JN0-352 Exam Dumps - Enterprise Routing and Switching, Specialist (JNCIS-ENT)

Nonstop active routing is specifically engineered to be completely transparent to the rest of the network: rather than relying on neighboring routers to preserve state during a Routing Engine switchover the way graceful restart does, NSR keeps a fully synchronized instance of the routing protocol process (rpd) running continuously on the backup Routing Engine, mirroring protocol adjacencies, the RIB, and session state in real time. Because neighbors never observe a session reset or restart signal during an NSR-driven switchover, there is no dependency on those neighbors supporting or enabling graceful restart extensions at all — this is the core architectural advantage that distinguishes NSR from GR and is precisely why the first and third answer choices are incorrect distractors. What NSR does require locally is Graceful Routing Engine Switchover (GRES) enabled first, since NSR is built as an extension on top of GRES and depends on it to synchronize kernel and interface state between the two Routing Engines before protocol-level synchronization can occur. Additionally, Juniper's official guidance mandates that both Routing Engines run the identical Junos OS software version; mismatched versions between the primary and backup Routing Engine can introduce incompatible internal data structures or feature behavior during state replication, jeopardizing the integrity of a switchover and is explicitly called out as a hard operational requirement rather than a mere best practice. Reference topics: Junos Enterprise Routing – High Availability, Nonstop Active Routing Requirements and GRES Dependency.

The diagnostic output explicitly states the root cause: the local router has only the inet6-unicast address family configured for this peer, while the remote router advertised inet-unicast and inet-vpn-unicast in its OPEN message, and BGP requires at least one common negotiated address family (NLRI type) between two peers for a session to remain established; with zero overlap between the two sides' configured families, the session is torn down immediately after the OPEN exchange, which is precisely why the peer state shows Active rather than Established. This confirms the mismatched-address-family statement directly and unambiguously from the exhibit's own Down reason and Detail reason fields. The diagnostic tool's own embedded Suggestion text goes further, explicitly advising the administrator to additionally verify that the local-address configured for the peer matches the remote router's configured neighbor address and vice versa — a secondary, commonly encountered condition in which mismatched or effectively duplicated/incorrect address bindings between the two sides' neighbor statements can independently prevent a session from completing correctly, even once the family mismatch is resolved. This is why address-configuration consistency between the peers is flagged as a second concern worth checking in this scenario. Nothing in the exhibit references NTP or time synchronization at all, nor does anything in the output reference authentication, an MD5 mismatch, or any related failure signature; both of those conditions would present through entirely different diagnostic messages than the one shown here. Reference topics: Junos Enterprise Routing – BGP, Address Family Negotiation and the show bgp diagnostics neighbor Command.

Root protection (root guard) must always be applied on the ports of the switches you trust to remain root-bridge-eligible, specifically on the interfaces facing away from the legitimate root and toward parts of the network where an untrusted or rogue device could plausibly appear and begin transmitting superior BPDUs. In this topology, Switch-1 is the intended, permanent root bridge (lowest priority, 4k), and Switch-2 is its aggregation-layer peer; both sit above the access layer, where Switch-3 and Switch-4 connect downstream toward end-user-facing infrastructure and where an accidental or malicious rogue switch is realistically most likely to be introduced. The ge-0/0/6 and ge-0/0/8 interfaces on Switch-1 and Switch-2 are precisely the downlink ports facing that access layer, meaning they are the exact points at which a rogue switch's superior BPDU (one advertising a lower priority than the legitimate root) would first be received if such a device appeared beneath Switch-3 or Switch-4. Applying root protection on those specific interfaces causes Junos to immediately block (move to a root-inconsistent, discarding state) any port that receives a superior BPDU, preventing the rogue device from ever being accepted as root, while normal, non-superior BPDUs continue to be processed without disruption. Applying root guard on Switch-1 and Switch-2's peer link (ge-0/0/12/13) would be inappropriate, since that link legitimately connects two trusted, root-eligible switches. Reference topics: Junos Enterprise Switching – Spanning Tree Protocols, Root Protection Placement Strategy.