Juniper JN0-664 JNCIP-SP Exam Practice Test Instant Access

Question 1

Which three statements about IS-IS in a multi-area network are correct? (Choose three.)

AInternal L1 PDUs are flooded to the local area's L2 routers.

BExternal L2 PDUs are flooded to all L2 routers in other areas.

CInternal L1 PDUs are flooded to all L1 routers in other areas.

DInternal L1 PDUs are only flooded to the local area's L1 routers.

EExternal L2 PDUs are only flooded to the local area's L2 routers.

Answer : A, B, D

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.**

**Reference**:

- 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.

Question 2

Which origin code is preferred by BGP?

AInternal

BExternal

CIncomplete

DNull

Answer : A

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

Question 3

Exhibit

Referring to the exhibit, PE-1 and PE-2 are getting route updates for VPN-B when neither of them service that VPN

Which two actions would optimize this process? (Choose two.)

AConfigure the resolution rib bgp.l3vpn.0 resolution-ribs inet.0 statement on the PEs.

BConfigure the family route-target statement on the RR.

CConfigure the resolution rib bgp.l3vpn.0 resolution-ribs inet.0 statement on the RR.

DConfigure the family route-target statement on the PEs.

Answer : B, C

BGP route target filtering can be configured on PE devices or on route reflectors (RRs). Configuring BGP route target filtering on RRs is more efficient and scalable, as it reduces the number of BGP sessions and updates between PE devices. To configure BGP route target filtering on RRs, the following steps are required:

Configure the family route-target statement under the BGP group or neighbor configuration on the RRs. This enables the exchange of the route-target address family between the RRs and their clients (PE devices). Configure the resolution rib bgp.l3vpn.0 resolution-ribs inet.0 statement under the routing-options configuration on the RRs. This enables the RRs to resolve next hops for VPN routes using the inet.0 routing table.

Question 4

Exhibit

Referring to the exhibit, what do the brackets [ ] in the AS path identify?

AThey identify the local AS number associated with the AS path if configured on the router, or if AS path prepending is configured

BThey identify an AS set, which are groups of AS numbers in which the order does not matter

CThey identify that the autonomous system number is incomplete and awaiting more information from the BGP protocol.

DThey identify that a BGP confederation is being used to ensure that there are no routing loops.

Answer : A

https://www.juniper.net/documentation/us/en/software/junos/cli-reference/topics/ref/command/show-route-advertising-protocol.html

Question 5

Click the Exhibit button.

Referring to the exhibit, which statement is correct?

AVPN routes are exported with the target:65512:1 and target:65512:2 route targets.

BYou cannot use the vrf-target and vrf-export statements in the same VRF.

CVPN routes with the target:65512:1 and target:65512:2 route targets are imported.

DVPN routes are exported with only the target:65512:1 route target

Answer : A

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.

Question 6

When using OSPFv3 for an IPv4 environment, which statement is correct?

AOSPFv3 only supports IPv4.

BOSPFv3 supports both IPv6 and IPv4, but not in the same routing instance.

COSPFv3 is not backward compatible with IPv4

DOSPFv3 supports IPv4 only on interfaces with family inet6 defined

Answer : D

Question 7

Which two statements are correct about VPLS tunnels? (Choose two.)

ALDP-signaled VPLS tunnels only support control bit 0.

BLDP-signaled VPLS tunnels use auto-discovery to provision sites

CBGP-signaled VPLS tunnels can use either RSVP or LDP between the PE routers.

DBGP-signaled VPLS tunnels require manual provisioning of sites.

Answer : A, C

https://www.juniper.net/documentation/us/en/software/nce/feature-guide-virtual-private-lan-service/topics/task/vpls-ldp-signaling-solutions.html

https://www.juniper.net/documentation/us/en/software/junos/vpn-l2/topics/concept/vpns-configuring-vpls-routing-instances.html#id-11510150__id-11568648

Juniper Service Provider Routing and Switching, Professional Exam JN0-664 JNCIP-SP Exam Practice Test