You are troubleshooting a Level 1 IS-IS router that has an adjacency with a Level 1/2 router. Which two statements are correct in this scenario? (Choose two.)
Answer(s): C,D
In the context of Juniper Networks Junos OS and the IS-IS (Intermediate System to Intermediate System) protocol, understanding the hierarchical relationship between router levels is critical for effective troubleshooting and design. IS-IS uses a two-level hierarchy to manage scalability: Level 1 (L1), which represents intra-area routing, and Level 2 (L2), which represents inter-area backbone routing.When a router is configured as a Level 1/2 (L1/L2) device, it acts as a bridge between the two levels. According to Juniper technical documentation, an L1/L2 router maintains two completely separate Link-State Databases (LSDB)—one for Level 1 and one for Level 2. It does not merge these into a single topology. This separation ensures that local area topology changes (L1) do not necessarily flood into the backbone (L2) unless specific redistribution is configured, and vice versa. Therefore, statement C is correct because the L1/L2 router maintains distinct SPF (Shortest Path First) computations for each level.Regarding the visibility of the Level 1 router, IS-IS is designed to keep L1 areas "stubby" by default. A Level 1 router only possesses the topology information for its own area (the Level 1 LSDB). It does not receive specific L2 routes or the L2 topology. Instead, the L1/L2 router sets the Attached (ATT) bit in its L1 Link-State PDUs (LSPs) to signal to L1-only routers that it has a connection to the backbone. The L1 router then generates a default route pointing to the L1/L2 router to reach inter-area destinations. This confirms that statement D is correct: the L1 router's knowledge is limited to its local L1 topology.Conversely, statements A and B are incorrect because merging topologies would violate the hierarchical scaling principles of IS-IS, and L1 routers never learn the full L2 topology without explicit, non-standard route leaking.
By default, which routing table contains a list of all ingress LSPs?
Answer(s): B
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.The inet.3 routing 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.0 is the default unicast routing table used for standard IPv4 forwarding and contains routes learned via IGPs (OSPF, IS-IS) or static routing. inet.1 is utilized for multicast forwarding (MBGP), and inet.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.
What are two types of BGP messages exchanged while in the Established state? (Choose two.)
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 OpenConfirm 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.
What is the default route preference for an aggregate route?
Answer(s): C
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 where 130 fits in the hierarchy, it is helpful to compare it with other common Junos preferences:Directly connected interfaces: 0Static routes: 5OSPF Internal: 10IS-IS Level 1/2: 15/18Aggregate routes: 130OSPF AS External: 150BGP (Internal and External): 170Generated routes: 150By 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.
What information is determined by using the AS path attribute included in the BGP update message? (Choose two.)
Answer(s): B,C
The AS_PATH attribute is a "well-known mandatory" attribute in BGP, meaning it must be present in every BGP Update message exchanged between External BGP (eBGP) peers. It records the sequence of Autonomous System numbers that a route has traversed. Per Juniper Networks Service Provider documentation, this attribute serves two fundamental purposes:1. Loop Prevention (Option B):This is the most critical function of the AS_PATH. When a BGP router receives an update from an eBGP peer, it scans the AS_PATH attribute for its own AS number. If the router finds its local AS number already listed in the path, it concludes that the route has already passed through its network and has "looped" back. To prevent an infinite routing loop, the router will immediately discard the update. This mechanism is the cornerstone of BGP's stability as a path-vector protocol.2. Path Selection / Shortest Path Determination (Option C):BGP uses a complex "tie-breaking" algorithm to select the best path among multiple candidates. One of the highest-ranking criteria in this algorithm (after Weight, Local Preference, and AS_PATH length) is the length of the AS_PATH. A shorter AS_PATH (fewer AS numbers listed) is generally preferred over a longer one, as it typically represents a more direct path through the internet hierarchy.Why other options are incorrect:Option A: The "origin" of a route (IGP, EGP, or Incomplete) is determined by the ORIGIN attribute, which is a separate well-known mandatory attribute.Option D: BGP does not count individual "next-hop devices" (which would be an IGP metric like hop count in RIP); it only tracks Autonomous Systems. A single AS in the path might contain hundreds of internal routers (next-hops), but BGP only sees it as one "hop" in the AS_PATH.
During OSPF neighbor establishment, which packet type is used to describe the contents of the link-state database?
In the OSPF (Open Shortest Path First) protocol, ensuring that all routers within an area have a synchronized Link-State Database (LSDB) is fundamental to building a consistent loop-free topology. During the adjacency formation process—specifically when transitioning from the ExStart state to the Exchange state—routers must determine what information they are missing from their neighbors without sending the entire database at once, which would be highly inefficient.The Database Description (DBD) packet, also known as a DDP, is the mechanism used for this summary exchange. According to Juniper Networks technical documentation, the DBD packet does not contain full Link-State Advertisements (LSAs). Instead, it contains only the LSA headers, which include the LSA type, the ID of the advertising router, and the sequence number.By exchanging these headers, a Juniper router can compare the neighbor's database summary against its own local LSDB. If the router identifies a header in the DBD packet that represents a newer or missing entry, it records that LSA in its "Link-State Request List." This collaborative "handshake" ensures that only the necessary, updated information is requested in the subsequent Link-State Request (LSR) phase. It is important to distinguish this from the Link-State PDU (LSP) mentioned in Option D, which is actually the term used in the IS-IS protocol, not OSPF. In OSPF, the functional unit is the LSA, and the transport vehicle for the initial summary is the DBD packet. This methodical synchronization is what allows OSPF to scale effectively in large service provider environments.
Which OSPF packet type is used to initiate and maintain neighbor relationships?
Answer(s): A
The Hello packet is the most basic, yet most vital, component of the OSPF protocol. It serves as the primary mechanism for neighbor discovery, parameter negotiation, and "keepalive" functionality. Per Juniper Networks' routing documentation, OSPF routers use the Hello protocol to dynamically discover other OSPF-enabled routers on their directly connected segments.When OSPF is enabled on a Junos interface, the router begins multicasting Hello packets (typically to the 224.0.0.5 "All OSPF Routers" address). This initiates the neighbor relationship. For two routers to move beyond the Init state and become neighbors, they must agree on several critical parameters contained within the Hello packet:Area ID: Routers must be in the same OSPF area.Authentication: Passwords or keys must match.Timers: The Hello and Dead intervals must be identical.Options: Such as Stub area flags.Beyond the initial "initiation," the Hello packet is used to maintain the relationship. By continuously sending these packets at a fixed interval (the Hello interval), a router signals to its peers that it is still functional. If a router stops receiving Hello packets from a neighbor for a duration exceeding the Dead Interval, it declares the neighbor "down," flushes the associated LSAs from the database, and triggers a new SPF calculation.Furthermore, on multi-access networks like Ethernet, the Hello packet is the vehicle for the election of the Designated Router (DR) and Backup Designated Router (BDR). By exchanging priority values and Router IDs within the Hello packets, the segment can elect a central point of contact to minimize the number of adjacencies required on the wire.
What prevents routing loops in a single-area OSPF network?
In OSPF, loop prevention within a single area is achieved through the fundamental nature of its link-state architecture. Unlike distance-vector protocols that rely on "routing by rumor," OSPF ensures that every router within an area maintains an identical Link-State Database (LSDB). This database acts as a complete map of the network topology.Once the LSDB is synchronized, each router independently executes the Shortest Path First (SPF) algorithm, which is formally known as the Dijkstra algorithm. This mathematical process treats the local router as the "root" of a tree and calculates the shortest path to every other node (router) and prefix in the area based on the cumulative interface costs. Because every router uses the same synchronized map (the LSDB) and the same deterministic algorithm, they all arrive at a consistent, loop-free view of the best paths.According to Juniper Networks technical documentation, the Dijkstra algorithm is superior to the Bellman-Ford algorithm (used by distance-vector protocols like RIP) in this regard. Bellman-Ford is susceptible to "count-to-infinity" problems and loops because routers only know the distance and direction to a destination provided by their neighbors, rather than the full topology. In OSPF, even if a link fails, the updated Link-State Advertisement (LSA) is flooded rapidly, and the Dijkstra algorithm is re-run to find a new loop-free path. Routing policies (Option B) are used to manipulate path selection or filter routes but are not the primary mechanism for fundamental loop prevention in OSPF. Similarly, forwarding policies (Option D) govern how traffic is handled at the data plane level rather than determining the control plane's loop-free topology.
Share your comments for Juniper JN0-364 exam with other users:
its my first time exam
correct answers are device configuration-enable the automatic installation of webview2 runtime. & policy management- prevent users from submitting feedback.
is this dump still valid? today is 9-july-2023
i need this exam.. please upload these are really helpful
please upload the oracle 1z0-1059-22 dumps
very good questions
nice, first step to exams
is this valid for chfiv9 as well... as i am reker 3rd time...
great exam for people taking 220-1101
this is very helpfull for me
just started preparing for the exam
these are the type of questions i need.
does this actually work? are they the exam questions and answers word for word?
thanks for providing these questions
interesting
these dumps are pretty good.
good questions
dbua is used for upgrading oracle database
i am thrilled to say that i passed my amazon web services mls-c01 exam, thanks to study materials. they were comprehensive and well-structured, making my preparation efficient.
please upload latest ibm ace c1000-056 dumps
if only explanations were provided...
yes .. i need the dump if you can help me
good morning, could you please upload this exam again?
hi please upload sre foundation and practitioner exam questions
the exam is listed as 80 questions with a pass mark of 70%, how is your 50 questions related?
all questions are so important and covers all ccna modules
q 44. ans:- b (goto setup > order settings > select enable optional price books for orders) reference link --> https://resources.docs.salesforce.com/latest/latest/en-us/sfdc/pdf/sfom_impl_b2b_b2b2c.pdf(decide whether you want to enable the optional price books feature. if so, select enable optional price books for orders. you can use orders in salesforce while managing price books in an external platform. if you’re using d2c commerce, you must select enable optional price books for orders.)
"cost of replacing data if it were lost" is also correct.
pls upload the questions
question 182 - correct answer is d. ethernet frame length is 64 - 1518b. length of user data containing is that frame: 46 - 1500b.
i need this exam pls
its required for me, please make it enable to access. thanks
seems good..