the specified Ethernet access interface VLAN membership operation. Access VLAN membership maps untagged endpoint traffic into one logical broadcast domain.
C:Change the LLDP system-name to the desired VLAN and assume membership changes. This would not be an appropriate Ethernet access interface VLAN membership decision. Changing the switch IP address does not correct an endpoint access VLAN mismatch.
D:Apply BPDU protection to appropriate edge ports and document recovery. This belongs to BPDU protection on access edges, not the specified Ethernet access interface VLAN membership operation. Access VLAN membership maps untagged endpoint traffic into one logical broadcast domain.
