Free JN0-650 Practice Test Questions | Know You're Ready for Enterprise Routing and Switching - Professional (JNCIP-ENT)

Explanation:

C. Pure Type-5 routes are also known as IP-VRF-to-IP-VRF.
This is the foundational concept behind pure Type-5 routes. Because these routes carry all necessary forwarding information and do not rely on an overlay next-hop or a supporting Type-2 route, they enable direct Layer 3 communication between VRFs (Virtual Routing and Forwarding instances) across different data centers. This model is formally defined in IETF RFC 9136 and is referred to as the "IP-VRF-to-IP-VRF" or "interface-less IP-VRF-to-IP-VRF" model .

D. Pure Type-5 routes are advertised with the MAC extended community.
The key distinction of a pure Type-5 route is that it includes a Router's MAC Extended Community. This BGP extended community carries the MAC address of the advertising switch (VTEP - VXLAN Tunnel Endpoint). It serves a critical role: it provides the necessary next-hop reachability information for the IP prefix, removing the need for a separate overlay next-hop or a recursive route lookup .

Why A and B are incorrect:

A. Pure Type-5 routes rely on Type-7 sync routes.
This statement is false. Type-7 routes are not a standard EVPN route type used in this context. The standard EVPN route types include Type-2 (MAC/IP Advertisement), Type-3 (Inclusive Multicast), Type-4 (Ethernet Segment), and Type-5 (IP Prefix). Pure Type-5 routes are specifically designed to avoid relying on other route types, not to depend on a non-existent Type-7 .

B. Pure Type-5 routes require an overlay next hop.
This statement is the opposite of the truth. The entire purpose of a "pure" Type-5 route is to NOT require an overlay next-hop. In the standard (or non-pure) Type-5 route model, a gateway IP address is required as an overlay next-hop, which in turn depends on a Type-2 route for recursive resolution. A pure Type-5 route removes this dependency by embedding the next-hop information directly within the route via the Router's MAC Extended Community .

Reference

Juniper Networks Documentation: Confirms pure Type-5 routes are for IP-VRF-to-IP-VRF and are advertised with a router MAC extended community, requiring no overlay next-hop or Type-2 route .

IETF RFC 9136: Defines the "interface-less IP-VRF-to-IP-VRF model" that underlies pure Type-5 route operation

Explanation:

The inet.2 table is Junos’ dedicated utility routing table for recursive next-hop resolution. When a route (e.g., an EVPN Type‑5 prefix) has a next‑hop address that requires further lookup—such as an overlay gateway IP that must be resolved to a directly connected interface or tunnel endpoint—Junos performs that recursive lookup in inet.2. Querying inet.2 (via show route table inet.2) allows you to validate whether the recursive chain is complete and reachable.

Why the other options are incorrect:

B. default-switch.evpn.0 – Stores EVPN MAC/IP routes (Type‑2, Type‑3, Type‑5) for the default switching instance, used for forwarding decisions, not recursive next‑hop resolution.

C. inet.3 – Holds MPLS label-switched path (LSP) next hops; used for MPLS tunnel resolution (e.g., RSVP, LDP), not for generic recursive lookups in EVPN.

D. vxlan.inet – Not a valid Juniper routing table. VXLAN next‑hop information resides in tables like evpn.0, mpls.0, or is resolved via inet.2.

References:

Juniper TechLibrary: “Routing Tables – inet.2 table is used for recursive next‑hop resolution”

“Junos Routing Fundamentals” – recursive lookups use utility tables like inet.2

Explanation:

In OSPFv2, Type‑1 (router LSA) and Type‑2 (network LSA) are area‑scoped—they never leave the area in which they originate. When an ABR (like R2) connects Area 0 to Area 2, it does not forward Type‑1 or Type‑2 LSAs from Area 1 into Area 0 or Area 2. Instead, the ABR (R1) in Area 1 summarizes those intra‑area routes into Type‑3 (summary LSA) and floods them into the backbone Area 0. R2 receives those Type‑3 LSAs from Area 0 and installs them as inter‑area routes. This explains why R2 has an inter‑area route to R3’s network but has no Type‑1/Type‑2 LSAs from Area 1 in its database.

Why other options are incorrect:

A. R2 filtering via import policy
– Possible in principle, but the question describes standard OSPF behavior, not a configured filter. No evidence of policy exists.

B. Junos disables Type‑1/Type‑2 LSAs by default
– False. Junos follows standard OSPF; Type‑1/Type‑2 never cross areas by protocol design, not by a disable feature.

C. R2 running OSPFv3
– The question states OSPFv2 deployment. OSPFv3 also does not flood Type‑1/Type‑2 across areas, so this would not explain the symptom.

References:

RFC 2328 (OSPFv2) – Section 3.3: Type‑1 and Type‑2 LSAs are flooded only within their originating area.

Juniper TechLibrary: OSPF Area Types – “ABRs convert intra‑area routes to Type‑3 LSAs for other areas.”

Explanation:

A. This custom DSCP classifier must be associated with logical interfaces.
– Correct. In Junos CoS, after defining a classifier (like my-classifier), you must explicitly associate it with a logical interface using the classifiers statement under [edit class-of-service interfaces unit ]. Classifiers are not automatically applied to all interfaces; they are interface‑specific.

C. The configuration imports all default classification assignments that are not specified.– Correct. The import default; statement in the classifier configuration explicitly imports the system’s default DSCP classification mapping. Any DSCP value not matched by the user‑defined entries will fall back to the default classification (e.g., best‑effort forwarding class). This ensures complete coverage without needing to redefine every possible code point.

Why B and D are incorrect:

B. This custom DSCP classifier must be associated with physical interfaces.
– Incorrect. Junos attaches classifiers to logical interfaces (unit level), not to physical (ge-, xe-) interfaces directly. Physical interfaces may have multiple logical units, each potentially using a different classifier.

D. The default classification assignment overwrites all specified classifications.
– Incorrect. import default does not overwrite user‑specified entries. Instead, it acts as a fallback: user‑defined code points (like ef, cs3, af31, af41) take priority. If a DSCP value matches a user entry, that mapping is used; otherwise, the default classification applies.

References:

Juniper TechLibrary: “Classifiers – Importing the Default Classifier” – import default adds default mappings as a low‑priority fallback.

Juniper TechLibrary: “Applying Classifiers to Logical Interfaces” – Classifiers are configured under interfaces unit .

Explanation:

In Junos OS for EX Series switches, the supplicant mode on an 802.1X authenticator interface determines how many devices can connect. To restrict port access to only one device at a time, you must configure single-secure mode.

Per Juniper documentation :

single-secure – Authenticates only one end device to connect to the port. No other device is allowed to connect until the first device logs out. This directly achieves your goal of limiting port access to a single device.

Why other options are incorrect:

A. Enable MAC RADIUS restrict
– This forces the interface to use only MAC RADIUS authentication (bypassing 802.1X) but does not limit the number of connected devices. It controls how authentication happens, not how many devices can access the port .

B. Change the supplicant mode to multiple
– This allows multiple devices to connect to the port, with each device authenticated individually. This is the opposite of limiting to one device .

D. Change the maximum EAPOL request to 1
– This controls how many EAPOL (Extensible Authentication Protocol over LAN) request retransmissions are sent before timing out, not the number of devices allowed on the port.

References:

Juniper TechLibrary – "802.1X Authentication: single-secure supplicant allows only one end device to connect to the port"

Juniper Configuration Guide– supplicant (multiple | single | single-secure)

Explanation:

In Juniper EX Series switches, a scheduler defines the properties of an output queue. According to Juniper's official documentation, a scheduler configures four key properties of a queue: the amount of interface bandwidth assigned to the queue, the size of the memory buffer allocated for storing packets, the priority of the queue, and the drop profiles associated with the queue.

A. It defines a buffer size of the queue to which it is assigned
– Correct. The buffer-size configuration statement controls the delay buffer bandwidth, which provides packet buffer space to absorb burst traffic. This buffer size can be configured as a percentage of the total buffer, a specific value, or the remaining available buffer.

D. It identifies the priority of the queue to which it is assigned
– Correct. Priority scheduling determines the order in which an output interface transmits traffic from queues, ensuring important traffic receives better access to the outgoing interface. Junos supports multiple priority levels including low (packets transmitted last) and strict-high (packets transmitted first).

Why B and C are incorrect:

B. It defines interface rate-limiting
– Incorrect. Rate-limiting (shaping) is configured separately using the shaping-rate statement, not as a core property of the scheduler itself. While schedulers manage transmission rates, rate-limiting/shaping is a distinct CoS component.

C. It provides DiffServ code translation
– Incorrect. DiffServ code point translation is handled by classifiers (which map code points to forwarding classes) and rewrite rules (which mark outgoing packets), not by schedulers. Schedulers operate on queues after classification and rewriting have occurred.

References:

Juniper TechLibrary – "Understanding CoS Schedulers" – Scheduler properties include buffer size and queue priority

Juniper J-Web Documentation – Scheduler configuration includes buffer size and scheduling priority fields

Explanation:

The question asks which EVPN route types advertise an Ethernet Segment Identifier (ESI) without advertising a MAC address. According to RFC 7432, EVPN defines several route types, each with a specific purpose and set of advertised information.

A. Type 1 (Ethernet Auto-Discovery Route) – Correct.
Type 1 routes are used for network-wide messaging in multi-homing scenarios and carry the ESI in their NLRI. They do not advertise a MAC address—their purpose is to signal Ethernet segment reachability and enable fast convergence . These routes are advertised on a per-ESI and per-EVI basis .

D. Type 4 (Ethernet Segment Route) – Correct.
Type 4 routes are used for automatic discovery of PE devices attached to the same Ethernet segment and for Designated Forwarder (DF) election . The route carries the ESI but contains no MAC address or label information—its purpose is multi-homing coordination, not MAC advertisement .

Why B and C are incorrect:

B. Type 2 (MAC/IP Advertisement Route) – Incorrect.
Type 2 routes are used to advertise MAC addresses (and optionally IP addresses) learned by a PE router . These routes do include a MAC address field (48 bits) and are the primary mechanism for distributing MAC reachability information across the EVPN domain .

C. Type 3 (Inclusive Multicast Ethernet Tag Route – IMET) – Incorrect.
Type 3 routes are used for broadcast, unknown unicast, and multicast (BUM) traffic optimization . These routes do not carry an ESI; they carry route distinguisher, Ethernet tag ID, and IP address information to enable multicast tunnel establishment.

References:

RFC 7432, Sections 5–8 (EVPN route type definitions)
Juniper TechLibrary – EVPN Route Types
IP Infusion – "EVPN Route Types" (Type 1 and Type 4 definitions)

Explanation:

C. Stub areas do not support virtual links.
– Correct. Virtual links allow a non-backbone area to connect to the backbone area through another non-backbone area when a direct physical connection is not available. However, a virtual link cannot traverse a stub area because stub areas do not carry complete routing information and lack the necessary Type-3 summary LSAs to support virtual link establishment .

D. Stub areas can be converted into totally stubby areas.
– Correct. A regular stub area blocks Type-5 external LSAs but still allows Type-3 summary LSAs from other areas. Converting to a totally stubby area further restricts the area by blocking all Type-3 summary LSAs as well, leaving only intra-area routes and a default route. The ABR simply needs the no-summaries parameter configured—no area type change is required .

Why A and B are incorrect

A. Stub areas can have an ASBR
– Incorrect. A stub area, by definition, cannot contain an ASBR (Autonomous System Boundary Router). External routes (Type-5 LSAs) are blocked from entering stub areas, so having an ASBR within a stub area would generate Type-5 LSAs, violating stub area rules. For external route injection into a stub-like area, you must use an NSSA (Not-So-Stubby Area), which uses Type-7 LSAs .

B. Stub areas can also be not-so-stubby areas
– Incorrect. An area cannot be both a stub area and an NSSA simultaneously—these are mutually exclusive configurations. The two area types serve different purposes: stub areas block all external routes, while NSSAs allow controlled external route injection via Type-7 LSAs .

References
Juniper TechLibrary – OSPF Stub Areas, Totally Stubby Areas, and NSSA configuration guides
RFC 2328 (OSPFv2) – Stub area definitions and restrictions
HPE OSPFv3 documentation – Stub area virtual link limitations