Juniper JN0-281 Dumps Questions Answers

EBGP is defined as BGP peering between different autonomous systems, which makes statement A correct. In data center IP fabrics, it is common to assign different private AS numbers to leaves and spines or to use a structured AS design so that every leaf forms EBGP sessions to each spine. This provides clear policy boundaries, straightforward troubleshooting, and predictable route propagation without needing an additional interior gateway protocol to carry underlay reachability.

Statement C is also correct because EBGP can be deployed without a supporting IGP. BGP itself can distribute the underlay routes needed for fabric reachability, such as loopback addresses and point to point link prefixes. This is a widely used approach for leaf spine fabrics because it reduces protocol complexity and avoids running multiple control planes for the underlay. Convergence can be improved using multipath, rapid failure detection mechanisms, and consistent routing policy.

Statement B is incorrect because BGP within a single AS is IBGP, not EBGP. Statement D is incorrect because while some designs may choose to run an IGP and use BGP only for certain functions, EBGP does not inherently require an IGP to operate or to provide underlay connectivity in a fabric design.

Nonstop active routing is the Junos high availability capability that focuses on preserving routing protocol operation and routing information across a Routing Engine switchover. In platforms with redundant Routing Engines, a failure of the primary Routing Engine can otherwise reset routing protocol processes, tear down adjacencies, and trigger reconvergence. NSR mitigates this by synchronizing routing protocol state so that the backup Routing Engine can continue routing protocol operations with minimal disruption. This includes maintaining protocol session continuity and keeping the routing information base stable, which directly protects traffic that depends on those routes.

In data center environments, this is particularly important for routed fabrics where BGP or OSPF underlay reachability supports overlay services and east west application traffic. By keeping routing information consistent during the control-plane transition, NSR reduces route churn and helps avoid transient blackholing or microbursts caused by reconvergence.

GRES is closely related but addresses a different scope. GRES helps the forwarding plane continue forwarding during a Routing Engine switchover by preserving certain system and interface states. However, GRES alone does not guarantee that routing protocol sessions and routing information remain uninterrupted. BFD and LACP are valuable availability tools, but they are not Routing Engine redundancy features and do not preserve routing state during a Routing Engine failover.

In Junos OSPF, the passive setting is used when you want the prefix on an interface to be advertised into OSPF, but you do not want the interface to form OSPF neighbor adjacencies or send OSPF Hello packets. This is a common data center requirement for server-facing, management, or loopback-related interfaces where you want the subnet to be reachable through the routing domain, but there is no OSPF-capable neighbor on that link. By making the interface passive, the router still includes the connected network in OSPF as an internal route, so other routers learn how to reach that subnet. At the same time, the interface does not participate in adjacency formation, which reduces unnecessary protocol chatter and eliminates the risk of accidentally forming neighbors on an untrusted or unintended segment.

The other options do not meet the requirement. Interface-type changes the OSPF network type behavior, such as broadcast or point-to-point, but it does not stop adjacency formation while still advertising the network. Strict-bfd relates to failure detection behavior when BFD is used with routing protocols and does not control whether OSPF forms neighbors. Link-protection is related to fast reroute and protection mechanisms, not suppressing OSPF adjacency on an interface.