JNCIP-ENT Practice Test 5 — 25 Questions

Question 1

Which TWO factors can cause an EVPN instance on a Junos device to fail in importing incoming Type-2 MAC/IP routes? (Choose two)

Accepted Answer

The EVPN routing instance is missing or has an incorrect instance-type configured.. Route import failures in EVPN are typically caused by mismatched Route Targets between the advertising and receiving PE, or missing/incorrect EVPN routing instance configurations.

Answer

Configuring an incorrect BGP router ID on the remote peer.

Answer

Enabling MAC limit suppression on access ports.

Answer

Incorrect loopback MTU settings on the physical underlay interfaces.

Question 2

Which TWO types of OSPF areas allow the generation of Type-7 LSAs? (Choose two)

Accepted Answer

Not-So-Stubby Area (NSSA). Option B (Not-So-Stubby Area, NSSA) is correct because an NSSA is defined as a stub area that can import external routes via an Autonomous System Boundary Router (ASBR), and those external routes are flooded within the area as Type-7 LSAs (NSSA External LSAs). Option D (NSSA Totally Stubby Area) is also correct because it is simply an NSSA variant that additionally blocks Type-3 and Type-4 summary LSAs from the backbone, but it still permits an ASBR and therefore still generates Type-7 LSAs for redistributed external routes. Option A (Standard OSPF Non-backbone Area) is incorrect because a normal non-backbone area uses Type-5 LSAs for external routes, not Type-7. Option C (Standard OSPF Backbone Area, Area 0) is incorrect because the backbone is a standard area that floods external routes as Type-5 LSAs and never uses Type-7. Option E (OSPF Stub Area) is incorrect because a stub area does not allow an ASBR or external route redistribution, so no Type-7 LSAs can be generated there.

Answer

Standard OSPF Non-backbone Area

Answer

Standard OSPF Backbone Area (Area 0)

Answer

OSPF Stub Area

Question 3

Which EVPN route type is responsible for advertising MAC addresses combined with IP addresses (MAC/IP Advertisement Route)?

Accepted Answer

Route Type 2. Route Type 2 is the MAC/IP Advertisement Route, which carries a MAC address and optionally an IP address, facilitating both L2 bridging and L3 host routing.

Answer

Route Type 3

Answer

Route Type 4

Answer

Route Type 1

Question 4

Which Junos configuration hierarchy is used to disable the generation of OSPF Type-7 to Type-5 LSA translation on an NSSA Area Border Router (ABR)?

Accepted Answer

set protocols ospf area nssa translator-role never. To prevent an NSSA ABR from translating Type-7 LSAs into Type-5 LSAs, you use the 'no-summaries' or 'nssa translator never' commands. Specifically, disabling translation is done via 'set protocols ospf area nssa translator-role never'.

Answer

set protocols ospf area <name> stub no-translate

Answer

set protocols ospf translate-type7 off

Answer

set protocols ospf area <name> nssa no-translation

Question 5

Which TWO actions can be triggered when a MAC address limit is exceeded on a Juniper switch interface configured with MAC limiting? (Choose two)

Accepted Answer

drop. Configurable actions on MAC limit violation include drop and log, or drop and shutdown (disable) the interface.

Answer

quarantine

Answer

reboot

Answer

isolate-vlan

Question 6

Which THREE mechanisms are utilized by Junos to protect OSPF routing operations and control plane resources? (Choose three)

Accepted Answer

OSPF cryptographic authentication (MD5 or keychain-based authentication). Control plane protection for OSPF includes Routing Engine firewall filters (lo0 filters), OSPF cryptographic authentication (MD5/SHA), and OSPF graceful restart helper mode / overload control.

Answer

Strict TCP handshake validation for OSPF hello packets

Answer

IPsec tunnel encapsulation mandatory for all intra-area OSPFv2 packets

Question 7

A Junos router is configured with BGP path selection, and multiple paths arrive with different MED values. Under what specific condition does Junos compare the MED values of paths from different autonomous systems during route selection?

Accepted Answer

Junos compares MEDs from different ASs only when the 'always-compare-med' statement is configured under protocols bgp.. By default, Junos (like standard BGP implementations) only compares MEDs from different ASs if the 'always-compare-med' configuration is explicitly enabled.

Answer

Junos compares MEDs from different ASs when the AS path lengths are completely identical.

Answer

Junos never compares MEDs from different ASs under any circumstance.

Answer

Junos compares MEDs from different ASs automatically if the routes share the same IGP metric.

Question 8

You need to adjust the OSPF cost on a specific interface to manipulate path selection. Which command sets the OSPF cost on an interface?

Accepted Answer

set protocols ospf area 0.0.0.0 interface xe-0/0/0.0 cost 50. OSPF interface cost is explicitly configured under the interface hierarchy within protocols ospf using the 'cost' statement.

Answer

set routing-options interface xe-0/0/0.0 ospf-cost 50

Answer

set interfaces xe-0/0/0.0 ospf-cost 50

Answer

set protocols ospf area 0.0.0.0 interface xe-0/0/0.0 metric 50

Question 9

Which TWO statements are true regarding traffic shapers versus policers in Junos? (Choose two)

Accepted Answer

Shapers are typically implemented on egress interfaces. Shapers buffer excess traffic to smooth out bursts, whereas policers drop or mark exceeding traffic immediately.

Answer

Policers are primarily configured on egress interfaces for shaping purposes

Answer

Policers buffer exceeding traffic in dedicated memory queues

Answer

Shapers operate without drop profiles or buffer allocation

Question 10

Which THREE types of LSAs are blocked from entering an OSPF Totally Stubby Area? (Choose three)

Accepted Answer

Type 4 ASBR Summary LSAs. Totally stubby areas block summary LSAs (Type 3), ASBR summary LSAs (Type 4), and AS external LSAs (Type 5). Router (Type 1) and Network (Type 2) LSAs are allowed within the area.

Answer

Type 1 Router LSAs

Answer

Type 2 Network LSAs

Question 11

Which specific EVPN route type is responsible for carrying IP prefix routes, often used for inter-subnet forwarding in an IP-VRF-to-EVPN integration scenario?

Accepted Answer

Route Type 5. EVPN Route Type 5 is the IP Prefix Route, which allows the advertisement of IP prefixes (host or subnet routes) independently of MAC addresses, facilitating integrated routing and bridging (IRB) and inter-subnet forwarding.

Answer

Route Type 3

Answer

Route Type 2

Answer

Route Type 1

Question 12

An ISP engineer is troubleshooting an interdomain multicast deployment. A receiver in AS 65001 wants to receive a stream sourced in AS 65002. The RP in AS 65001 has no (S,G) state for the source, and the RP in AS 65002 is not sending any Source-Active messages. Both RPs are configured as MSDP peers over a working TCP session. Which statement explains why the RP in AS 65001 lacks source information?

Accepted Answer

The RP in AS 65002 must receive a PIM Register from the source's first-hop router before it can originate Source-Active messages.. Interdomain multicast with MSDP depends on the source domain's RP learning about active sources. The first-hop router registers sources with its local RP using PIM Register messages. Only after the RP has (S,G) state does it originate Source-Active messages to its MSDP peers. If no Register reaches that RP, no SA messages are generated, and the peer RP in the receiving domain has nothing to install.

Answer

The RP in AS 65001 must be configured as a candidate RP for the source's group range to receive Source-Active messages.

Answer

The MSDP TCP session must be encrypted with IPsec before Source-Active messages are exchanged.

Answer

The receiver's last-hop router must send an MSDP Source-Active request to the remote RP before any messages are sent.

Question 13

You are analyzing BGP EVPN updates and observe an Extended Community attached to a Type-2 route containing a sequence number. What is the primary function of this MAC Mobility Extended Community?

Accepted Answer

It facilitates loop-free MAC movement tracking by incrementing sequence numbers when a host changes attachment PEs.. The MAC Mobility Extended Community carries a sequence number used to resolve MAC moves. If a host moves from one PE to another, the new PE advertises the MAC with an incremented sequence number, causing all other PEs to update their tables to point to the new location.

Answer

It signals the EVPN split-horizon label for BUM traffic.

Answer

It determines the Designated Forwarder for multi-homed Ethernet segments.

Answer

It defines the VXLAN Network Identifier (VNI) mapping for data-plane decapsulation.

Question 14

Which TWO statements are correct regarding the behavior of policers in Junos? (Choose two)

Accepted Answer

Policers can mark the loss priority of exceeding packets. Policers can drop traffic or mark loss priority, and they operate based on token bucket algorithms.

Answer

Policers buffer exceeding packets in temporal memory queues until transmission capacity opens

Answer

Policers are always applied to egress interfaces only

Answer

Policers guarantee a minimum bandwidth allocation for best-effort traffic

Question 15

Which TWO parameters can be configured within a Junos scheduler definition? (Choose two)

Accepted Answer

transmit-rate. Schedulers include parameters such as transmit-rate, buffer-size, priority, and drop-profile-map.

Answer

rewrite-rule

Answer

bandwidth-limit

Answer

policer-action

Question 16

When configuring OSPF sham-links in Junos to support MPLS VPN back-door links, which TWO characteristics apply? (Choose two)

Accepted Answer

Sham-links are configured as point-to-point links between PE router loopback addresses within the VPN routing instance.. Sham-links are treated as intra-area links between PE routers and require a separate /32 IP address configured under the loopback or routing instance, appearing as unnumbered or numbered point-to-point links.

Answer

Sham-links are advertised as Type-5 external LSAs across the network.

Answer

Sham-links require physical interfaces dedicated solely to the backdoor connection.

Answer

Sham-links are only supported in OSPFv3, not OSPFv2.

Question 17

When configuring EVPN multi-homing in all-active mode, which THREE key components or concepts must be properly established across the PE routers? (Choose three)

Accepted Answer

A Designated Forwarder (DF) election mechanism using Type-4 routes to determine who forwards BUM traffic.. EVPN all-active multi-homing requires a consistent Ethernet Segment Identifier (ESI) across participating PEs, an active Designated Forwarder election (governed by Type-4 routes), and split-horizon filtering to prevent traffic loops.

Answer

Enabling Spanning Tree Protocol root bridge on all leaf nodes.

Answer

Configuring OSPF as the underlay routing protocol for EVPN signaling.

Question 18

Which standard Junos forwarding class is reserved for control plane traffic such as routing protocols and management traffic?

Accepted Answer

network-control. In Junos, the network-control forwarding class is reserved for control plane traffic to ensure it receives priority handling.

Answer

expedited-forwarding

Answer

assured-forwarding

Answer

best-effort

Question 19

A Junos router connects to a Layer 2 switch that has multiple receivers on VLAN 200. The switch is not running PIM, and the router is the only multicast router on the segment. You want the router to send IGMP general queries on the VLAN 200 interface and track receiver group memberships. Which configuration is required?

Accepted Answer

Enable IGMP on the VLAN 200 interface with a version compatible with the receivers.. The router must run IGMP on the interface that faces the receivers to act as the querier and maintain group membership state. IGMP queries solicit reports, and the reports populate the membership database that drives PIM joins. PIM alone does not perform this signaling, and IGMP snooping is a switch-side optimization, so IGMP on the interface with a matching version is the required configuration.

Answer

Configure a static multicast route for 224.0.0.0/4 pointing out the VLAN 200 interface.

Answer

Enable PIM sparse-mode on the VLAN 200 interface and configure an RP.

Answer

Enable IGMP snooping on the router's VLAN 200 interface.

Question 20

Which RADIUS attribute is commonly used to assign a specific session timeout value to an 802.1X authenticated client on an EX Series switch?

Accepted Answer

Session-Timeout (Attribute 27). RADIUS Attribute 27 (Session-Timeout) specifies the maximum number of seconds of service to be provided to the user.

Answer

Idle-Timeout (Attribute 28)

Answer

Tunnel-Client-End-Id (Attribute 66)

Answer

Termination-Action (Attribute 29)