[Sep 10, 2025] JN0-664 Exam Brain Dumps - Study Notes and Theory
Pass Juniper JN0-664 Test Practice Test Questions Exam Dumps
Juniper JN0-664 exam covers a wide range of topics related to Service Provider Routing and Switching. It includes areas such as OSPF, BGP, MPLS, Layer 2 and Layer 3 VPNs, multicast, and more. Candidates who take JN0-664 exam are expected to have a solid understanding of these topics and their practical applications.
The JN0-664 exam covers a wide range of topics, including OSPF, IS-IS, BGP, MPLS, Layer 3 VPNs, Layer 2 VPNs, Class of Service, and IP multicast. JN0-664 exam consists of 65 multiple-choice questions that need to be completed within 120 minutes. JN0-664 exam is computer-based, and the passing score is 65%. Candidates who pass the JN0-664 exam will be awarded the Juniper Networks Certified Professional Service Provider (JNCIP-SP) certification.
NEW QUESTION # 50
You are configuring a Layer 3 VPN between two sites. You are configuring the vrf-target target : 65100:100 statement in your routing instance.
In this scenario, which two statements describe the vrf-target configuration? (Choose two.)
- A. This value is used to add a target community to BGP routes advertised to the remote PE device.
- B. This value is used to identify BGP routes learned from the local CE device.
- C. This value is used to identify BGP routes learned from the remote PE device.
- D. This value is used to add a target community to BGP routes advertised to the local CE device.
Answer: A,C
Explanation:
The `vrf-target` statement in a Layer 3 VPN configuration is used to control the import and export of VPN routes by attaching a target community to the routes. This helps in defining which VPN routes should be imported into or exported from a particular VRF (Virtual Routing and Forwarding) instance.
1. **Understanding VRF Target**:
- The `vrf-target` statement specifies the extended community attributes (route targets) that are used to control the import and export of routes in a VRF.
- These attributes help in identifying which routes should be shared between different VRFs, particularly across different PE (Provider Edge) devices.
2. **Statements Analysis**:
- **A. This value is used to identify BGP routes learned from the local CE device.**
- Incorrect. The `vrf-target` attribute is not used to identify routes learned from the local CE device. It is used to manage routes between PE devices and within the provider's MPLS network.
- **B. This value is used to identify BGP routes learned from the remote PE device.**
- Correct. The `vrf-target` value helps in identifying which routes from remote PE devices should be imported into the local VRF. It essentially acts as a filter for importing BGP routes with matching target communities.
- **C. This value is used to add a target community to BGP routes advertised to the local CE device.**
- Incorrect. Routes advertised to the local CE device do not use the `vrf-target` attribute. Instead, these routes are typically managed within the local VRF routing table.
- **D. This value is used to add a target community to BGP routes advertised to the remote PE device.**
- Correct. When advertising routes from the local PE to remote PE devices, the `vrf-target` value is added to these routes. This target community ensures that the correct routes are shared across the VPN.
**Conclusion**:
The correct statements about the `vrf-target` configuration in a Layer 3 VPN scenario are:
**B. This value is used to identify BGP routes learned from the remote PE device.**
**D. This value is used to add a target community to BGP routes advertised to the remote PE device.**
**Reference**:
- Juniper Networks Documentation on VRF Target: [VRF Target Configuration](https://www.juniper.net/documentation/en_US/junos/topics/topic-map/layer-3-vpns.html)
- MPLS and VPN Architectures by Ivan Pepelnjak and Jim Guichard
NEW QUESTION # 51
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 -> Multifield Classifier -> Input Policer -> 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 -> Scheduler/Shaper/RED -> Output Policer -> Rewrite Marker
- D. Behavior Aggregate Classifier -> Input Policer -> Multifield Classifier -> Forwarding Policy Options -> Fabric Scheduler -> Output Policer -> Scheduler/Shaper/RED -> Rewrite Marker
Answer: D
Explanation:
Explanation
The correct order of packet flow through configurable components in the Junos OS CoS features is as follows:
* Behavior Aggregate Classifier: This component uses a single field in a packet header to classify traffic into different forwarding classes and loss priorities based on predefined or user-defined values.
* Input Policer: This component applies rate-limiting and marking actions to incoming traffic based on the forwarding class and loss priority assigned by the classifier.
* Multifield Classifier: This component uses multiple fields in a packet header to classify traffic into different forwarding classes and loss priorities based on user-defined values and filters.
* Forwarding Policy Options: This component applies actions such as load balancing, filtering, or routing to traffic based on the forwarding class and loss priority assigned by the classifier.
* Fabric Scheduler: This component schedules traffic across the switch fabric based on the forwarding class and loss priority assigned by the classifier.
* Output Policer: This component applies rate-limiting and marking actions to outgoing traffic based on the forwarding class and loss priority assigned by the classifier.
* Scheduler/Shaper/RED: This component schedules, shapes, and drops traffic at the egress interface based on the forwarding class and loss priority assigned by the classifier.
* Rewrite Marker: This component rewrites the code-point bits of packets leaving an interface based on the forwarding class and loss priority assigned by the classifier.
NEW QUESTION # 52 
Click the Exhibit button.
You have an OSPF environment. You have recently added a router called R4 that is directly connected to R1 and R2. You discover that R4 is only peering with R2.
Referring to the exhibit, how would you correct the peering?
- A. Change the MTU size on R1 and R2 to be 22 bytes higher than R4's MTU size.
- B. Adjust the Priority on R1 to be lower than the Priority on R4.
- C. Adjust the Hello Interval on R1 and R2 to match the Hello Interval on R4.
- D. Adjust the Dead Interval on R4 to match the Dead Interval on R1 and R2.
Answer: D
Explanation:
In OSPF, routers form adjacencies by exchanging Hello packets. These packets contain several parameters that must match between OSPF neighbors to establish a successful adjacency. Key among these parameters are the Hello Interval and the Dead Interval.
Let's analyze the exhibit and the question to determine the correct course of action to ensure that R4 peers with both R1 and R2.
1. **OSPF Hello and Dead Intervals**:
- **Hello Interval**: The time in seconds between Hello packets sent out by a router. Default is usually 10 seconds for broadcast and point-to-point networks.
- **Dead Interval**: The time in seconds that a router will wait to receive a Hello packet from a neighbor before declaring the neighbor down. Default is usually four times the Hello Interval (40 seconds).
2. **Analysis of the Exhibit**:
- **R1's Interface**: Shows a Dead Interval of 40 seconds.
- **R2's Interface**: Shows a Dead Interval of 40 seconds.
- **R4's Interface**: Shows a Dead Interval of 20 seconds.
From the exhibit, we can see that R4 has a Dead Interval of 20 seconds, while R1 and R2 have Dead Intervals of 40 seconds. This discrepancy prevents R4 from establishing an OSPF peering with R1.
3. **Option Analysis**:
- **A. Adjust the Priority on R1 to be lower than the Priority on R4**:
- Incorrect. The OSPF Priority is used for DR/BDR election on multi-access networks and does not impact peering issues.
- **B. Change the MTU size on R1 and R2 to be 22 bytes higher than R4's MTU size**:
- Incorrect. While MTU mismatches can prevent OSPF adjacencies, the exhibit does not indicate an MTU mismatch issue.
- **C. Adjust the Dead Interval on R4 to match the Dead Interval on R1 and R2**:
- Correct. Matching the Dead Interval on R4 to 40 seconds will ensure that all routers have consistent Hello and Dead Intervals, allowing OSPF adjacencies to form.
- **D. Adjust the Hello Interval on R1 and R2 to match the Hello Interval on R4**:
- While this would be a valid approach if the Hello Intervals were mismatched, the exhibit shows that the Hello Intervals are consistent (10 seconds) across all routers. Therefore, this adjustment is not necessary.
**Conclusion**:
To correct the OSPF peering issue, the Dead Interval on R4 should be adjusted to match the Dead Intervals on R1 and R2. The correct answer is:
**C. Adjust the Dead Interval on R4 to match the Dead Interval on R1 and R2.**
**References**:
- Juniper Networks Documentation on OSPF: [OSPF
Overview](https://www.juniper.net/documentation/en_US/junos/topics/concept/ospf-routing-overview.html)
- OSPF Configuration Guide: [Configuring
OSPF](https://www.juniper.net/documentation/en_US/junos/topics/task/configuration/ospf-configuring.html)
NEW QUESTION # 53
You are configuring schedulers to define the class-of-service properties of output queues. You want to control packet drops during periods of congestion.
In this scenario, which CoS configuration parameter would be used to accomplish this task?
- A. priority
- B. shaping rate
- C. buffer size
- D. drop profile
Answer: D
Explanation:
When configuring Class of Service (CoS) properties for output queues, we need to manage packet drops during periods of congestion. Juniper's CoS framework provides several tools to manage congestion, including drop profiles, buffer sizes, and scheduling mechanisms. Let's break down each option and identify the correct one.
Evaluating the Answer Choices
✅ D. drop profile (Correct Answer)
Why?
A drop profile defines when packets should be dropped based on the queue fill level.
Random Early Detection (RED) or Tail Drop can be used to manage congestion by discarding lower-priority packets first.
Drop profiles are configured under the scheduler to determine how aggressive packet dropping should be during congestion.
Example Juniper Configuration:
schedulers {
best-effort {
drop-profile low-drop;
}
}
drop-profiles {
low-drop {
fill-level 80 drop-probability 50;
}
}
fill-level 80 → When the queue reaches 80% full, packet drops begin.
drop-probability 50 → There is a 50% chance of dropping packets once the threshold is reached.
Official Juniper Documentation Reference:
Junos Class of Service Configuration Guide
"A drop profile determines how packets are discarded based on the queue fill level, allowing control over congestion behavior." Why the Other Options Are Incorrect?
❌ A. buffer size (Incorrect)
Why?
The buffer size determines how many packets the queue can store before congestion occurs.
A larger buffer can delay drops, but it does not actively control dropping behavior.
It affects latency rather than controlling packet drops.
❌ B. priority (Incorrect)
Why?
Priority controls which queue gets serviced first, not how drops are handled.
Higher priority queues are serviced before lower-priority queues, but this does not prevent congestion-related drops.
❌ C. shaping rate (Incorrect)
Why?
Shaping limits the maximum transmission rate of the queue.
While shaping helps reduce congestion, it does not control which packets get dropped during congestion.
Shaping is useful for traffic smoothing, but it does not actively drop packets based on queue fill levels.
Final answer: ✅ D. drop profile
Controls packet drops based on queue congestion.
Defines RED (Random Early Detection) or Tail Drop mechanisms.
Directly influences drop probability as the queue fills up.
Official Juniper Reference:
"Drop profiles are used to manage congestion by determining when and how aggressively packets are dropped based on queue fill level."
NEW QUESTION # 54
Exhibit
You are attempting to summarize routes from the 203.0.113.128/25 IP block on R8 to AS 64500. You implement the export policy shown in the exhibit and all routes from the routing table stop being advertised.
In this scenario, which two steps would you take to summarize the route in BGP? (Choose two.)
- A. Remove the from protocol bgp command from the export policy.
- B. Replace exact in the export policy with orlonger.
- C. Add the set protocols bgp family inet unicast add-path command to allow additional routes to the RIB tables. -
- D. Add the set routing-options static route 203.0.113.123/25 discard command.
Answer: A,D
NEW QUESTION # 55
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 -> Multifield Classifier -> Input Policer -> 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 -> Scheduler/Shaper/RED -> Output Policer -> Rewrite Marker
- D. Behavior Aggregate Classifier -> Input Policer -> Multifield Classifier -> Forwarding Policy Options -> Fabric Scheduler -> Output Policer -> Scheduler/Shaper/RED -> Rewrite Marker
Answer: D
Explanation:
The correct order of packet flow through configurable components in the Junos OS CoS features is as follows:
Behavior Aggregate Classifier: This component uses a single field in a packet header to classify traffic into different forwarding classes and loss priorities based on predefined or user-defined values.
Input Policer: This component applies rate-limiting and marking actions to incoming traffic based on the forwarding class and loss priority assigned by the classifier.
Multifield Classifier: This component uses multiple fields in a packet header to classify traffic into different forwarding classes and loss priorities based on user-defined values and filters.
Forwarding Policy Options: This component applies actions such as load balancing, filtering, or routing to traffic based on the forwarding class and loss priority assigned by the classifier.
Fabric Scheduler: This component schedules traffic across the switch fabric based on the forwarding class and loss priority assigned by the classifier.
Output Policer: This component applies rate-limiting and marking actions to outgoing traffic based on the forwarding class and loss priority assigned by the classifier.
Scheduler/Shaper/RED: This component schedules, shapes, and drops traffic at the egress interface based on the forwarding class and loss priority assigned by the classifier.
Rewrite Marker: This component rewrites the code-point bits of packets leaving an interface based on the forwarding class and loss priority assigned by the classifier.
NEW QUESTION # 56
Which statement is true regarding BGP FlowSpec?
- A. It uses a remote triggered black hole to protect a network from a denial-of-service attack.
- B. It verifies that the source IP of the incoming packet has a resolvable route in the routing table
- C. It is used to protect a network from denial-of-service attacks dynamically
- D. It uses dynamically created routing policies to protect a network from denial-of-service attacks
Answer: D
Explanation:
BGP FlowSpec is a feature that extends the Border Gateway Protocol (BGP) to enable routers to exchange traffic flow specifications, allowing for more precise control of network traffic. The BGP FlowSpec feature enables routers to advertise and receive information about specific flows in the network, such as those originating from a particular source or destined for a particular destination. Routers can then use this information to construct traffic filters that allow or deny packets of a certain type, rate limit flows, or perform other actions1. BGP FlowSpec can also help in filtering traffic and taking action against distributed denial of service (DDoS) attacks by dropping the DDoS traffic or diverting it to an analyzer2. BGP FlowSpec rules are internally converted to equivalent Cisco Common Classification Policy Language (C3PL) representing corresponding match and action parameters2. Therefore, BGP FlowSpec uses dynamically created routing policies to protect a network from denial-of-service attacks.
References: 1: https://www.networkingsignal.com/what-is-bgp-flowspec/ 2:
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-16/irg-xe-16-book/bgp-flowspe
NEW QUESTION # 57
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 instance type should be changed to I2vpn.
- 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 no-tunnel-services statement should be deleted on both PEs.
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 # 58
R2 is receiving the same route from R1 and R3. You must ensure that you can load balance traffic for that route.
Referring to the exhibit, which configuration change will allow load balancing?
- A. Configure the multipath parameter under the global BGP configuration.
- B. Configure the multipath multiple-as parameter under the global BGP configuration.
- C. Apply the prepend policy as an import policy under group R3.
- D. Apply the prepend policy as an import policy under group R1.
Answer: B
NEW QUESTION # 59
Exhibit
Which two statements are true about the OSPF adjacency displayed in the exhibit? (Choose two.)
- A. There is a mismatch in the dead interval parameter between routers R1 and R2.
- B. There is a mismatch in the hello interval parameter between routers R1 and R2
- C. There is a mismatch in the poll interval parameter between routers R1 and R2.
- D. There is a mismatch in the OSPF hold timer parameter between routers R1 and R2.
Answer: A,B
Explanation:
The hello interval is the time interval between two consecutive hello packets sent by an OSPF router on an interface. The dead interval is the time interval after which a neighbor is declared down if no hello packets are received from it. These parameters must match between two OSPF routers for them to form an adjacency. In the exhibit, router R1 has a hello interval of 10 seconds and a dead interval of 40 seconds, while router R2 has a hello interval of 30 seconds and a dead interval of 120 seconds. This causes a mismatch and prevents them from becoming neighbors23.
NEW QUESTION # 60
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: D
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 # 61
Click the Exhibit button.
Referring to the exhibit, which statement is correct?
- A. VPN routes are exported with only the target:65512:1 route target
- B. VPN routes are exported with the target:65512:1 and target:65512:2 route targets.
- C. VPN routes with the target:65512:1 and target:65512:2 route targets are imported.
- D. You cannot use the vrf-target and vrf-export statements in the same VRF.
Answer: B
Explanation:
The exhibit shows the configuration of a VRF (Virtual Routing and Forwarding) instance on a Juniper PE router. Let's break down the key components:
VRF Configuration (VPN-A)
The instance type is VRF, meaning this is an L3VPN (Layer 3 VPN).
The routing instance contains a static route (10.1.0.0/16 next-hop 10.1.0.1).
The interface ge-0/0/2.0 is assigned to the VRF.
Route Distinguisher (RD): 172.17.20.1:1
VRF-Export Policy: vpn-a-export
VRF-Target: target:65512:1 (This defines which routes will be imported into the VRF).
VRF Export Policy (vpn-a-export)
The vpn-a-export policy adds two BGP communities (route targets) to exported VPN routes:
community add vpn-a-target;
community add vpn-m-target;
accept;
The vpn-a-target community corresponds to target:65512:1.
The vpn-m-target community corresponds to target:65512:2.
Policy-Options (Community Definitions)
community vpn-a-target members target:65512:1;
community vpn-m-target members target:65512:2;
This confirms that routes exported from this VRF will have BOTH target:65512:1 and target:65512:2.
Evaluating the Answer Choices
✅ Option A: "VPN routes are exported with the target:65512:1 and target:65512:2 route targets." The vpn-a-export policy explicitly adds both vpn-a-target (65512:1) and vpn-m-target (65512:2) to exported routes.
This is correct. ✅
❌ Option B: "You cannot use the vrf-target and vrf-export statements in the same VRF." This is incorrect.
Juniper allows the use of both vrf-target and vrf-export in the same VRF:
vrf-target is used for importing routes.
vrf-export defines export policies (which can add additional route targets).
This is incorrect. ❌
❌ Option C: "VPN routes with the target:65512:1 and target:65512:2 route targets are imported." The vrf-target target:65512:1; statement only controls importing routes.
The import policy does not include target:65512:2, so routes tagged with target:65512:2 alone would not be imported into this VRF.
This is incorrect. ❌
❌ Option D: "VPN routes are exported with only the target:65512:1 route target." The export policy (vpn-a-export) clearly adds both 65512:1 and 65512:2.
This is incorrect. ❌
Final answer:
✅ A. VPN routes are exported with the target:65512:1 and target:65512:2 route targets.
Verification from Juniper Documentation
Juniper MPLS L3VPN Configuration Guide confirms that vrf-target is used for importing, while vrf-export can be used for exporting multiple route targets.
Juniper Routing Policy Documentation states that export policies can add multiple BGP communities (route targets).
RFC 4364 (BGP/MPLS IP VPNs) defines the use of route targets for VPN route control.
NEW QUESTION # 62
Which two statements are correct about reflecting inet-vpn unicast prefixes in BGP route reflection? (Choose two.)
- A. Clients add their originator ID when advertising routes to their route reflector
- B. A BGP peer does not require any configuration changes to become a route reflector client.
- C. Route reflectors do not change any existing BGP attributes by default when advertising routes.
- D. Route reflectors add their cluster ID to the AS path when readvertising client routes.
Answer: B,C
Explanation:
Explanation
Route reflection is a BGP feature that allows a router to reflect routes learned from one IBGP peer to another IBGP peer, without requiring a full-mesh IBGP topology. Route reflectors do not change any existing BGP attributes by default when advertising routes, unless explicitly configured to do so. A BGP peer does not require any configuration changes to become a route reflector client, only the route reflector needs to be configured with the client parameter under [edit protocols bgp group group-name neighbor neighbor-address] hierarchy level.
NEW QUESTION # 63
Exhibit
You are asked to exchange routes between R1 and R4 as shown in the exhibit. These two routers use the same AS number Which two steps will accomplish this task? (Choose two.)
- A. Configure the BGP group with the advertise-peer-as parameter on R2 and R3.
- B. Configure the BGP group with the as-override parameter on R2 and R3
- C. Configure the BGP group with the as-override parameter on R1 and R4
- D. Configure the BGP group with the advertise-peer-as parameter on R1 and R4.
Answer: A,B
Explanation:
https://www.juniper.net/documentation/us/en/software/junos/routing-policy/bgp/topics/example/bgp-advertise-peer-as.html
NEW QUESTION # 64
Which three mechanisms are used by Junos platforms to evaluate incoming traffic for CoS purposes? (Choose three )
- A. behavior aggregate classifiers
- B. traffic shapers
- C. rewrite rules
- D. multifield classifiers
- E. fixed classifiers
Answer: A,D,E
Explanation:
Explanation
Junos platforms use different mechanisms to evaluate incoming traffic for CoS purposes, such as:
* Behavior aggregate classifiers: These classifiers use a single field in a packet header to classify traffic into different forwarding classes and loss priorities based on predefined or user-defined values.
* Fixed classifiers: These classifiers use a fixed field in a packet header to classify traffic into different forwarding classes and loss priorities based on predefined values.
* Multifield classifiers: These classifiers use multiple fields in a packet header to classify traffic into different forwarding classes and loss priorities based on user-defined values and filters.
Rewrite rules and traffic shapers are not used to evaluate incoming traffic for CoS purposes, but rather to modify or shape outgoing traffic based on CoS policies.
NEW QUESTION # 65
Which origin code is preferred by BGP?
- A. Internal
- B. Incomplete
- C. Null
- D. External
Answer: A
Explanation:
Prefer the route with the lower origin code. Routes learned from an IGP have a lower origin code than those learned from an exterior gateway protocol (EGP), and both have lower origin codes than incomplete routes (routes whose origin is unknown). https://www.juniper.net/documentation/us/en/software/junos/vpn-l2/bgp/topics/concept/routing-protocols-address-representation.html
NEW QUESTION # 66
Refer to the exhibit.
Click the Exhibit button.
After adding Customer C to your Layer 3 VPN, you must ensure that PE2 is receiving VPN routes for all customers attached to PE1, as shown in the exhibit.
Which operational command displays this information?
- A. show route table bgp.l3vpn.0
- B. show route table customer-c.inet.0
- C. show route summary
- D. show route table inet.0
Answer: A
Explanation:
Understanding the Exhibit and the Problem Statement
The diagram shows a Layer 3 VPN (L3VPN) setup where multiple customers (Customer A, B, and C) are connected across a service provider network using PE (Provider Edge) routers.
PE1 and PE2 exchange VPN routes for all customers using BGP/MPLS Layer 3 VPN (L3VPN) routing.
The question asks how to verify if PE2 is receiving VPN routes for Customer C.
Evaluating the Answer Choices
✅ B. show route table bgp.l3vpn.0 (Correct Answer)
Why?
This command shows all VPN routes stored in the BGP Layer 3 VPN table (bgp.l3vpn.0).
Since PE routers exchange VPN routes using MP-BGP, this table contains the VPN-IPv4 or VPN-IPv6 routes for all customers.
If PE2 is receiving routes from PE1 for Customer C, they will appear in bgp.l3vpn.0.
❌ A. show route table inet.0 (Incorrect)
Why?
The inet.0 table contains global unicast routes for the service provider's network.
VPN routes do not appear here because they are stored in VRF-specific tables.
This command won't help verify VPN route exchange between PE1 and PE2.
❌ C. show route table customer-c.inet.0 (Incorrect)
Why?
The table customer-c.inet.0 represents the VRF routing table for Customer C on the local PE.
It only shows locally installed routes for Customer C but does not confirm if PE2 is receiving routes from PE1.
This command is useful to check local VPN routing but not BGP route propagation.
❌ D. show route summary (Incorrect)
Why?
This command only provides a summary of route counts per protocol (BGP, OSPF, etc.).
It does not display specific VPN routes.
It is useful for general troubleshooting but doesn't confirm VPN route receipt.
Final answer: ✅ show route table bgp.l3vpn.0 (Option B)
Official Juniper Documentation Reference
Junos MPLS VPNs Configuration Guide
Juniper Documentation
"The show route table bgp.l3vpn.0 command displays all VPN-IPv4 routes learned via MP-BGP for Layer 3 VPNs."
NEW QUESTION # 67
Which three statements about IS-IS in a multi-area network are correct? (Choose three.)
- A. External L2 PDUs are only flooded to the local area's L2 routers.
- B. Internal L1 PDUs are only flooded to the local area's L1 routers.
- C. External L2 PDUs are flooded to all L2 routers in other areas.
- D. Internal L1 PDUs are flooded to the local area's L2 routers.
- E. Internal L1 PDUs are flooded to all L1 routers in other areas.
Answer: B,C,D
Explanation:
Intermediate System to Intermediate System (IS-IS) is a link-state routing protocol designed to move information efficiently within a computer network, a group of physically connected computers or similar devices. It operates in two levels, Level 1 (L1) and Level 2 (L2), and supports hierarchical routing within a multi-area network.
Let's analyze each statement to determine its correctness in the context of IS-IS multi-area networks.
1. **Statement A: Internal L1 PDUs are flooded to the local area's L2 routers.**
- This statement is correct. L1 PDUs (Protocol Data Units) are flooded within the L1 area and also to the L2 routers that are present in the same area. These L2 routers act as the boundary routers that connect the local L1 area to other L1 areas via L2.
2. **Statement B: External L2 PDUs are flooded to all L2 routers in other areas.**
- This statement is correct. L2 PDUs are flooded throughout the entire L2 backbone, which includes all L2 routers in different areas. This ensures that inter-area routing information is shared across the network.
3. **Statement C: Internal L1 PDUs are flooded to all L1 routers in other areas.**
- This statement is incorrect. Internal L1 PDUs are only flooded within the local L1 area. They do not cross L1 area boundaries; inter-area communication is handled by L2 routers.
4. **Statement D: Internal L1 PDUs are only flooded to the local area's L1 routers.**
- This statement is correct. Internal L1 PDUs are indeed only flooded within their local L1 area, and do not go beyond it.
5. **Statement E: External L2 PDUs are only flooded to the local area's L2 routers.**
- This statement is incorrect. External L2 PDUs are flooded to all L2 routers throughout the IS-IS network, not just to those in the local area. This allows L2 routers to maintain a complete map of the network's topology.
**Conclusion**:
Given the analysis, the correct answers are:
**A. Internal L1 PDUs are flooded to the local area's L2 routers.**
**B. External L2 PDUs are flooded to all L2 routers in other areas.**
**D. Internal L1 PDUs are only flooded to the local area's L1 routers.**
**References**:
- Juniper Networks Documentation on IS-IS: [IS-IS Overview](https://www.juniper.net/documentation/en_US
/junos/topics/concept/is-is-routing-overview.html)
- RFC 1195, Use of OSI IS-IS for Routing in TCP/IP and Dual Environments: [RFC 1195](https://tools.ietf.
org/html/rfc1195) which details the operation of IS-IS in multi-area networks.
NEW QUESTION # 68
Which two statements are correct about reflecting inet-vpn unicast prefixes in BGP route reflection? (Choose two.)
- A. Clients add their originator ID when advertising routes to their route reflector
- B. A BGP peer does not require any configuration changes to become a route reflector client.
- C. Route reflectors do not change any existing BGP attributes by default when advertising routes.
- D. Route reflectors add their cluster ID to the AS path when readvertising client routes.
Answer: B,C
Explanation:
Explanation
Route reflection is a BGP feature that allows a router to reflect routes learned from one IBGP peer to another IBGP peer, without requiring a full-mesh IBGP topology. Route reflectors do not change any existing BGP attributes by default when advertising routes, unless explicitly configured to do so. A BGP peer does not require any configuration changes to become a route reflector client, only the route reflector needs to be configured with the client parameter under [edit protocols bgp group group-name neighbor neighbor-address] hierarchy level.
NEW QUESTION # 69
Which two statements about IS-IS are correct? (Choose two.)
- A. PSNPs are flooded periodically.
- B. CSNPs are flooded periodically.
- C. CSNPs contain only descriptions of LSPs.
- D. PSNPs contain only descriptions of LSPs.
Answer: B,D
Explanation:
Option A (Correct):
* Complete Sequence Number PDUs (CSNPs) are periodically flooded by the Designated Intermediate System (DIS) on multi-access networks (e.g., Ethernet).
* This ensures all routers on the segment synchronize their Link-State Databases (LSDBs).
NEW QUESTION # 70
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