매달, 우리는 1000명 이상의 사람들이 시험 준비를 잘하고 시험을 잘 통과할 수 있도록 도와줍니다.
Service Provider Routing and Switching - Specialist (JNCIS-SP) 온라인 연습
최종 업데이트 시간: 2026년03월30일
당신은 온라인 연습 문제를 통해 Juniper JN0-364 시험지식에 대해 자신이 어떻게 알고 있는지 파악한 후 시험 참가 신청 여부를 결정할 수 있다.
시험을 100% 합격하고 시험 준비 시간을 35% 절약하기를 바라며 JN0-364 덤프 (최신 실제 시험 문제)를 사용 선택하여 현재 최신 65개의 시험 문제와 답을 포함하십시오.
정답:
Explanation:
In the Border Gateway Protocol (BGP), the Split Horizon rule is a fundamental loop-prevention mechanism for internal sessions. This rule dictates that a BGP speaker must not advertise a route learned from an Internal BGP (IBGP) peer to any other IBGP peer within the same Autonomous System (AS). This ensures that routes do not circulate infinitely inside a network, as IBGP does not modify the AS_PATH attribute. Consequently, to maintain full reachability, a network normally requires a "full mesh" of IBGP sessions, where every BGP-speaking router is directly peered with every other router.
In the provided exhibit, ROUTER_1is part of AS 64523. The requirement is for ROUTER_1 to take prefixes learned from its internal peers and re-advertise them to other internal peers in the same AS. This behavior is a direct violation of the standard Split Horizon rule. According to Juniper Networks technical documentation, the standard solution to scale IBGP without a full mesh is to configure Route Reflection.
When a router is configured as a Route Reflector (RR), it is permitted to "reflect" (re-advertise) routes learned from one IBGP peer to another. In Junos OS, the mechanism to enable Route Reflection is to configure a cluster ID within the BGP group. By adding the cluster keyword followed by a unique 32-bit identifier (usually the router's loopback address) to the internal BGP group configuration, the router assumes the role of an RR. It then follows specific reflection rules:
Routes learned from an EBGP peer are reflected to all IBGP peers.
Routes learned from a Route Reflector Client are reflected to all other clients and non-clients.
Routes learned from anon-client are reflected to all clients.
Option A is incorrect because BGP advertisement rules are hard-coded; a standard export policy cannot override the Split Horizon rule.
Option C handles traffic engineering tags but does not enable route reflection.
Option D would change the session to EBGP, which does not address the internal reachability requirement within AS 64523. Therefore, configuring the cluster ID is the only valid way to achieve the desired re-advertisement behavior.
정답:
Explanation:
In Junos OS, astatic route is a manually configured entry in the routing table. Unlike dynamic routes, which have built-in timers and aging mechanisms, static routes are generally "permanent" as long as their conditions for validity are met.
정답:
Explanation:
In the IS-IS (Intermediate System to Intermediate System) protocol as implemented in Junos OS, routers can operate at two hierarchical levels: Level 1 (L1) for intra-area routing and Level 2 (L2) for inter-area backbone routing. By default, a Juniper router and its interfaces are configured to act as Level 1/2, meaning they will attempt to form adjacencies at both levels simultaneously.
According to Juniper Networks technical documentation, the show isis interface command provides a granular view of how the protocol is interacting with specific local links. In the provided exhibit, we must examine the L (Level) column and the DR (Designated Router) status columns to understand R1's operational state.
Level Configuration: Under the L column for both the physical interface ge-0/0/0.0 and the loopback lo0.0, the value is strictly2. This indicates that these interfaces have been explicitly configured to operate only at Level 2.
Adjacency Capabilities: For the interface ge-0/0/0.0, the Level 1 DR field is marked as Disabled. This confirms that R1 is not participating in Level 1 operations on this link; it will not transmit Level 1 Hello PDUs, nor will it listen for them. Consequently, R1 is incapable of forming a Level 1 adjacency with R2 on this segment.
Metric Implications: The exhibit shows an L1/L2 Metric of100/100. In Junos, "narrow" metrics (the default) are limited to a maximum value of 63 per interface. A metric of 100 indicates that wide metrics (wide-metrics-only) have been enabled. Therefore, option A is incorrect because the router is using wide metrics.
Since the prompt states the adjacency is "up, " and the interface is restricted to Level 2, we can conclude that R1 only forms a Level 2 adjacency with R2 (Option B). Even though an L1 metric of 100 is displayed in the table as a configured value, it is not actually "advertised" in a Link-State PDU because the Level 1 protocol is disabled on that interface.
정답:
Explanation:
In the Juniper Networks Junos operating system, the management of routing information is partitioned into several distinct routing tables (RIBs), each serving a specific architectural purpose. When dealing with Multiprotocol Label Switching (MPLS), understanding the distinction between inet.0 and inet.3 is fundamental for troubleshooting and traffic engineering.
Theinet.3routing table is specifically designed to store the egress IPv4 addresses of Label-Switched Paths (LSPs). When an ingress router successfully establishes an LSP (via RSVP or LDP), it places the host address of the egress router (the tail-end) into the inet.3 table. This table is not used for general packet forwarding; instead, it is primarily used by the Border Gateway Protocol (BGP) for next-hop resolution. When BGP receives a route, it checks both inet.0 and inet.3 to resolve the next hop. If a matching entry exists in inet.3, the router knows it can reach that destination via an MPLS tunnel, allowing for the encapsulation of BGP traffic within MPLS.
In contrast, inet.0is the default unicast routing table used for standard IPv4 forwarding and contains routes learned via IGPs (OSPF, IS-IS) or static routing.inet.1is utilized for multicast forwarding (MBGP), andinet.2 is typically used for Multicast Source Discovery Protocol (MSDP) or RPF checks in multicast environments. By isolating LSP egress points in inet.3, Junos prevents MPLS-specific paths from interfering with standard IGP path selection unless the administrator explicitly chooses to merge them (e.g., using the traffic-engineering bgp-igp command). Therefore, by default, the ingress router maintains its list of reachable LSP endpoints in inet.3.
정답:
Explanation:
In the IPv6 architecture, the base header is kept at a fixed size of 40 bytes to streamline processing. Any additional features or options are handled by Extension Headers, which are inserted between the IPv6 header and the upper-layer protocol. According to Juniper Networks technical documentation and RFC 8200, when a source node needs to list one or more intermediate nodes to be "visited" on the way to the final destination, it utilizes the Routing extension header (Option B).
The Routing header is functionally similar to the "Source Route" option in IPv4. When a packet contains a Routing header, it is addressed to the first intermediate node listed in the header. That node examines the header, swaps its own address with the next address in the list, and forwards the packet. This process continues until the packet reaches the final destination. This is a foundational component for technologies like Segment Routing over IPv6 (SRv6), where the Routing header (specifically the Segment Routing Header or SRH) is used to steer traffic through a specific set of service instructions or nodes.
To distinguish this from the other options:
Hop-by-hop options (Option A): These carry information that must be examined by every node along the path (such as Router Alert), not just specific intermediate nodes.
Fragment (Option C): This is used only when the source node needs to fragment a packet that exceeds the path MTU.
Destination options (Option D): These carry optional information intended specifically for the destination node (or nodes listed in a Routing header), but they do not dictate the path themselves.
정답:
Explanation:
When transitioning to an IPv6 environment usingOSPFv3 (the version of OSPF designed for IPv6), there are significant architectural differences compared to OSPFv2 (IPv4). According to Juniper Networks technical documentation, OSPFv3 was redesigned to be more protocol-agnostic.
Router ID (Option C):
Despite OSPFv3 routing IPv6 (which uses 128-bit addresses), the OSPF Router ID remains a32-bit value formatted like an IPv4 address (e.g., 1.1.1.1). This is a common point of confusion. In a pure IPv6 environment where no IPv4 addresses are configured on any interfaces, a Juniper router cannot automatically
derive a Router ID. Therefore, the administrator must manually configure a 32-bit Router ID under [edit routing-options] for the OSPFv3 process to initialize.
Interface Configuration (Option D):
OSPFv3 runs directly over the IPv6 link-local scope. Unlike OSPFv2, it does not require an IPv4 address to function. Therefore, interfaces are only required to be configured with family inet6 (Option D). You do not need "dual-stack" (both IPv4 and IPv6) functionality just to run OSPFv3. The protocol uses the link-local address (fe80: : /10) of the interface for neighbor adjacencies and as the next hop for routing updates. This separation allows OSPFv3 to carry multiple "address families" (both IPv4 and IPv6 unicast) if needed, but the base requirement for an IPv6-only network is simply the family inet6 configuration.
정답:
Explanation:
IS-IS is a link-state protocol that relies on the rapid and consistent flooding of Link-State PDUs (LSPs) to ensure that every router in an area has an identical view of the topology. To manage the "freshness" of information, IS-IS uses a Sequence Number―a 32-bit unsigned integer that increments every time the originating router makes a change to its LSP.
According to Juniper Networks technical documentation, when a router receives an LSP, it performs a comparison between the received LSP and the version it currently holds in its Link-State Database (LSDB). If the received LSP has a higher sequence number, the router concludes that this is "newer" and more accurate information. The router will then perform two immediate actions:
Update: It replaces the older LSP in its LSDB with the newly received version.
Flood: It propagates the new LSP to all other neighbors (except the one that sent it) to ensure the entire area converges on the new data.
If the sequence numbers were equal, the router would ignore the incoming PDU as it already has the information. If the received sequence number were lower, the router would conclude its own database is more recent and would actually send its own "newer" version back to the neighbor to bring them up to date (a process called "poisoning" or refreshing the neighbor). Complete Sequence Number PDUs (CSNPs) (Option C) are used during initial database synchronization or periodic checks on broadcast links, but the primary response to a "newer" LSP is immediate database update and flooding.
정답:
Explanation:
In a Juniper Networks environment, establishing a functional Multiprotocol Label Switching (MPLS) Label-Switched Path (LSP) requires synchronized control plane operations. According to Juniper technical documentation, the most common reason for an LSP to remain in the "Down" state at the ingress router is a failure of the Constrained Shortest Path First (CSPF) algorithm during the path computation phase.
The provided exhibit for routerR1reveals a critical error in the show mpls lsp detail output: "CSPF: could not determine self". This specific error indicates that the CSPF process is unable to find its own local router ID within the Traffic Engineering Database (TED). For CSPF to build a valid TED, the underlying Interior Gateway Protocol (IGP), such as OSPF, must be configured to flood opaque link-state advertisements (Type 10 LSAs) that carry traffic engineering attributes. As seen in the OSPF configuration, traffic engineering is not enabled. Therefore, issuing the set protocols ospf traffic-engineering command (Option D) will allow R1 to populate the TED with its own local information and that of its neighbors, enabling CSPF to calculate a valid path.
Alternatively, an administrator can choose to bypass the requirement for a TED entirely by disabling CSPF on the specific LSP. By issuing the set protocols mpls label-switched-path to-r3 no-cspf command (Option B), the router will stop attempting to perform a constrained path calculation. Instead, the signaling protocol (RSVP) will rely on the standardinet.0routing table to determine the hop-by-hop path to the egress destination (192.168.100.3), allowing the LSP to establish without traffic engineering constraints.
Regarding the other options, while family mpls is required on all transit interfaces, the ingress loopback interface (lo0) generally does not require it for standard LSP signaling unless it's used as a transit hop. Furthermore, adding a static route toinet.3 (Option A) is used for next-hop resolution of BGP routes over LSPs but does not assist in the signaling or establishment of the LSP itself.
정답:
Explanation:
In Juniper Networks Junos OS, a "hidden" route in the BGP table typically signifies that the router has received the prefix but cannot install it into the active routing table because the BGP next hop is unreachable. This is a common occurrence in service provider environments when transitioning between External BGP (EBGP) and Internal BGP (IBGP).
According to Juniper technical documentation, when an EBGP speaker (R1) advertises a prefix to its peer (R2), it sets the next hop to its own interface IP address ($172.16.10.1$). By default, when R2 re-advertise that prefix to its IBGP peer (R3), it preserves the original EBGP next-hop address. Unless R3 has a specific route in its Interior Gateway Protocol (IGP) or a static route to reach the $172.16.10.1$ subnet, it will mark the route as unusable (hidden).
In the exhibit, the show route output onR3explicitly shows the nexthop for $203.0.113.0/24$ as $172.16.10.1$. Since this route is marked "hidden, " we can conclude R3 does not know how to reach R2's external peering link. To resolve this, the network administrator must modify the next-hop attribute before the route is sent to R3.
By adding the statement set policy-options policy-statement export-to-ibgp then next-hop self (Option B)
on routerR2, R2 will replace the external next-hop ($172.16.10.1$) with its own internal peering address
($172.16.20.1$) before advertising the route to R3. Because R3 already has a direct or IGP connection to R2's internal address, it will successfully resolve the next hop, and the route will transition from "hidden" to "active."
Option A is unnecessary because the route is already being exported; Option C is redundant as the policy is already applied to the IBGP group; and Option D changes path preference but does not solve the underlying reachability problem.
정답:
Explanation:
In the provided exhibit, the output of the command show spanning-tree interface for switch1 reveals critical details about the Spanning Tree Protocol (STP) operational state.
The first correct statement is that the switch1 device is the root bridge (Option B). This is determined by comparing the "Port ID" column with the "Designated port ID" column, as well as checking the "Designated bridge ID". In the exhibit, for every interface listed (from ge-0/0/6.0 to ge-0/0/13.0), the Port ID and the Designated port ID are identical. Furthermore, every port is in the "FWD" (Forwarding) state with the "DESG" (Designated) role. In a Spanning Tree topology, the root bridge is the only device where all active participating interfaces serve as designated ports, as it has no need for a "Root" port role (which points toward a root bridge).
The second correct statement is that the bridge priority for switch1 is 32k (Option D). Looking at the "Designated bridge ID" column, we see the value 32768.0019e2552481. In Junos and general networking standards, the Bridge ID is composed of a bridge priority and the device's MAC address. The default priority for most Spanning Tree variants (STP, RSTP, MSTP) is 32, 768, which is commonly referred to in shorthand as "32k".
Regarding the incorrect options:
Option A: There is no evidence of VSTP (VLAN Spanning Tree Protocol) ; the output shows "instance 0, " which is typical for IEEE standard RSTP or STP.
Option C: The Port IDs for ge-0/0/8, ge-0/0/9, and ge-0/0/11 all start with "32" (e.g., 32: 521), whereas the default port priority is typically 128 (as seen in ge-0/0/6.0 with 128: 519). This indicates that the interface priorities for these specific ports have been manually tuned to a non-default value.
정답:
Explanation:
In the Border Gateway Protocol (BGP) finite state machine (FSM), the Established state is the final and functional stage of a BGP peering session. According to Juniper Networks technical documentation, once a session reaches this state, the two peers have successfully exchanged Open messages and agreed upon session parameters (such as AS numbers, hold timers, and BGP identifiers). Only after the session is "Established" can the routers begin the actual exchange of network layer reachability information (NLRI).
The most frequent message type exchanged in the Established state is the UPDATE message. These messages are the heart of BGP operations; they are used to advertise new feasible routes to a peer or to withdraw routes that are no longer reachable. An UPDATE message contains path attributes (like AS-Path, Next-Hop, and Local Preference) and the associated prefixes. In a stable network, UPDATE messages are only sent when there is a change in the topology, adhering to BGP’s incremental update philosophy.
The second message type that can be exchanged in this state is the NOTIFICATION message. While ideally, a session stays established, any detected error―such as a hold timer expiration, a malformed update, or a manual "clear" command―will trigger the transmission of a NOTIFICATION message. This message informs the peer of the specific error code and immediately causes the BGP session to transition back to the Idle state, tearing down the TCP connection.
It is important to note that OPEN messages (Option A) are only used during the session initialization phase to transition from the Open Confirm state to Established. REQUEST (Option B) is not a valid BGP message type defined in the standard (RFC 4271) ; the closest equivalent in functionality would be a Route-Refresh message, which is a separate extension. Therefore, in the context of standard BGP operations within the Established state, Updates and Notifications are the correct answers.
정답:
Explanation:
In the Junos OS architecture, route preference (often referred to as administrative distance in other vendor platforms) is the primary metric used by the Routing Engine to select the "best" path when multiple protocols provide a route to the same destination. Each routing protocol and route type is assigned a default numeric value; the lower the value, the more preferred the route.
According to Juniper Networks technical documentation, an aggregate route is assigned a default preference of 130. Aggregate routes are a form of static-like route used to group specific routes into a single, broader prefix to reduce the size of routing tables and limit the scope of routing updates. They are "protocol-independent" because they are not learned from a dynamic neighbor but are manually defined by the administrator.
To understand where130fits in the hierarchy, it is helpful to compare it with other common Junos preferences:
Directly connected interfaces: 0
Static routes: 5
OSPF Internal: 10
IS-IS Level 1/2: 15/18
Aggregate routes: 130
OSPF AS External: 150
BGP (Internal and External): 170
Generated routes: 150
By setting the aggregate route preference to 130, Junos ensures that specific routes learned via IGPs (like OSPF or IS-IS) are preferred over the aggregate. This is essential because an aggregate route is often used as a "catch-all" or a discard route when more specific path information is missing. If the aggregate had a lower preference (like 5), it might override dynamic routing information, leading to suboptimal routing or black-holed traffic.
정답:
Explanation:
The prevention of routing loops within an Autonomous System (AS) is handled differently than loop prevention between ASes. While External BGP (EBGP) uses the AS_PATH attribute to detect loops, Internal BGP (IBGP) does not modify the AS_PATH. Therefore, a different mechanism is required to ensure that a route does not circulate infinitely inside the network.
This mechanism is known as the IBGP Split Horizon rule. According to Juniper Networks documentation and the BGP standard (RFC 4271), a BGP speaker must not advertise a route learned via an IBGP peer to any other IBGP peer. In simpler terms, "what is learned internally, stays local." This rule ensures that a route only travels one "hop" inside the AS―from the router that learned it from an external source to all other internal routers.
Because of this rule, IBGP routers do not naturally propagate routes through each other. This creates a requirement for a full mesh of IBGP sessions, where every BGP-speaking router in the AS must have a direct peering session with every other BGP-speaking router. To mitigate the scaling issues of a full mesh in large service provider networks, architects use Route Reflectors or Confederations, which are authorized exceptions to the Split Horizon rule.
Option B is incorrect because EBGP peers do advertise EBGP routes to other EBGP peers (this is how the internet works).
Option C is incorrect because EBGP-learned routes must be sent to IBGP peers so the internal network knows how to reach the outside world.
Option D is incorrect because internal routes must be sent to external peers to advertise your network to the internet.
정답:
Explanation:
In the context of Juniper Networks High Availability, Bidirectional Forwarding Detection (BFD) is a lightweight protocol designed to provide fast failure detection for the forwarding path. Unlike the slow "hello" mechanisms found in IGPs like OSPF or IS-IS, BFD can detect link or neighbor failures in sub-second intervals.
According to Juniper Networks technical documentation, BFD operates through a negotiation process. When two routers establish a BFD session, they exchange their locally configured Minimum Transmit Interval and Minimum Receive Interval within the BFD control packets. The fundamental rule of BFD negotiation is that the routers must agree on a common timing value that accommodates the slower of the two devices to ensure stability and prevent "false positives" (detecting a failure when none exists simply because one router cannot keep up with the processing speed).
In this scenario, R1 expects to send at 300ms, while R2 is configured for 400ms. During the handshake, R1 informs R2 it is capable of 300ms, but R2 informs R1 it can only support a minimum of 400ms. Consequently, the routers will negotiate to use the slowest of the two rates (400ms). Specifically, the transmission interval of one router is matched to the receive interval of the other. By choosing the highest common denominator (the slowest rate), the BFD session ensures that both routers have sufficient time to process incoming control packets. This negotiation allows BFD to be highly flexible in heterogeneous environments where different hardware platforms may have varying CPU capabilities for handling rapid heartbeat packets.
정답:
Explanation:
In Junos OS, understanding the distinction between the Routing Information Base (RIB) and the Forwarding Information Base (FIB) is fundamental to analyzing traffic patterns and load-balancing behavior. The RIB (show route) contains all prefixes learned via various protocols, while the FIB (show route forwarding-table) contains only the active next-hops that are actually programmed into the Packet Forwarding Engine (PFE).
According to Juniper Networks technical documentation, the default behavior for Junos OS when encountering Equal-Cost Multipath (ECMP) routes is to select only a single next-hop from the available candidates in the RIB and install that single path into the FIB. In a default state, even if the show route output displays multiple next-hops for a destination like 172.24.0.0/24, only one would have the active route symbol ( >) and only that one would appear in the forwarding table.
In the provided exhibit, the show route output shows two next-hops for 172.24.0.0/24, but only the first one (172.20.0.2) is marked with the>symbol as the active selection. However, the subsequent show route forwarding-table output reveals that both next-hops (172.20.0.2 and 172.20.1.2) are currently present in the forwarding table for that same destination. This discrepancy indicates that the default load-balancing behavior has been modified (Option B). This modification is typically achieved by creating a routing policy with the action then load-balance per-packet (which actually results in flow-based load balancing) and applying it to the forwarding table via the export statement under [edit routing-options forwarding-table].
Because the forwarding table now contains both next-hops, the router is no longer restricted to a single path. Therefore, the router will choose both next-hops in the routing table (Option D) for packet forwarding, distributing flows across the two available Gigabit Ethernet interfaces (ge-0/0/2.0 and ge-0/0/3.0). This ensures higher utilized bandwidth and provides redundancy at the data plane level.