Juniper JN0-364 Questions & Answers

This is a useful guard against static route next-hop resolution, but it is not scoped to the observed aggregate route contributor failure. An appropriate test would show that the aggregate is active only with the expected contributors and disappears when the contributor precondition is removed.

Check inter-area prefix availability at each ABR after changes to area boundaries and route filters. That ongoing check is for OSPF area LSA propagation; it would not reliably detect recurrence of aggregate route contributor. An aggregate route is conditional on active contributing routes and normally uses a discard or reject next hop to avoid creating a forwarding loop.

Check forwarding-table next-hop sets and multi-flow traffic after any export-policy or path-cost change. The monitored boundary differs from aggregate route contributor, so the original weakness might reappear unnoticed. An aggregate route is conditional on active contributing routes and normally uses a discard or reject next hop to avoid creating a forwarding loop.

Verify LAN circuit type, DIS election priorities, and pseudonode LSP origin under the planned shared-segment design. Its normal acceptance signal would be the shared LAN shows the intended DIS and pseudonode information, and adjacency remains stable through a controlled election. Here the deciding check is different: external route advertisements show the intended relative AS-path lengths and measured inbound behavior is compared with the goal.

Set and test a coherent MED policy between comparable paths, acknowledging peer AS comparison behavior and upstream policies. Its normal acceptance signal would be comparably eligible paths carry intended MEDs and route selection in the agreed test case follows the planned preference. Here the deciding check is different: external route advertisements show the intended relative AS-path lengths and measured inbound behavior is compared with the goal.

Configure the appropriate EBGP multihop reachability and neighbor addressing, then verify session setup on the intended loopback endpoints. That could help in a case involving EBGP multihop reachability. This failure instead depends on AS-path prepend inbound influence; AS-path prepending can make a path less attractive to other ASes but does not override their local policies or guarantee inbound steering.

Exercise matched and unmatched test flows after changes and monitor the filter counters and selected forwarding table. The monitored boundary differs from equal-cost forwarding flow hashing, so the original weakness might reappear unnoticed. Equal routing candidates do not prove the forwarding engine is using ECMP; Junos load-balancing policy and flow hashing determine installed next hops.

Alert when the required static route becomes hidden or its next hop stops resolving, and validate reachability before committing changes. That ongoing check is for static route next-hop resolution; it would not reliably detect recurrence of equal-cost forwarding flow hashing. Equal routing candidates do not prove the forwarding engine is using ECMP; Junos load-balancing policy and flow hashing determine installed next hops.

The control protects VLAN access trunk distinction. It does not establish the ongoing equal-cost forwarding flow hashing behavior required in this network. Equal routing candidates do not prove the forwarding engine is using ECMP; Junos load-balancing policy and flow hashing determine installed next hops.

Both IPv4 endpoint paths are reachable and IPv6 packets traverse the encapsulated link end to end. It would validate a separate IPv6 over IPv4 tunnel underlay operation, not the change needed here. Confirm instead that the expected OSPFv3 neighbor reaches Full and IPv6 routes appear with intended next hops.

The intended IPv6 destination has an active route with a resolved next hop and working egress interface. That establishes IPv6 static next-hop scope rather than a repaired OSPFv3 IPv6 neighbor reachability path. The reported failure still requires this evidence: the expected OSPFv3 neighbor reaches Full and IPv6 routes appear with intended next hops.

The check is meaningful for MPLS label push swap pop, but it does not prove that OSPFv3 IPv6 neighbor reachability was repaired. OSPFv3 provides OSPF routing for IPv6; successful IPv4 OSPFv2 peering does not establish an IPv6 adjacency.

Validate MST digest and instance mapping consistency as part of configuration review. That ongoing check is for MSTP region consistency; it would not reliably detect recurrence of MPLS label push swap pop. MPLS forwards using labels: ingress commonly pushes labels, intermediate LSRs swap them, and the egress removes the remaining label.

Alert on missing LDP label mappings for required FECs after peer resets and topology changes. That ongoing check is for LDP label binding completeness; it would not reliably detect recurrence of MPLS label push swap pop. MPLS forwards using labels: ingress commonly pushes labels, intermediate LSRs swap them, and the egress removes the remaining label. Applied here, the relevant facts are: A provider ingress forwards customer traffic as ordinary IP despite the path requiring MPLS label imposition. The question asks which ongoing control would most directly detect or prevent the same failure from recurring.

This is a useful guard against RSVP path bandwidth admission, but it is not scoped to the observed MPLS label push swap pop failure. An appropriate test would show that packet traces or label forwarding entries show the planned push, swap, and pop sequence across the path.

The control protects segment routing adjacency SID. It does not establish the ongoing MPLS label forwarding table mismatch behavior required in this network. Control-plane LSP state and data-plane label forwarding entries are separate checks; an Up session does not prove the FIB is correct.

This is a useful guard against MAC address learning and moves, but it is not scoped to the observed MPLS label forwarding table mismatch failure. An appropriate test would show that incoming labels resolve to valid outgoing label operations and interfaces, and data-plane counters show successful forwarding.

The control protects MPLS label stack bottom bit. It does not establish the ongoing MPLS label forwarding table mismatch behavior required in this network. Control-plane LSP state and data-plane label forwarding entries are separate checks; an Up session does not prove the FIB is correct.

The check is meaningful for MPLS label forwarding table mismatch, but it does not prove that BGP import export control was repaired. BGP import policy governs received routes and export policy governs outbound advertisements; changing the wrong direction cannot enforce the intended boundary.

The intended multi-hop peer establishes while IP reachability and any required loopback-source configuration are correct. It would validate a separate EBGP multihop reachability operation, not the change needed here. Confirm instead that only approved prefixes are advertised to or accepted from the intended neighbor, as confirmed by received and advertised route views.

The peer moves to Established with the agreed local and remote AS values and appropriate session messages. It would validate a separate BGP ASN and OPEN negotiation operation, not the change needed here. Confirm instead that only approved prefixes are advertised to or accepted from the intended neighbor, as confirmed by received and advertised route views.

Enable appropriate LDP interface discovery and verify discovery hellos and eventual neighbor session state. Its normal acceptance signal would be the intended interface discovers the peer and the LDP neighbor appears with an operational session. Here the deciding check is different: the prefix SID is advertised and all ingress routers compute consistent transport label behavior for the node destination.

The proposal changes RSVP PATH and RESV signaling; that is not the failure isolated by the facts. It could leave segment routing prefix SID unresolved even if its own test passed. SR-MPLS prefix SIDs and the segment routing global block provide IGP-signaled reachability without relying on LDP for each FEC.

Build a narrowly scoped IS-IS export policy that matches approved active prefixes and verify received advertisements. That could help in a case involving IS-IS route redistribution policy. This failure instead depends on segment routing prefix SID; SR-MPLS prefix SIDs and the segment routing global block provide IGP-signaled reachability without relying on LDP for each FEC.

Although IS-IS wide metrics needs this consideration, the failure at issue has a different cause. OSPF broadcast networks elect a DR and BDR; raising priority does not automatically preempt an already elected DR.

Although OSPF point-to-point topology needs this consideration, the failure at issue has a different cause. OSPF broadcast networks elect a DR and BDR; raising priority does not automatically preempt an already elected DR.

This principle matters when troubleshooting OSPF area LSA propagation, but using it here mistakes a different failure mode for OSPF designated router election. The relevant distinction is: OSPF broadcast networks elect a DR and BDR; raising priority does not automatically preempt an already elected DR.

Correct the static route's reachable next hop and preference, then verify that its active route resolves to an operational forwarding interface. That could help in a case involving static route next-hop resolution. This failure instead depends on filter-based forwarding table selection; filter-based forwarding selects a routing lookup table using packet classification; it does not rewrite the global best route for every packet.

Treat the reserved or martian prefix as invalid for production routing and correct the source instead of overriding safety rejection blindly. This addresses martian source address rejection, but the reported symptoms arise from filter-based forwarding table selection. For this case, verify instead that only the selected traffic uses the inspection forwarding table while unmatched traffic follows the ordinary destination route.

The proposal changes IS-IS LAN designated intermediate system; that is not the failure isolated by the facts. It could leave filter-based forwarding table selection unresolved even if its own test passed. Filter-based forwarding selects a routing lookup table using packet classification; it does not rewrite the global best route for every packet.

This principle matters when troubleshooting IS-IS wide metrics, but using it here mistakes a different failure mode for IS-IS adjacency circuit level. The relevant distinction is: IS-IS peers must support a common adjacency level; active Ethernet transport does not compensate for a level mismatch.

IS-IS LSP sequencing and sequence-number PDUs keep link-state databases synchronized; adjacency status alone does not ensure database parity. Those conditions do not account for the specific IS-IS adjacency circuit level problem reported by Coppercrest Cloud.

OSPF neighbor formation requires compatible hello and dead timers; link-layer carrier does not override timer mismatch. That describes OSPF hello and dead timers, whereas the observed symptoms are caused by IS-IS adjacency circuit level; it does not predict the reported behavior.