A fully updated 2025 JN0-664 Exam Dumps exam guide from training expert Actual4Labs
Provides complete coverage of every objective on exam and exam preparation JN0-664
Juniper JN0-664 certification exam is a professional-level certification exam designed for service provider network engineers who want to validate their knowledge and expertise in the field. Service Provider, Professional (JNCIP-SP) certification exam covers a wide range of topics related to service provider network operations and management, including routing protocols, MPLS, QoS, Layer 2 and Layer 3 VPNs, network security, and more.
NEW QUESTION # 26
Which two statements about IS-IS are correct? (Choose two.)
- A. CSNPs contain only descriptions of LSPs.
- B. CSNPs are flooded periodically.
- C. PSNPs are flooded periodically.
- D. PSNPs contain only descriptions of LSPs.
Answer: B,D
NEW QUESTION # 27
Exhibit
A network designer would like to create a summary route as shown in the exhibit, but the configuration is not working.
Which three configuration changes will create a summary route? (Choose three.)
- A. set protocols isis import summary-v6
- B. delete protocols isis export summary-v6
- C. set policy-options policy-statement leak-v6 term DC-routes from route-filter 2001:db9:a:faOO::/61 exact
- D. delete policy-options policy-statement leak-v6 term DC-routes from route-filter 2001: db9 :a: fa00 : :/6l longer
- E. set policy-options policy-statement leak-v6 term DC-routes then reject
Answer: B,C,D
Explanation:
To create a summary route for IS-IS, you need to configure a policy statement that matches the prefixes to be summarized and sets the next-hop to discard. You also need to configure a summary-address statement under the IS-IS protocol hierarchy that references the policy statement. In this case, the policy statement leak-v6 is trying to match the prefix 2001:db9:a:fa00::/61 exactly, but this prefix is not advertised by any router in the network. Therefore, no summary route is created. To fix this, you need to delete the longer keyword from the route-filter term and change the prefix length to /61 exact. This will match any prefix that falls within the /61 range. You also need to delete the export statement under protocols isis, because this will export all routes that match the policy statement to other IS-IS routers, which is not desired for a summary route.
NEW QUESTION # 28
You are a network architect for a service provider and want to offer Layer 2 services to your customers. You want to use EVPN for Layer 2 services in your existing MPLS network.
Which two statements are correct in this scenario? (Choose two.)
- A. Segment routing must be configured on all PE routers.
- B. VXLAN must be configured on all PE routers.
- C. EVPN uses Type 3 routes to join a multicast tree to flood traffic.
- D. EVPN uses Type 2 routes to advertise MAC address and IP address pairs learned using ARP snooping.
Answer: C,D
NEW QUESTION # 29
Exhibit
Referring to the exhibit, which two statements are true? (Choose two.)
- A. The device advertising this route into EVPN is 192.168.101.5.
- B. This route is learned through EBGP
- C. This is an EVPN Type-2 route.
- D. The devices advertising this route into EVPN are 10 0 2 12 and 10.0.2.22.
Answer: A,C
Explanation:
This is an EVPN Type-2 route, also called a MAC/IP advertisement route, that is used to advertise host IP and MAC address information to other VTEPs in an EVPN network. The route type field in the EVPN NLRI has a value of 2, indicating a Type-2 route. The device advertising this route into EVPN is 192.168.101.5, which is the IP address of the VTEP that learned the host information from the local CE device. This IP address is carried in the MPLS label field of the route as part of the VXLAN encapsulation.
NEW QUESTION # 30 
Click the Exhibit button.
You have an EVI implemented between PE-1, PE-2, and PE-3 to allow communication between CE-1 and CE-
2. CE-2 receives unicast traffic from CE-1 on both links to PE-2 and
PE-3. When CE-1 sends broadcast traffic, CE-2 receives it on only one of the multihomed links.
Referring to the exhibit, which EVPN route type enables this behavior?
- A. Type 1
- B. Type 3
- C. Type 4
- D. Type 2
Answer: B
Explanation:
In the context of Ethernet VPN (EVPN) and the behavior described in the exhibit, it's essential to understand the different EVPN route types and their specific functionalities. Here, CE-2 is receiving unicast traffic on both of its multihomed links to PE-2 and PE-3, but broadcast traffic is received only on one of these links.
**Explanation of EVPN Route Types**:
1. **Type 1 (Ethernet Auto-Discovery Routes)**:
- These routes are used for auto-discovery of Ethernet segments and for advertising VLAN membership.
- They do not directly influence the behavior described in the question.
2. **Type 2 (MAC/IP Advertisement Routes)**:
- These routes are used to advertise MAC addresses and IP-to-MAC bindings within the EVPN.
- They handle unicast traffic forwarding and are crucial for populating the MAC address tables on the PE devices.
- While important, they do not explain the selective broadcast behavior.
3. **Type 3 (Inclusive Multicast Ethernet Tag Routes)**:
- These routes are used to build multicast distribution trees for delivering broadcast, unknown unicast, and multicast (BUM) traffic.
- They ensure that BUM traffic is sent only once per Ethernet segment, preventing duplicate frames from being sent to multihomed CEs.
- This aligns with the behavior described where CE-2 receives broadcast traffic on only one link to prevent duplication.
4. **Type 4 (Ethernet Segment Routes)**:
- These routes are used to advertise the presence of an Ethernet segment and are crucial for Designated Forwarder (DF) election processes in multihoming scenarios.
- While relevant to multihoming, they are not directly responsible for the selective broadcast behavior.
**Conclusion**:
The behavior described, where CE-2 receives broadcast traffic on only one of its multihomed links, is controlled by Type 3 routes. These routes are specifically designed to handle inclusive multicast and broadcast traffic efficiently in EVPN environments, ensuring that such traffic is not duplicated across multiple links to the same CE.
**References**:
- Juniper Networks EVPN Documentation: [EVPN Overview](https://www.juniper.net/documentation/en_US
/junos/topics/concept/evpn-overview.html)
- RFC 7432, BGP MPLS-Based Ethernet VPN: [RFC 7432](https://tools.ietf.org/html/rfc7432) provides detailed descriptions of EVPN route types and their functions.
- Junos OS EVPN Configuration Guide: [Junos OS EVPN Configuration Guide](https://www.juniper.net
/documentation/en_US/junos/topics/topic-map/evpn.html)
NEW QUESTION # 31
Exhibit
You want Site 1 to access three VLANs that are located in Site 2 and Site 3 The customer-facing interface on the PE-1 router is configured for Ethernet-VLAN encapsulation.
What is the minimum number of L2VPN routing instances to be configured to accomplish this task?
- A. 0
- B. 1
- C. 2
- D. 3
Answer: A
Explanation:
Explanation
To allow Site 1 to access three VLANs that are located in Site 2 and Site 3, you need to configure three L2VPN routing instances on PE-1, one for each VLAN. Each L2VPN routing instance will have a different VLAN ID and a different VNI for VXLAN encapsulation. Each L2VPN routing instance will also have a different vrf-target export value to identify which VPN routes belong to which VLAN. This way, PE-1 can forward traffic from Site 1 to Site 2 and Site 3 based on the VLAN tags and VNIs.
NEW QUESTION # 32
Exhibit
A network is using IS-IS for routing.
In this scenario, why are there two TLVs shown in the exhibit?
- A. The interface specified a metric of 100 for L2.
- B. There are both narrow and wide metric devices in the topology
- C. Both IPv4 and IPv6 are being used in the topology
- D. Wide metrics have specifically been requested
Answer: B
Explanation:
TLVs are tuples of (Type, Length, Value) that can be advertised in IS-IS packets. TLVs can carry different kinds of information in the Link State Packets (LSPs). IS-IS supports both narrow and wide metrics for link costs. Narrow metrics use a single octet to encode the link cost, while wide metrics use three octets. Narrow metrics have a maximum value of 63, while wide metrics have a maximum value of 16777215. If there are both narrow and wide metric devices in the topology, IS-IS will advertise two TLVs for each link: one with the narrow metric and one with the wide metric. This allows backward compatibility with older devices that only support narrow metrics12.
NEW QUESTION # 33
After a recent power outage, your manager asks you to investigate ways to automatically reduce the impact caused by suboptimal routing in your OSPF and OSPFv3 network after devices reboot.
Which three configuration statements accomplish this task? (Choose three.)
- A. set protocols ospf overload timeout 900
- B. set protocols ospf3 overload
- C. set protocols ospf3 realm ipv4-unicast overload timeout 900
- D. set protocols ospf overload
- E. set protocols oapf3 overload timeout 900
Answer: A,B
Explanation:
Explanation
To reduce the impact of suboptimal routing in OSPF and OSPFv3 after devices reboot, you can use the overload feature to prevent a router from being used as a transit router for a specified period of time. This allows the router to stabilize its routing table before forwarding traffic for other routers. To enable the overload feature, you need to do the following:
* For OSPF, configure the overload statement under [edit protocols ospf] hierarchy level. You can also specify a timeout value in seconds to indicate how long the router should remain in overload state after it boots up. For example, set protocols ospf overload timeout 900 means that the router will be in overload state for 15 minutes after it boots up.
* For OSPFv3, configure the overload statement under [edit protocols ospf3] hierarchy level. You can also specify a realm (ipv4-unicast or ipv6-unicast) and a timeout value in seconds to indicate how long the router should remain in overload state after it boots up for each realm. For example, set protocols ospf3 realm ipv4-unicast overload timeout 900 means that the router will be in overload state for 15 minutes after it boots up for IPv4 unicast routing.
NEW QUESTION # 34
Exhibit
CE-1 must advertise ten subnets to PE-1 using BGP Once CE-1 starts advertising the subnets to PE-1, the BGP peering state changes to Active.
Referring to the CLI output shown in the exhibit, which statement is correct?
- A. The prefix limit has been reached on PE-1
- B. CE-1 is configured with an incorrect peer AS
- C. CE-1 is unreachable
- D. CE-1 is advertising its entire routing table.
Answer: B
Explanation:
The problem in this scenario is that CE-1 is configured with an incorrect peer AS number for its BGP session with PE-1. The CLI output shows that CE-1 is using AS 65531 as its local AS number and AS 65530 as its peer AS number. However, PE-1 is using AS 65530 as its local AS number and AS 65531 as its peer AS number. This causes a mismatch in the BGP OPEN messages and prevents the BGP session from being established. To solve this problem, CE-1 should configure its peer AS number as 65530 under [edit protocols bgp group external] hierarchy level.
NEW QUESTION # 35
Exhibit
CE-1 and CE-2 are part of a VPLS called Customer1 No connectivity exists between CE-1 and CE-2. In the process of troubleshooting, you notice PE-1 is not learning any routes for this VPLS from PE-2, and PE-2 is not learning any routes for this VPLS from PE-1.
- A. The no-tunnel-services statement should be deleted on both PEs.
- B. The route distinguisher must match on PE-1 and PE-2.
- C. The route target must match on PE-1 and PE-2.
- D. The instance type should be changed to I2vpn.
Answer: C
Explanation:
VPLS is a technology that provides Layer 2 VPN services over an MPLS network. VPLS uses BGP as its control protocol to exchange VPN membership information between PE routers. The route target is a BGP extended community attribute that identifies which VPN a route belongs to. The route target must match on PE routers that participate in the same VPLS instance, otherwise they will not accept or advertise routes for that VPLS.
NEW QUESTION # 36
Which two statements are correct about VPLS tunnels? (Choose two.)
- A. BGP-signaled VPLS tunnels require manual provisioning of sites.
- B. LDP-signaled VPLS tunnels only support control bit 0.
- C. LDP-signaled VPLS tunnels use auto-discovery to provision sites.
- D. BGP-signaled VPLS tunnels can use either RSVP or LDP between the PE routers.
Answer: B,D
NEW QUESTION # 37
Exhibit
Based on the configuration contents shown in the exhibit, which statement is true?
- A. Joins for group 224.7.7.7 are rejected if the source address is 192.168.100.10
- B. Joins for group 224.7.7.7 are accepted if the group count is less than 25
- C. Joins for any group are accepted if the group count value is less than 25.
- D. Joins for group 224.7.7.7 are always rejected, regardless of the group count.
Answer: B
Explanation:
Explanation
BGP policy framework is a set of tools that allows you to control the flow of routing information and apply routing policies based on various criteria. BGP policy framework consists of several components, such as route maps, prefix lists, community lists, AS path lists, and route filters. Route maps are used to define routing policies by matching certain conditions and applying certain actions. Prefix lists are used to filter routes based on their prefixes. Community lists are used to filter routes based on their community attributes. AS path lists are used to filter routes based on their AS path attributes. Route filters are used to filter routes based on their prefix length or range3. In this question, we have a route map named ISP-A that has two clauses: clause 10 and clause 20. Clause 10 matches any route with a prefix length between 8 and 24 bits and sets the local preference to 200. Clause 20 matches any route with a prefix of 224.7.7.7/32 and rejects it. The route map is applied inbound on the BGP neighborship with ISP-A. Based on this configuration, the correct statement is that joins for group 224.7.7.7 are always rejected, regardless of the group count. This is because clause 20 explicitly denies any route with a prefix of 224.7.7.7/32, which corresponds to the multicast group 224.7.7.7.
NEW QUESTION # 38
Exhibit
R1 and R8 are not receiving each other's routes
Referring to the exhibit, what are three configuration commands that would solve this problem? (Choose three.)
- A. Configure loops on routers in AS 65412 and advertise-peer-as on routers in AS 64498.
- B. Configure remove-private on advertisements from AS 64497 toward AS 64498
- C. Configure as-override on advertisement from AS 64500 toward AS 64512.
- D. Configure remove-private on advertisements from AS 64500 toward AS 64499
- E. Configure loops and advertise-peer-as on routers in AS 64497 and AS 64450.
Answer: A,B,D
Explanation:
The problem in this scenario is that R1 and R8 are not receiving each other's routes because of private AS numbers in the AS path. Private AS numbers are not globally unique and are not advertised to external BGP peers. To solve this problem, you need to do the following:
* Configure loops on routers in AS 65412 and advertise-peer-as on routers in AS 64498. This allows R5 and R6 to advertise their own AS number (65412) instead of their peer's AS number (64498) when sending updates to R7 and R8. This prevents a loop detection issue that would cause R7 and R8 to reject the routes from R5 and R62.
* Configure remove-private on advertisements from AS 64497 toward AS 64498 and from AS 64500
* toward AS 64499. This removes any private AS numbers from the AS path before sending updates to external BGP peers. This allows R2 and R3 to receive the routes from R1 and R4, respectively3.
NEW QUESTION # 39
Exhibit
Click the Exhibit button-Referring to the exhibit, which two statements are correct about BGP routes on R3 that are learned from the ISP-A neighbor? (Choose two.)
- A. The next-hop value for these routes is changed by ISP-A before being sent to R3.
- B. By default, the next-hop value for these routes is not changed by ISP-A before being sent to R3.
- C. The BGP local-preference value that is used by ISP-A is not advertised to R3.
- D. All BGP attribute values must be removed before receiving the routes.
Answer: A,C
Explanation:
Analyzing the Exhibit
* The diagram represents BGP peering between:
* AS 65512 (Enterprise Network)
* AS 65511 (ISP-A)
* R3 and R4 are peering with ISP-A using EBGP.
* R1, R2, R3, and R4 are peering within AS 65512 using IBGP.
Understanding BGP Route Behavior
Option A: "By default, the next-hop value for these routes is not changed by ISP-A before being sent to R3." #
* Incorrect!
* EBGP behavior: When a BGP route is advertised via EBGP, the next-hop IP is changed to the router's own IP by default.
* Since ISP-A is advertising routes via EBGP to R3, the next-hop is changed to ISP-A's IP.
* Thus, this statement is incorrect.
Option B: "The BGP local-preference value that is used by ISP-A is not advertised to R3." #
* Correct!
* BGP Local Preference (LOCAL_PREF) is an IBGP-only attribute.
* Local Preference is NOT shared over EBGP because it is used within an AS to influence route selection.
* ISP-A will not send LOCAL_PREF to R3, as R3 is in a different AS.
* Thus, this statement is correct.
Option C: "All BGP attribute values must be removed before receiving the routes." #
* Incorrect!
* BGP does not remove all attributes when advertising routes. Some attributes are modified (e.g., next- hop, AS-PATH), but others (like MED, community) may be preserved.
* Thus, this statement is incorrect.
Option D: "The next-hop value for these routes is changed by ISP-A before being sent to R3." #
* Correct!
* As per default EBGP behavior, the next-hop is changed when a route is advertised to an EBGP peer.
* This means ISP-A changes the next-hop to its own IP before sending it to R3.
* Thus, this statement is correct.
# B. The BGP local-preference value that is used by ISP-A is not advertised to R3.
# D. The next-hop value for these routes is changed by ISP-A before being sent to R3.
Verification from Juniper Documentation:
* Juniper BGP Configuration Guide confirms that LOCAL_PREF is not advertised over EBGP.
* RFC 4271 (BGP-4) specifies that next-hop is changed by default when advertising routes via EBGP
.
NEW QUESTION # 40
Exhibit
You are running a service provider network and must transport a customer's IPv6 traffic across your IPv4-based MPLS network using BGP You have already configured mpis ipv6-tunneling on your PE routers.
Which two statements are correct about the BGP configuration in this scenario? (Choose two.)
- A. You must configure family inet6 unicast between PE routers.
- B. You must configure family inet6 add-path between PE and CE routers.
- C. You must configure family inet6 labeled-unicast between PE routers.
- D. You must configure family inet6 unicast between PE and CE routers.
Answer: C,D
Explanation:
To transport IPv6 traffic over an IPv4-based MPLS network using BGP, you need to configure two address families: family inet6 labeled-unicast and family inet6 unicast. The former is used to exchange IPv6 routes with MPLS labels between PE routers, and the latter is used to exchange IPv6 routes without labels between PE and CE routers. The mpis ipv6-tunneling command enables the PE routers to encapsulate the IPv6 packets with an MPLS label stack and an IPv4 header before sending them over the MPLS network.
NEW QUESTION # 41
Exhibit
Which two statements about the output shown in the exhibit are correct? (Choose two.)
- A. The connection has not flapped since it was initiated.
- B. There has been a VLAN ID mismatch.
- C. The PE is attached to a single local site.
- D. The PE router has the capability to pop flow labels
Answer: A,C
Explanation:
The output is from the show l2vpn connections command on a Juniper router. This command is used to verify the status of Layer 2 VPN (L2VPN) pseudowires between Provider Edge (PE) routers.
Breakdown of Key Information:
* Instance: vpn-A
* This is the L2VPN instance being monitored.
* Connection Status (St)
* The connection status is "Up", meaning the pseudowire is operational.
* Local Site: CE1-2 (2)
* The PE router is attached to a single local site (CE1-2).
* Uptime & Connection Flaps
* The output shows the last time the connection was up:
Time last up: Apr 11 14:35:27 2020
* The "# Up trans" value is 1, meaning this connection has been established once and has not flapped since it was initiated.
* VLAN ID Mismatch Check
* The legend includes "VM - VLAN ID mismatch", but this status is not present in the connection output.
* This means there is NO VLAN ID mismatch.
* Flow Labels
* The Flow Label Transmit is No, and the Flow Label Receive is No.
* This means the PE router does NOT have the capability to pop flow labels.
NEW QUESTION # 42
Exhibit
user@Rl show configuration interpolated-profile { interpolate {
fill-level [ 50 75 drop-probability [ > }
class-of-service drop-profiles
];
20 60 ];
Which two statements are correct about the class-of-service configuration shown in the exhibit? (Choose two.)
- A. To use this drop profile, you reference it in a scheduler.
- B. To use this drop profile, you apply it directly to an interface.
- C. The drop probability jumps immediately from 20% to 60% when the queue level reaches 75% full.
- D. The drop probability gradually increases from 20% to 60% as the queue level increases from 50% full to
75% full
Answer: A,D
Explanation:
class-of-service (CoS) is a feature that allows you to prioritize and manage network traffic based on various criteria, such as application type, user group, or packet loss priority. CoS uses different components to classify, mark, queue, schedule, shape, and drop traffic according to the configured policies.
One of the components of CoS is drop profiles, which define how packets are dropped when a queue is congested. Drop profiles use random early detection (RED) algorithm to drop packets randomly before the queue is full, which helps to avoid global synchronization and improve network performance. Drop profiles can be discrete or interpolated. A discrete drop profile maps a specific fill level of a queue to a specific drop probability. An interpolated drop profile maps a range of fill levels of a queue to a range of drop probabilities and interpolates the values in between.
In the exhibit, we can see that the class-of-service configuration shows an interpolated drop profile with two fill levels (50 and 75) and two drop probabilities (20 and 60). Based on this configuration, we can infer the following statements:
* The drop probability jumps immediately from 20% to 60% when the queue level reaches 75% full. This is not correct because the drop profile is interpolated, not discrete. This means that the drop probability gradually increases from 20% to 60% as the queue level increases from 50% full to 75% full. The drop probability for any fill level between 50% and 75% can be calculated by using linear interpolation formula.
* The drop probability gradually increases from 20% to 60% as the queue level increases from 50% full to
75% full. This is correct because the drop profile is interpolated and uses linear interpolation formula to calculate the drop probability for any fill level between 50% and 75%. For example, if the fill level is
60%, the drop probability is 28%, which is calculated by using the formula: (60 - 50) / (75 - 50) * (60 -
20) + 20 = 28.
* To use this drop profile, you reference it in a scheduler. This is correct because a scheduler is a
* component of CoS that determines how packets are dequeued from different queues and transmitted on an interface. A scheduler can reference a drop profile by using the random-detect statement under the
[edit class-of-service schedulers] hierarchy level. For example: scheduler test { transmit-rate percent 10; buffer-size percent 10; random-detect test-profile; }
* To use this drop profile, you apply it directly to an interface. This is not correct because a drop profile cannot be applied directly to an interface. A drop profile can only be referenced by a scheduler, which can be applied to an interface by using the scheduler-map statement under the [edit class-of-service interfaces] hierarchy level. For example: interfaces ge-0/0/0 { unit 0 { scheduler-map test-map; } }
NEW QUESTION # 43
Which two statements are correct about a sham link? (Choose two.)
- A. It creates a BGP multihop neighborship between two PE routers.
- B. The PEs exchange Type 1 OSPF LSAs instead of Type 3 OSPF LSAs for the L3VPN routes
- C. The PEs exchange Type 3 OSPF LSAs instead of Type 1 OSPF LSAs for the L3VPN routes.
- D. It creates an OSPF multihop neighborship between two PE routers.
Answer: B,D
Explanation:
A sham link is a logical link between two PE routers that belong to the same OSPF area but are connected through an L3VPN. A sham link makes the PE routers appear as if they are directly connected, and prevents OSPF from preferring an intra-area back door link over the VPN backbone. A sham link creates an OSPF multihop neighborship between the PE routers using TCP port 646. The PEs exchange Type 1 OSPF LSAs instead of Type 3 OSPF LSAs for the L3VPN routes, which allows OSPF to use the correct metric for route selection1.
NEW QUESTION # 44
Which two statements are correct about VPLS tunnels? (Choose two.)
- A. BGP-signaled VPLS tunnels require manual provisioning of sites.
- B. LDP-signaled VPLS tunnels only support control bit 0.
- C. BGP-signaled VPLS tunnels can use either RSVP or LDP between the PE routers.
- D. LDP-signaled VPLS tunnels use auto-discovery to provision sites
Answer: B,C
Explanation:
https://www.juniper.net/documentation/us/en/software/nce/feature-guide-virtual-private-lan-service/topics/task/v
https://www.juniper.net/documentation/us/en/software/junos/vpn-l2/topics/concept/vpns-configuring-vpls-routin
NEW QUESTION # 45
What is the correct order of packet flow through configurable components in the Junos OS CoS features?
- A. Multifield Classifier -> Behavior Aggregate Classifier -> Input Policer -> Forwarding Policy Options -> Fabric Scheduler -> Output Policer -> Rewrite Marker -> Scheduler/Shaper/RED
- B. Behavior Aggregate Classifier -> Input Policer -> Multifield Classifier -> Forwarding Policy Options -> Fabric Scheduler -> Output Policer -> Scheduler/Shaper/RED -> Rewrite Marker
- C. Behavior Aggregate Classifier -> Multifield Classifier -> Input Policer -> Forwarding Policy Options -> Fabric Scheduler -> Output Policer -> Scheduler/Shaper/RED -> Rewrite Marker
- D. Behavior Aggregate Classifier -> Multifield Classifier -> Input Policer -> Forwarding Policy Options -> Fabric Scheduler -> Scheduler/Shaper/RED -> Output Policer -> Rewrite Marker
Answer: C
Explanation:
https://www.juniper.net/documentation/us/en/software/junos/cos/topics/concept/packet-flow-cos-process-cos-config-guide.html
NEW QUESTION # 46
Which two statements about IS-IS are correct? (Choose two.)
- A. CSNPs contain only descriptions of LSPs.
- B. CSNPs are flooded periodically.
- C. PSNPs are flooded periodically.
- D. PSNPs contain only descriptions of LSPs.
Answer: B,D
Explanation:
LSPs contain information about the state and cost of links in the network, and are flooded periodically throughout the network. PSNPs are used to acknowledge receipt of LSPs and request retransmission of missing or corrupted LSPs. PSNPs contain only descriptions of LSPs, such as their sequence numbers and checksums. CSNPs contain a complete list of all link-state PDUs in the IS-IS database. CSNPs are sent periodically on all links, and the receiving systems use the information in the CSNP to update and synchronize their link-state PDU databases.
NEW QUESTION # 47
A packet is received on an interface configured with transmission scheduling. One of the configured queues In this scenario, which two actions will be taken by default on a Junos device? (Choose two.)
- A. The excess traffic will use bandwidth available from other queueses
- B. The exceeding queue will be considered to have positive bandwidth credit
- C. The exceeding queue will be considered to have negative bandwidth credit.
- D. The excess traffic will be discarded
Answer: C,D
Explanation:
https://www.juniper.net/documentation/us/en/software/junos/cos-security-devices/topics/concept/cos-transmissio
NEW QUESTION # 48
Which statement is correct about IS-IS when it performs the Dijkstra algorithm?
- A. Tuples with the lowest cost are moved from the tree database to the LSDB.
- B. The local router moves its own local tuples into the candidate database
- C. When a new neighbor ID in the tree database matches a router ID in the LSDB, the neighbor ID is moved to the candidate database
- D. The algorithm will stop processing once the tree database is empty.
Answer: B
Explanation:
IS-IS is a link-state routing protocol that uses the Dijkstra algorithm to compute the shortest paths between nodes in a network. The Dijkstra algorithm maintains three data structures: a tree database, a candidate database, and a link-state database (LSDB). The tree database contains the nodes that have been visited and their shortest distances from the source node. The candidate database contains the nodes that have not been visited yet and their tentative distances from the source node. The LSDB contains the topology information of the network, such as the links and their costs.
The Dijkstra algorithm works as follows:
The local router moves its own local tuples into the tree database. A tuple consists of a node ID, a distance, and a parent node ID. The local router's tuple has a distance of zero and no parent node.
The local router moves its neighbors' tuples into the candidate database. The neighbors' tuples have distances equal to the costs of the links to them and parent node IDs equal to the local router's node ID.
The local router selects the tuple with the lowest distance from the candidate database and moves it to the tree database. This tuple becomes the current node.
The local router updates the distances of the current node's neighbors in the candidate database by adding the current node's distance to the link costs. If a shorter distance is found, the parent node ID is also updated.
The algorithm repeats steps 3 and 4 until either the destination node is reached or the candidate database is empty.
NEW QUESTION # 49
You enabled a new router (R3) in your network but all destinations using IS-IS routes are not properly load balancing over this new router.
Referring to the exhibit, what is the problem?
- A. R1 is missing internal routes for R2.
- B. R3 does not have wide-metrics enabled.
- C. R2 is missing internal routes for R1.
- D. R1 does not have wide-metrics enabled.
Answer: B
NEW QUESTION # 50
You are using a Layer 3 VPN to connect two customer sites. The VPN routes for the customer networks appear as hidden in the bgp. 13vpn. o routing table on the PE routers.
What is causing this problem?
- A. There is not an established MPLS LSP between the two PE routers.
- B. Route targets are not configured.
- C. There is a routing loop in the service provider backbone.
- D. The routes use overlapping IP addresses.
Answer: A
Explanation:
For a Layer 3 VPN to function correctly, an MPLS Label Switched Path (LSP) must be established between the Provider Edge (PE) routers. The MPLS LSP is necessary for the transport of VPN traffic across the service provider's backbone network. If the MPLS LSP is not established, the PE routers cannot forward the VPN traffic properly, causing the routes to be hidden in the BGP routing table.
Here's a breakdown of why the other options are less likely:
A: The routes use overlapping IP addresses.
* Overlapping IP addresses might cause issues with route advertisement and selection, but they would not typically cause routes to be hidden in the bgp.l3vpn.0 table.
C: There is a routing loop in the service provider backbone.
* While routing loops are problematic, they would not specifically cause the routes to be hidden in the bgp.l3vpn.0 table. Routing loops would more likely result in dropped packets or increased latency.
D: Route targets are not configured.
* Incorrect or missing route target configuration would prevent routes from being imported into the correct VRF, but it would not usually result in the routes being hidden. Instead, they would simply not appear in the relevant VRF.
Thus, the absence of an established MPLS LSP is the most plausible cause for the routes being hidden.
NEW QUESTION # 51
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Tested Material Used To JN0-664: https://simplilearn.actual4labs.com/Juniper/JN0-664-actual-exam-dumps.html