Juniper JN0-364 Questions & Answers

BGP import policy governs received routes and export policy governs outbound advertisements; changing the wrong direction cannot enforce the intended boundary. Those conditions do not account for the specific OSPF interface metric selection problem reported by Beacon Data Exchange.

Although OSPF point-to-point topology needs this consideration, the failure at issue has a different cause. OSPF chooses lowest-cost paths computed from link-state topology; a Full adjacency alone does not guarantee the desired route preference.

This principle matters when troubleshooting OSPF area LSA propagation, but using it here mistakes a different failure mode for OSPF interface metric selection. The relevant distinction is: OSPF chooses lowest-cost paths computed from link-state topology; a Full adjacency alone does not guarantee the desired route preference.

The control protects GRE recursive route avoidance. It does not establish the ongoing GRE endpoint underlay routing behavior required in this network. GRE encapsulates packets between outer IP endpoints; the underlay must route the outer destination before inner traffic can succeed.

Test tunnel path MTU and fragmentation behavior with realistic payload sizes after transport changes. The monitored boundary differs from GRE endpoint underlay routing, so the original weakness might reappear unnoticed. GRE encapsulates packets between outer IP endpoints; the underlay must route the outer destination before inner traffic can succeed.

The control protects BGP communities and routing policy. It does not establish the ongoing GRE endpoint underlay routing behavior required in this network. GRE encapsulates packets between outer IP endpoints; the underlay must route the outer destination before inner traffic can succeed.

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: only approved prefixes are advertised to or accepted from the intended neighbor, as confirmed by received and advertised route views.

Correct the route-reflector client topology and validate reflected path distribution without introducing loops. Its normal acceptance signal would be authorized clients receive the expected reflected iBGP paths and preserve appropriate originator or cluster-loop protection. Here the deciding check is different: only approved prefixes are advertised to or accepted from the intended neighbor, as confirmed by received and advertised route views.

Set compatible IS-IS circuit levels on both ends of the interface and verify hello and neighbor state. That could help in a case involving IS-IS adjacency circuit level. This failure instead depends on BGP import export control; BGP import policy governs received routes and export policy governs outbound advertisements; changing the wrong direction cannot enforce the intended boundary.

The proposal changes IBGP route reflection; that is not the failure isolated by the facts. It could leave BGP import export control unresolved even if its own test passed. BGP import policy governs received routes and export policy governs outbound advertisements; changing the wrong direction cannot enforce the intended boundary.

Assign each OSPF router a unique stable router ID and confirm the resulting neighbor and link-state database identities. That could help in a case involving stable OSPF router identifier. This failure instead depends on BGP import export control; BGP import policy governs received routes and export policy governs outbound advertisements; changing the wrong direction cannot enforce the intended boundary.

Correct the locally expected peer AS and actual neighbor AS identity and validate the BGP OPEN exchange. That could help in a case involving BGP ASN and OPEN negotiation. This failure instead depends on BGP import export control; BGP import policy governs received routes and export policy governs outbound advertisements; changing the wrong direction cannot enforce the intended boundary.

The control protects multiprotocol BGP IPv6 AFI. It does not establish the ongoing IPv6 over IPv4 tunnel underlay behavior required in this network. An IPv6-over-IPv4 tunnel depends on the IPv4 underlay that transports encapsulated packets; overlay route presence cannot replace underlay connectivity.

This is a useful guard against OSPF interface metric selection, but it is not scoped to the observed IPv6 over IPv4 tunnel underlay failure. An appropriate test would show that both IPv4 endpoint paths are reachable and IPv6 packets traverse the encapsulated link end to end.

The control protects IS-IS IPv6 topology TLVs. It does not establish the ongoing IPv6 over IPv4 tunnel underlay behavior required in this network. An IPv6-over-IPv4 tunnel depends on the IPv4 underlay that transports encapsulated packets; overlay route presence cannot replace underlay connectivity.

Correct the route-reflector client topology and validate reflected path distribution without introducing loops. That could help in a case involving IBGP route reflection. This failure instead depends on EBGP multihop reachability; EBGP sessions to nonadjacent neighbors need suitable multihop TTL and transport reachability; routing reachability alone can be insufficient.

The proposal changes IPv6 static next-hop scope; that is not the failure isolated by the facts. It could leave EBGP multihop reachability unresolved even if its own test passed. EBGP sessions to nonadjacent neighbors need suitable multihop TTL and transport reachability; routing reachability alone can be insufficient.

Apply an approved outbound AS-path prepend policy on the less-preferred advertised path and validate what peers receive. Its normal acceptance signal would be external route advertisements show the intended relative AS-path lengths and measured inbound behavior is compared with the goal. Here the deciding check is different: the intended multi-hop peer establishes while IP reachability and any required loopback-source configuration are correct.

This is a useful guard against BGP communities and routing policy, but it is not scoped to the observed BGP ASN and OPEN negotiation failure. An appropriate test would show that the peer moves to Established with the agreed local and remote AS values and appropriate session messages. Applied here, the relevant facts are: A replacement edge router sends an OPEN claiming the wrong AS and the upstream session never reaches Established. The question asks which ongoing control would most directly detect or prevent the same failure from recurring.

Continuously diff effective import/export policies against approved prefix filters and peer relationships. The monitored boundary differs from BGP ASN and OPEN negotiation, so the original weakness might reappear unnoticed. BGP peers validate AS identity during OPEN negotiation; transport reachability by itself does not establish a valid BGP session.

This is a useful guard against filter-based forwarding table selection, but it is not scoped to the observed BGP ASN and OPEN negotiation failure. An appropriate test would show that the peer moves to Established with the agreed local and remote AS values and appropriate session messages.

Test BFD session negotiation and routing reaction times during controlled failures. The monitored boundary differs from NSR protocol state replication, so the original weakness might reappear unnoticed. NSR uses GRES infrastructure while preserving routing protocol state on the backup Routing Engine, avoiding reliance on neighbor restart helpers.

Exercise VRRP failover and confirm virtual gateway reachability under device and link failure. The monitored boundary differs from NSR protocol state replication, so the original weakness might reappear unnoticed. NSR uses GRES infrastructure while preserving routing protocol state on the backup Routing Engine, avoiding reliance on neighbor restart helpers.

Capture DIS election and pseudonode observations during shared LAN commissioning and role changes. The monitored boundary differs from NSR protocol state replication, so the original weakness might reappear unnoticed. NSR uses GRES infrastructure while preserving routing protocol state on the backup Routing Engine, avoiding reliance on neighbor restart helpers.

Every router has a distinct planned router ID and the LSDB tracks the appropriate originating router consistently. It would validate a separate stable OSPF router identifier operation, not the change needed here. Confirm instead that the same virtual gateway remains reachable when the active VRRP router is failed in a controlled test.

During a controlled routing restart, participating neighbors retain forwarding state only for the permitted grace interval and then converge correctly. It would validate a separate graceful restart peer assistance operation, not the change needed here. Confirm instead that the same virtual gateway remains reachable when the active VRRP router is failed in a controlled test.

A controlled link or peer failure causes BFD Down and timely routing reconvergence rather than waiting for long protocol timers. It would validate a separate BFD fast failure detection operation, not the change needed here. Confirm instead that the same virtual gateway remains reachable when the active VRRP router is failed in a controlled test.

The proposal changes IS-IS NET and system ID; that is not the failure isolated by the facts. It could leave IS-IS LAN designated intermediate system unresolved even if its own test passed. On an IS-IS broadcast LAN the DIS originates pseudonode LSPs and may be re-elected when priority changes; the process differs from OSPF DR behavior.

The proposal changes OSPFv3 IPv6 neighbor reachability; that is not the failure isolated by the facts. It could leave IS-IS LAN designated intermediate system unresolved even if its own test passed. On an IS-IS broadcast LAN the DIS originates pseudonode LSPs and may be re-elected when priority changes; the process differs from OSPF DR behavior.

The proposal changes IS-IS L1 and L2 reachability; that is not the failure isolated by the facts. It could leave IS-IS LAN designated intermediate system unresolved even if its own test passed. On an IS-IS broadcast LAN the DIS originates pseudonode LSPs and may be re-elected when priority changes; the process differs from OSPF DR behavior.

Exercise VRRP failover and confirm virtual gateway reachability under device and link failure. That ongoing check is for VRRP virtual gateway failover; it would not reliably detect recurrence of BGP local preference. LOCAL_PREF is an intradomain BGP path attribute that normally influences preferred outbound exit for routes inside the AS.

Test MED behavior in realistic same-neighbor-AS scenarios and monitor actual received path attributes. The monitored boundary differs from BGP local preference, so the original weakness might reappear unnoticed. LOCAL_PREF is an intradomain BGP path attribute that normally influences preferred outbound exit for routes inside the AS.

The control protects EBGP multihop reachability. It does not establish the ongoing BGP local preference behavior required in this network. LOCAL_PREF is an intradomain BGP path attribute that normally influences preferred outbound exit for routes inside the AS.