Juniper Networks Enterprise Routing and Switching, Professional (JNCIP-ENT, JN0-650) (JNCIP-ENT) JNCIP-ENT Questions 151–225 | Page 3/5

151

Multi-Selecthard

Which TWO actions can you take in Junos OS to optimize OSPF convergence times in a large enterprise network? (Choose two)

Select 2 answers

A.Configure faster Hello and Dead intervals on transit interfaces.

B.Tune the OSPF SPF delays using the 'set protocols ospf spf-options' hierarchy.

C.Disable link-state acknowledgement pacing globally.

D.Convert all backbone areas into completely stubby areas.

E.Increase the SPF hold-down timer to allow network stabilization before running computations.

AnswersA, B

Lowering hello and dead timers allows routers to detect link failures more rapidly.

Why this answer

OSPF convergence can be accelerated by tuning SPF schedule delays (spf-options) and adjusting interface-specific hello and dead intervals.

Full explanation →

152

MCQhard

You need to prevent an OSPF interface from participating in Designated Router (DR) election, forcing it to always act as a DROTHER, even if it has the highest priority. How is this achieved in Junos?

A.set protocols ospf area 0.0.0.0 interface xe-0/0/0.0 no-dr-election

B.set protocols ospf area 0.0.0.0 interface xe-0/0/0.0 priority 0

C.set protocols ospf area 0.0.0.0 interface xe-0/0/0.0 disable-dr

D.set protocols ospf area 0.0.0.0 interface xe-0/0/0.0 drother-only

AnswerA, B

Wait, 'no-dr-election' is not a valid Junos command; priority 0 is the correct method. Let's make sure the option text reflects correct evaluation. Actually, setting priority 0 is the correct method.

Why this answer

Setting the OSPF interface priority to 0 prevents the router from participating in DR/BDR elections and forces it to become a DROTHER.

Full explanation →

153

MCQeasy

An operator configures a BGP routing policy to modify the Local Preference attribute. Under which BGP neighbor relationship type can Local Preference be advertised and evaluated?

A.BGP confederation member AS boundaries only

B.Both EBGP and IBGP peers equally

C.External BGP (EBGP) peers only

D.Internal BGP (IBGP) peers only

AnswerD

Local Preference is strictly an IBGP attribute used for routing within an autonomous system.

Why this answer

Local Preference is an IBGP attribute and is exchanged only between internal BGP peers within the same autonomous system.

Full explanation →

154

Multi-Selectmedium

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

Select 2 answers

A.drop

B.quarantine

C.shutdown

D.reboot

E.isolate-vlan

AnswersA, C

Drops frames from unauthorized source MAC addresses.

Why this answer

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

Full explanation →

155

Multi-Selecthard

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

Select 3 answers

A.Type 1 Router LSAs

B.Type 2 Network LSAs

C.Type 4 ASBR Summary LSAs

D.Type 3 Summary LSAs

E.Type 5 AS External LSAs

AnswersC, D, E

Type 4 LSAs are blocked in totally stubby areas.

Why this answer

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.

Full explanation →

156

MCQeasy

What is the primary function of a behavior aggregate (BA) classifier in Junos CoS?

A.It classifies packets based exclusively on header CoS bits such as DSCP or EXP

B.It drops packets exceeding a predefined bandwidth rate

C.It rewrites VLAN tags on egress interfaces

D.It classifies packets based on Layer 4 port numbers and source IP addresses

AnswerA

BA classifiers use header bits to assign forwarding classes.

Why this answer

A Behavior Aggregate (BA) classifier classifies packets based solely on the CoS bits in the packet header (such as DSCP, EXP, or IEEE 802.1p).

Full explanation →

157

Multi-Selecthard

An administrator is designing a high-availability PIM sparse-mode network. Which THREE mechanisms are used to provide redundancy for Rendezvous Points (RPs)? (Choose three)

Select 3 answers

A.Anycast RP with MSDP peering between multiple RPs

B.IGMP snooping querier election redundancy across core switches

C.Static RP configuration with multiple backup RP IP addresses configured on every router

D.MBGP multipath routing for RPF path selection

E.Bootstrap Router (BSR) with multiple Candidate-RPs

AnswersA, D, E

Anycast RP combined with MSDP synchronizes source registrations across redundant RPs.

Why this answer

RP redundancy is typically achieved using static Anycast RP with MSDP, Bootstrap Router (BSR) dynamic discovery with multiple Candidate RPs, or Auto-RP (vendor-specific).

Full explanation →

158

MCQmedium

An engineer wants to configure a Junos router to act as a Bootstrap Router (BSR) for PIM sparse-mode. Which configuration hierarchy is used to enable the BSR function?

A.[edit protocols msdp bsr]

B.[edit protocols pim bsr]

C.[edit routing-options bsr]

D.[edit protocols pim candidate-rp]

AnswerB

Configuring the BSR candidate parameters and local interface address is done under protocols pim bsr.

Why this answer

BSR functionality on Junos is configured under protocols pim bsr.

Full explanation →

159

Multi-Selectmedium

Which TWO statements correctly describe the role of the Designated Router (DR) on a multi-access network running PIM sparse-mode? (Choose two)

Select 2 answers

A.The DR elects the IGMP querier for the VLAN segment.

B.The DR maintains the MSDP Source-Active cache for the entire AS.

C.The DR sends PIM join and prune messages towards the RP on behalf of local receivers when necessary.

D.The DR encapsulates multicast data packets from sources into PIM register messages sent to the RP.

E.The DR floods all multicast traffic across the multi-access segment by default.

AnswersC, D

The receiver-side DR acts on behalf of local hosts to join shared or source trees.

Why this answer

The PIM DR is responsible for sending register messages to the RP on behalf of sources and sending join/prune messages on behalf of receivers on a shared LAN segment.

Full explanation →

160

Multi-Selectmedium

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

Select 2 answers

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

B.Policers can mark the loss priority of exceeding packets

C.Policers are always applied to egress interfaces only

D.Policers guarantee a minimum bandwidth allocation for best-effort traffic

E.Policers use a token bucket algorithm to measure traffic rates

AnswersB, E

Exceeding traffic can have its loss priority remarked rather than being dropped.

Why this answer

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

Full explanation →

161

Multi-Selectmedium

An engineer is deploying VSTP on a Juniper EX Series network. Which THREE characteristics or limitations of VSTP should be considered during the design phase? (Choose three)

Select 3 answers

A.VSTP configuration requires enabling vstp under protocols and can be applied selectively per VLAN or globally.

B.VSTP allows interoperability with Cisco switches running PVST+ or Rapid-PVST+.

C.VSTP requires all switches in the topology to belong to the exact same named MST region.

D.VSTP automatically aggregates all VLAN spanning trees into a single BPDU transmission to save bandwidth.

E.VSTP creates a separate spanning tree instance for every defined VLAN, which can increase Routing Engine CPU load in very large VLAN environments.

AnswersA, B, E

VSTP can be enabled globally or enabled/disabled on a per-VLAN basis within the Junos configuration hierarchy.

Why this answer

VSTP operates per-VLAN, maintains full compatibility with Cisco PVST+, and scales linearly with the number of VLANs, which can consume significant CPU resources if not properly sized.

Full explanation →

162

Multi-Selectmedium

When deploying IP phones that utilize a voice VLAN on EX Series access ports, which THREE characteristics or configurations typically apply to this design? (Choose three.)

Select 3 answers

A.The switch port must be configured as a pure Layer 3 routed interface.

B.Untagged traffic generated by an attached PC passes through the phone into the native VLAN of the switch port.

C.The switch port is configured as an access port supporting both a data VLAN (native) and a voice VLAN.

D.The IP phone tags its own voice traffic with the designated voice VLAN ID.

E.The IP phone must be configured to run BGP to exchange voice routes with the switch.

AnswersB, C, D

PC traffic remains untagged through the phone and maps to the switch port's native VLAN.

Why this answer

Voice VLAN deployments involve access ports with native data VLANs, tagged voice traffic, and proper LLDP-MED support.

Full explanation →

163

Multi-Selecthard

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

Select 2 answers

A.Sham-links are configured as point-to-point links between PE router loopback addresses within the VPN routing instance.

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

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

D.Sham-links prevent OSPF inter-area routing from preferring sub-optimal backdoor paths over the MPLS backbone.

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

AnswersA, D

Sham-links use /32 source and destination addresses inside the VPN routing instance.

Why this answer

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.

Full explanation →

164

MCQmedium

You want to map three loss priorities (low, medium-low, high) to different drop profiles within a specific forwarding class. Which statement should you use inside the scheduler configuration?

A.classifier-map

B.drop-profile-map

C.loss-priority-mapping

D.queue-drop-profile

AnswerB

drop-profile-map links loss priorities to drop profiles.

Why this answer

In Junos scheduler configurations, drop-profile-map associates a loss priority and forwarding class with a specific drop profile.

Full explanation →

165

MCQeasy

An enterprise network administrator needs to configure 802.1X authentication on EX Series switches. Which statement is correct regarding the default behavior of the supplicant timeout timer?

A.It dictates how long the switch waits before failing over to MAC RADIUS authentication.

B.It determines how long an authenticated client can remain idle before being disconnected.

C.It defines the duration the switch waits for an EAP-Request/Identity frame response before retransmitting.

D.It specifies the interval before the switch drops the entire RADIUS authentication session.

AnswerC

Correct. supp-timeout dictates the wait time for the initial identity response.

Why this answer

The supp-timeout timer specifies the time the switch waits for a response to an EAP-Request/Identity frame from the supplicant before retransmitting.

Full explanation →

166

Multi-Selectmedium

Which TWO statements describe the behavior of VSTP (VLAN Spanning Tree Protocol) on Juniper EX Series switches? (Choose two)

Select 2 answers

A.VSTP can interoperate with Cisco's PVST+ protocol.

B.VSTP is incompatible with RSTP fallback modes.

C.VSTP automatically disables all trunk ports if BPDU guard is triggered globally.

D.VSTP runs a separate Spanning Tree instance for each configured VLAN.

E.VSTP requires all VLANs to be mapped into a single master MSTI region.

AnswersA, D

VSTP is designed to interoperate with PVST/PVST+ using standard Cisco-compatible PVST BPDUs.

Why this answer

VSTP runs an independent spanning tree instance per VLAN and interoperates with PVST+.

Full explanation →

167

MCQhard

During multicast troubleshooting, an engineer notices that a router is not accepting MSDP Source-Active messages from a specific peer. Where should an export policy be applied to control which SA messages are sent or accepted via MSDP?

A.set protocols msdp peer <address> import <policy-name>

B.set routing-options msdp-policy <policy-name>

C.set protocols pim msdp-import <policy-name>

D.set protocols bgp group msdp export <policy-name>

AnswerA

Applying an import policy under the specific MSDP peer controls which incoming SA messages are accepted.

Why this answer

MSDP policies in Junos are applied directly under the specific MSDP peer configuration or globally under protocols msdp export/import.

Full explanation →

168

MCQeasy

Which configuration stanza is used to define custom forwarding classes in Junos?

A.[edit class-of-service drop-profiles]

B.[edit class-of-service classifiers]

C.[edit class-of-service forwarding-classes]

D.[edit class-of-service schedulers]

AnswerC

Forwarding classes are created under this hierarchy.

Why this answer

Custom forwarding classes are defined under the [edit class-of-service forwarding-classes] hierarchy.

Full explanation →

169

Multi-Selecthard

When configuring advanced Layer 2 tunneling (Q-in-Q) on Juniper EX Series switches, which THREE statements are correct regarding VLAN stacking behavior and limitations? (Choose three)

Select 3 answers

A.Layer 2 Protocol Tunneling (L2PT) is automatically enabled for all protocols without additional configuration when QinQ is active.

B.MTU sizes across the core must be adjusted to account for the extra 4 bytes of the added outer VLAN tag.

C.Incoming customer frames have an outer VLAN tag pushed onto them at the provider edge ingress port.

D.The inner customer VLAN tags remain entirely untouched and transparent as the frames traverse the provider core.

E.QinQ tunneling requires standard access mode encapsulation on all core-facing uplink ports.

AnswersB, C, D

Because stacked tags add overhead (an extra 4 bytes per tag), core link MTU must be increased to prevent frame fragmentation or drops.

Why this answer

QinQ on Juniper EX switches involves specific encapsulation requirements like flexible-ethernet-services, stacking VLAN tags on ingress and popping on egress, and preserving inner customer VLAN tags transparently.

Full explanation →

170

MCQhard

An administrator configures MSDP peering between two routers. After configuration, the MSDP session remains in the 'Connect' or 'Active' state and never transitions to 'Established'. Which underlying protocol dependency must be verified and operational for MSDP sessions to establish?

A.TCP connectivity on port 639 between the MSDP peers

B.MBGP unicast routing tables synchronized

C.PIM dense-mode adjacency between the peers

D.IGMPv3 snooping enabled on intermediate switches

AnswerA

MSDP runs over TCP using port 639; if TCP fails, the session cannot reach the Established state.

Why this answer

MSDP relies directly on TCP (TCP port 639) to establish peer connections. If TCP connectivity fails, the MSDP state will not reach Established.

Full explanation →

171

Multi-Selectmedium

Which TWO actions can be performed by an OSPF routing policy export filter when redistributing routes into OSPF? (Choose two)

Select 2 answers

A.Change the OSPF hello timer interval via routing policy.

B.Modify the OSPF route metric using the metric action.

C.Set the external metric type to Type-1 or Type-2.

D.Alter the OSPF router ID of neighboring routers.

E.Change the OSPF area ID of external routes dynamically.

AnswersB, C

Export policies can assign a specific metric to redistributed routes.

Why this answer

Routing policies when exporting into OSPF can set metric types (Type 1 or Type 2) and modify route metrics. They cannot directly change area ID during redistribution without area design changes.

Full explanation →

172

MCQmedium

You are troubleshooting a switching loop issue in an enterprise core utilizing MSTP. You run 'show mstp interface' and notice that a specific port is stuck in the discarding state for MSTI 1. Which command should you run to verify if root guard has been triggered on this port?

A.show spanning-tree inconsistent-ports

B.show bridge root-guard status

C.show mstp interface detail

D.show ethernet-switching security-guard

AnswerC

In Junos, 'show mstp interface detail' displays comprehensive port state information including root guard status and inconsistent port flags.

Why this answer

The command 'show mstp interface detail' provides detailed port-level status including whether root guard has tripped and placed the port into a inconsistent/discarding state.

Full explanation →

173

MCQeasy

An administrator needs to enable LLDP globally on an EX Series switch running Junos OS to support IP phones. Which command accomplishes this task?

A.set system lldp enable

B.set lldp global-enable

C.set ethernet-switching-options lldp

D.set protocols lldp

AnswerB, D

This option is incorrect; lldp is configured directly under protocols.

Why this answer

LLDP is enabled globally under the protocols hierarchy in Junos OS.

Full explanation →

174

MCQeasy

Which IPv4 multicast address range is designated for Source-Specific Multicast (SSM) operations according to IANA standards?

A.224.0.1.0/24

B.224.0.0.0/24

C.239.0.0.0/8

D.232.0.0.0/8

AnswerD

The 232.0.0.0/8 address block is specifically allocated for Source-Specific Multicast.

Why this answer

The range 232.0.0.0/8 is reserved for Source-Specific Multicast (SSM) by IANA.

Full explanation →

175

MCQmedium

An enterprise network architect is designing an EVPN-VXLAN fabric and wants to ensure that MAC address churn (frequent moving of a MAC between ports) does not destabilize the control plane. Which feature should be enabled in the EVPN instance?

A.MAC limit and MAC mobility sequence numbering

B.Spanning Tree BPDU protection

C.Fast-reroute backup paths

D.BGP route flap damping

AnswerA

MAC mobility uses sequence numbers to track legitimate moves and provides detection to suppress churn.

Why this answer

MAC mobility features, including MAC move detection and sticky MAC or suppression mechanisms, protect the EVPN control plane from frequent MAC moves by incrementing sequence numbers and applying penalties if movement thresholds are exceeded.

Full explanation →

176

MCQmedium

An administrator wants to configure MSTP on Juniper switches and needs to assign VLANs 10 through 50 to MST Instance 2. Which configuration command hierarchy is correct in Junos?

A.set protocols mstp configuration-name CORP instance-name msti2 vlan 10-50

B.set protocols spanning-tree mst instance 2 vlan-members 10-50

C.set protocols mstp configuration-name CORP msti 2 vlan 10-50

D.set protocols mstp region-name CORP revision 1 instance msti2 vlan [ 10-50 ]

AnswerC

The correct Junos syntax is 'set protocols mstp configuration-name <name> msti <id> vlan <vlan-list>'.

Why this answer

In Junos, MST configuration parameters such as instance mappings, revision numbers, and names are defined under the 'protocols mstp configuration-name' hierarchy.

Full explanation →

177

Multi-Selecteasy

Which TWO statements describe characteristics of BGP route reflectors? (Choose two)

Select 2 answers

A.They rewrite the AS path length attribute for all reflected client routes.

B.They replace the underlying IGP entirely for packet forwarding.

C.They operate exclusively at Layer 2 switching boundaries.

D.They eliminate the requirement for a full-mesh IBGP topology within an autonomous system.

E.They require all internal non-client routers to maintain a full mesh with each other.

AnswersD, E

Route reflectors reduce IBGP sessions from n(n-1)/2 to a hub-and-spoke design.

Why this answer

Route reflectors reduce IBGP mesh requirements and reflect routes according to strict client/non-client rules.

Full explanation →

178

Multi-Selectmedium

Which TWO statements are correct regarding captive portal redirection behavior on EX Series switches? (Choose two)

Select 2 answers

A.Clients can be granted pre-authentication access to specific IP addresses using a walled garden or bypass list.

B.Captive portal redirection requires the client to run a proprietary Juniper client software agent.

C.HTTPS traffic is automatically decrypted and redirected without client browser certificate errors.

D.Unauthenticated HTTP traffic is intercepted and redirected to the captive portal login URL.

E.Redirection is achieved by modifying the client's local operating system registry settings via DHCP.

AnswersA, D

Correct. Bypass lists permit pre-auth traffic.

Why this answer

Captive portal intercepts HTTP traffic to redirect unauthenticated clients and supports walled garden bypass for specific destinations.

Full explanation →

179

Multi-Selecteasy

Which TWO attributes are considered transitive BGP path attributes? (Choose two)

Select 2 answers

A.MED (Multi-Exit Discriminator)

B.ORIGINATOR_ID

C.LOCAL_PREF

D.COMMUNITY

E.AS_PATH

AnswersD, E

COMMUNITY is an optional transitive attribute.

Why this answer

AS_PATH and COMMUNITY are standard well-known transitive and optional transitive attributes respectively, whereas LOCAL_PREF is well-known discretionary (non-transitive across AS).

Full explanation →

180

MCQhard

During a maintenance window, an administrator needs to manually force a Designated Forwarder (DF) role change on a multi-homed Ethernet segment for an EVPN instance. Which parameter must be adjusted to influence the DF election algorithm in Junos OS?

A.BGP AS path prepending

B.Route Distinguisher value

C.Router ID of the BGP speaker

D.Ethernet segment preference value

AnswerD

Configuring a higher or lower segment preference value under the ESI configuration explicitly influences the DF election.

Why this answer

Junos OS allows influencing the DF election by adjusting the interface preference or local preference values associated with the Ethernet Segment, altering how the DF election algorithm selects the forwarder.

Full explanation →

181

Multi-Selecthard

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

Select 3 answers

A.OSPF cryptographic authentication (MD5 or keychain-based authentication)

B.Routing Engine firewall filters protecting the lo0 interface against OSPF spoofing/flooding

C.Strict TCP handshake validation for OSPF hello packets

D.IPsec tunnel encapsulation mandatory for all intra-area OSPFv2 packets

E.OSPF overload / stub router advertising during high CPU or startup

AnswersA, B, E

Cryptographic authentication prevents unauthorized routers from forming adjacencies.

Why this answer

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.

Full explanation →

182

MCQhard

An enterprise design uses PIM sparse-mode with a BSR. An engineer notices that the router has successfully elected a BSR, but no Candidate-RP messages are being processed. Which operational command should the engineer use to verify the BSR candidate information and elected BSR address on the router?

A.show igmp bsr

B.show pim bsr statistics

C.show msdp bsr-state

D.show multicast bsr

AnswerB

This command displays bootstrap messages received, elected BSR address, and candidate RP information.

Why this answer

The 'show pim bsr local' or 'show pim bsr' commands display information regarding the BSR state, elected BSR, and received bootstrap messages.

Full explanation →

183

MCQhard

An enterprise network engineer is designing a redundant Layer 2 topology with MSTP across Juniper EX switches. Two switches have identical bridge priorities and MAC addresses that result in a tie for regional root. How does MSTP deterministically break the tie to select the regional root bridge?

A.The switch with the highest interface count operational status wins.

B.The switch with the numerically lowest MAC address is selected as the root bridge.

C.The switch with the higher serial number stored in EEPROM is chosen.

D.MSTP triggers a randomized tie-breaker algorithm using the system uptime.

AnswerB

When bridge priorities are tied, the switch with the lowest base MAC address wins the election.

Why this answer

Spanning tree tie-breaking checks the bridge priority first, and if tied, compares the lowest MAC address of the switches.

Full explanation →

184

MCQeasy

You are configuring VSTP (VLAN Spanning Tree Protocol) on Juniper EX switches to interoperate with legacy third-party switches running PVST+. Which operational command allows you to verify the VSTP bridge identifier and root bridge status per VLAN?

A.show ethernet-switching vstp

B.show spanning-tree vlan detail

C.show vstp vlan

D.show bridge vstp-status

AnswerC

show vstp vlan provides per-VLAN spanning tree operational status.

Why this answer

The command 'show vstp vlan' displays the VSTP state, root bridge, and port roles for each VLAN.

Full explanation →

185

Multi-Selecthard

When designing advanced enterprise campus VLAN architectures with Juniper EX Series switches, which TWO considerations are critical for large-scale Layer 2 domains? (Choose two)

Select 2 answers

A.Configuring bridge assurance on all point-to-point links running MSTP to protect against unidirectional link failures.

B.Keeping failure domains small by limiting the physical span of a single VLAN or transitioning to routed access / EVPN-VXLAN architectures.

C.Disabling BPDU protection on core inter-switch links to allow unexpected root bridges to take over seamlessly.

D.Enabling spanning tree globally across all VLANs without instance mapping to ensure all switches share a single root bridge.

E.Setting the forward delay timer to 4 seconds across all switches to accelerate MSTP topology convergence.

AnswersA, B

Bridge assurance ensures that switches actively send BPDUs on all point-to-point operational ports, preventing loops caused by unidirectional link failures.

Why this answer

In large-scale Layer 2 networks, keeping broadcast domains small and controlling failure domains via multi-chassis link aggregation (MC-LAG or EVPN-VXLAN) and limiting spanning tree blast radius are essential design principles.

Full explanation →

186

MCQeasy

Which statement accurately describes the function of the 'server-timeout' setting within a Juniper access profile?

A.It determines the maximum duration a client session can remain active before forced re-authentication.

B.It defines how long the switch waits for a reply from the RADIUS server before failing over to the next server.

C.It dictates the interval at which the switch sends RADIUS accounting interim updates.

D.It specifies the idle timeout period for disconnected supplicants.

AnswerB

Correct. server-timeout controls the retry timer for RADIUS requests.

Why this answer

The server-timeout setting determines how long the switch waits for a response from a RADIUS server before trying the next server in the server group.

Full explanation →

187

MCQeasy

An administrator needs to configure PoE power management on an EX3400 switch to prioritize port ge-0/0/0 for a critical emergency IP phone. Which statement correctly describes the default PoE priority behavior on Junos EX switches if no explicit priority is configured?

A.All ports default to high priority and allocate power on a first-come, first-served basis.

B.PoE is disabled by default until an explicit priority is assigned to the interface.

C.Critical ports must be placed in a dedicated PoE policer to prevent disconnection.

D.All ports default to low priority, and power allocation is determined by port index order when budgets are constrained.

AnswerD

Junos assigns low priority to all interfaces by default.

Why this answer

By default, all ports on EX switches are assigned a low priority for PoE allocation. If the power budget is exceeded, ports are shut down based on priority and then port index.

Full explanation →

188

MCQeasy

Which command verifies the OSPF neighbor states and adjacency progress on a Junos device?

A.show ospf neighbor

B.show route table ospf.0 neighbor

C.show protocols ospf neighbors

D.show ospf adjacency

AnswerA

This is the correct operational command to check OSPF neighbors.

Why this answer

The 'show ospf neighbor' command displays OSPF neighbor states, interface, and dead timer details.

Full explanation →

189

MCQmedium

An administrator wants to configure an MSDP peer relationship on a Junos device and ensure that the MD5 password authentication is applied to the TCP session. Where is the MD5 authentication key configured for an MSDP peer?

A.set system authentication-key <key>

B.set protocols pim peer <address> authentication-key <key>

C.set protocols msdp peer <address> authentication-key <key>

D.set routing-options msdp authentication-key <key>

AnswerC

This configures the MD5 password for the TCP connection to the specified MSDP peer.

Why this answer

MSDP authentication keys are configured under the specific MSDP peer statement using the authentication-key option.

Full explanation →

190

MCQmedium

You are configuring a policer and want to specify the rate in terms of bits per second. Which keyword is used to define the bandwidth limit in the policer configuration?

A.peak-rate

B.rate-limit

C.transmit-rate

D.bandwidth-limit

AnswerD

bandwidth-limit specifies the committed rate in bits per second.

Why this answer

Policer bandwidth limits in Junos are defined using the bandwidth-limit or burst-size-limit keywords.

Full explanation →

191

MCQhard

An engineer is configuring OSPFv3 on Junos OS and notices that adjacencies are failing to form over a point-to-point link. Reviewing the interface configuration, what is a mandatory requirement for OSPFv3 interface configuration that differs fundamentally from OSPFv2?

A.Disabling IPv6 stateless address autoconfiguration (SLAAC) on the underlying physical interface.

B.Enabling the interface with an IPv6 link-local address for neighbor discovery.

C.Explicit manual configuration of the Router ID using the global router-id statement.

D.Defining explicit neighbor statements using the neighbor command for all point-to-point links.

AnswerB

OSPFv3 runs directly over IPv6 and uses link-local addresses as source addresses for hello packets and neighbor formation.

Why this answer

OSPFv3 relies heavily on IPv6 link-local addresses for neighbor discovery and next-hop resolution, and interfaces must have an IPv6 link-local address assigned.

Full explanation →

192

Multi-Selecthard

An engineer is troubleshooting a multicast forwarding issue where data from a specific source is not reaching receivers in a remote PIM sparse-mode domain. Which THREE operational commands and diagnostic steps should be used to verify the multicast forwarding state and RPF path on a Junos router? (Choose three)

Select 3 answers

A.Run 'show ospf database multicast' to verify LSA type 6 propagation.

B.Run 'show pim join' to inspect upstream neighbor information and verify the RPF interface for the source.

C.Run 'show igmp group' to verify that receivers have successfully joined the multicast group on the local interface.

D.Run 'show bgp summary multicast-unicast' to verify BGP routing tables for multicast RPF checks.

E.Run 'show multicast route' to verify if (S,G) or (*,G) entries exist and check packet forwarding counters.

AnswersB, C, E

The 'show pim join' command displays PIM join state and confirms the upstream RPF neighbor toward the source or RP.

Why this answer

To troubleshoot multicast traffic forwarding and RPF failures in Junos, operators check the multicast forwarding cache using 'show multicast route', verify the upstream RPF neighbor using 'show pim join', and inspect IGMP membership states.

Full explanation →

193

Multi-Selecthard

You are troubleshooting a power budget shortfall on an EX4300 switch where multiple PoE devices are failing to power up. Which TWO actions can you take to resolve or mitigate this power deficit? (Choose two.)

Select 2 answers

A.Disable LLDP-MED globally to force all phones to draw maximum class power.

B.Enable RSTP root guard on all voice interfaces.

C.Configure critical IP phone ports with a high PoE priority so they are not shut down during a power deficit.

D.Configure power consumption limits manually on ports using consumption mode or explicit wattage limits.

E.Convert all access ports to trunk ports.

AnswersC, D

Setting high priority prevents critical ports from being shed when power budgets are exceeded.

Why this answer

Power deficits can be managed by adjusting interface priorities or changing the PoE management mode/allocations.

Full explanation →

194

MCQhard

You are designing an EVPN network with active-active multi-homing. A host sends traffic to a multi-homed PE. The PE receives the traffic on a designated link. How does EVPN suppress unnecessary flooding across the core for unknown unicast traffic originating from a multi-homed site?

A.By utilizing Spanning Tree Protocol to block redundant ports across the core.

B.By dropping all packets with unknown destination MAC addresses at the ingress leaf.

C.By enforcing ingress replication drop filters on Type 3 routes.

D.By dynamically learning MAC addresses via control-plane Type 2 routes, turning unknown unicast into known unicast.

AnswerD

Control-plane MAC learning via Type 2 routes ensures remote PEs know the MAC location immediately, avoiding data-plane flooding.

Why this answer

EVPN suppresses unknown unicast flooding by performing MAC learning via control-plane advertisement (Type 2 routes) upon first contact, so subsequent traffic is unicast-forwarded rather than flooded.

Full explanation →

195

MCQmedium

An engineer needs to prevent Type-5 LSAs from entering an OSPF stub area while still allowing external routes to be reached via a default route. Which configuration statement under [edit protocols ospf area] achieves this on a Juniper device?

A.set totally-stubby

B.set stub default-metric 10

C.set stub

D.set nssa default-lsa type-7

AnswerC

The 'stub' command under the area hierarchy defines the area as a stub, blocking external LSAs and injecting a default route.

Why this answer

Configuring 'stub' without the 'no-summaries' keyword makes the area a standard stub area, which blocks Type-5 LSAs and injects a default route (Type-3 summary default).

Full explanation →

196

Multi-Selectmedium

Which TWO statements are correct regarding IGMP version 2 (IGMPv2) features compared to IGMPv1? (Choose two)

Select 2 answers

A.IGMPv2 relies entirely on group membership timeout for leaving groups.

B.IGMPv2 includes a querier election mechanism among multiple routers on a subnet.

C.IGMPv2 introduces explicit Leave Group messages to reduce leave latency.

D.IGMPv2 supports source-specific filtering lists (include/exclude).

E.IGMPv2 requires PIM sparse-mode to be enabled on all participating hosts.

AnswersB, C

IGMPv2 elects the router with the lowest IP address as the querier.

Why this answer

IGMPv2 introduced explicit leave messages (Leave Group) and a designated querier election mechanism, unlike IGMPv1 which relied on timeout expiration.

Full explanation →

197

Multi-Selecthard

An enterprise network uses MBGP (Multicast BGP) alongside PIM sparse-mode. Which THREE statements accurately describe the function of MBGP in a multicast environment? (Choose three)

Select 3 answers

A.MBGP allows the multicast routing topology to be different from the unicast routing topology.

B.MBGP replaces the function of MSDP by sharing source-active states between RPs.

C.MBGP forwards multicast data packets directly across autonomous systems.

D.MBGP uses Address Family Identifier (AFI) and Subsequent Address Family Identifier (SAFI) extensions.

E.MBGP provides the routing path information used by PIM routers to perform RPF checks.

AnswersA, D, E

Because MBGP maintains separate tables (via IPv4 multicast AFI/SAFI), paths can be optimized differently from unicast.

Why this answer

MBGP provides separate multicast routing information for RPF checks, uses address families (AFI/SAFI), and allows multicast topology to differ from unicast topology.

Full explanation →

198

MCQmedium

Which component of a scheduler configuration determines how memory resources are allocated among different queues?

A.buffer-size

B.drop-profile-map

C.transmit-rate

D.priority

AnswerA

buffer-size allocates memory queue space.

Why this answer

The buffer-size parameter determines memory buffer allocation for each queue in a scheduler configuration.

Full explanation →

199

MCQmedium

An engineer is verifying MAC learning behavior in an EVPN instance. A remote host's MAC address is learned via BGP Type 2 routes, but when the local host sends traffic to it, the packet drops. The engineer runs 'show route table bgp.evpn.0' and sees the route. What is the most likely reason the packet is dropping in the data plane?

A.The data-plane VNI mapping or tunnel next-hop resolution is incomplete.

B.Type-4 routes have not been exchanged yet.

C.The BGP route target import policy is rejecting the route.

D.The local router's BGP router ID is misconfigured.

AnswerA

Control-plane success does not guarantee data-plane tunnel setup; VNI bindings and IP reachability to the remote VTEP must be valid.

Why this answer

Even if the control plane has learned the EVPN Type 2 route, if the data plane tunnel encapsulation (such as a missing VNI mapping or incomplete VXLAN next-hop resolution) is misconfigured, data plane forwarding will fail.

Full explanation →

200

MCQmedium

You are designing a routing policy to tag routes being redistributed from OSPF into BGP. Where in the routing policy should the tag match condition be placed?

A.from protocol ospf tag <value>

B.from route-tag <value>

C.from ospf-tag <value>

D.term match-tag value <value>

AnswerC

In Junos routing policies, 'ospf-tag' is the correct match condition under the 'from' statement to evaluate OSPF route tags.

Why this answer

When matching OSPF route tags in routing policies, the term must include the 'ospf-tag' match condition within the 'from' block.

Full explanation →

201

MCQeasy

Which configuration statement enables PIM sparse-mode globally across all interfaces in a Junos routing instance?

A.set routing-options multicast pim-enable

B.set protocols multicast enable

C.set protocols pim interface all

D.set protocols pim interface all mode sparse

AnswerC

Enabling PIM on 'interface all' turns on PIM sparse-mode across all router interfaces.

Why this answer

In Junos, PIM can be enabled on individual interfaces or globally by specifying 'interface all' under protocols pim.

Full explanation →

202

Multi-Selectmedium

Which THREE methods are valid for marking packet headers using CoS rewrite rules in Junos? (Choose three)

Select 3 answers

A.exp

B.ieee-802.1

C.dscp

D.vlan-id

E.mpls-ttl

AnswersA, B, C

exp rewrite rules modify MPLS EXP bits.

Why this answer

Rewrite rules can modify DSCP, EXP, and IEEE 802.1p fields.

Full explanation →

203

MCQmedium

You need to ensure that an OSPF interface does not send or receive OSPF hellos, but its subnet is still advertised into the OSPF domain. What configuration achieves this in Junos?

A.set protocols ospf area 0.0.0.0 interface em0.0 silent

B.set protocols ospf passive-interface em0.0

C.set protocols ospf area 0.0.0.0 interface em0.0 disable-hellos

D.set protocols ospf area 0.0.0.0 interface em0.0 passive

AnswerD

The 'passive' keyword configures the OSPF interface as passive.

Why this answer

Configuring an interface as passive prevents OSPF protocol packets from being sent or received on that interface while still including its network prefix in the routing updates.

Full explanation →

204

Multi-Selecteasy

Which TWO security features can be configured on Juniper EX switches to prevent DHCP spoofing and ARP poisoning attacks on Layer 2 access ports? (Choose two)

Select 2 answers

A.Storm control

B.BPDU guard

C.DHCP snooping

D.MACsec encryption

E.Dynamic ARP Inspection (DAI)

AnswersC, E

DHCP snooping builds a binding database to prevent rogue DHCP servers and IP spoofing.

Why this answer

DHCP snooping and Dynamic ARP Inspection (DAI) prevent DHCP spoofing and ARP poisoning respectively.

Full explanation →

205

MCQmedium

Which command displays the configured scheduler maps and their association with forwarding classes on a Junos device?

A.show class-of-service queue

B.show class-of-service scheduler-map

C.show class-of-service forwarding-class

D.show configuration class-of-service schedulers

AnswerB

This command displays scheduler map configurations.

Why this answer

The show class-of-service scheduler-map command displays details of scheduler maps and queue associations.

Full explanation →

206

Multi-Selectmedium

Which THREE parameters are typically included or evaluated when configuring and verifying BGP EVPN peer sessions on Junos OS devices? (Choose three)

Select 3 answers

A.Route targets (import and export) to control the exchange of EVPN routes between routing instances.

B.RSVP bandwidth reservation for the BGP TCP session.

C.Spanning tree priority configuration for the BGP peering interface.

D.BGP family evpn signaling (or l2vpn evpn) address family activation.

E.Route Distinguisher (RD) to ensure unique route identification per EVPN instance.

AnswersA, D, E

Route targets determine which EVPN routes are imported into or exported from an EVPN routing instance.

Why this answer

BGP EVPN peering requires the BGP neighbor IP/address family configuration, Route Targets for import/export control, and Route Distinguishers for uniqueness within the routing instance.

Full explanation →

207

MCQmedium

An engineer notices that a Junos device is not installing a BGP route into the forwarding table because the BGP next hop is unresolved. Which tool or command can be used to troubleshoot how the BGP next hop is being resolved in the Junos routing table?

A.show route resolution

B.show bgp summary

C.show bgp group

D.show route advertising-protocol bgp

AnswerA

The show route resolution command specifically details how Junos resolves next hops through active routing table entries.

Why this answer

To check BGP next-hop resolution, the 'show route resolution' command displays how next hops are resolved via the routing table (RIB-local), showing whether an active IGP or static route covers the BGP next-hop IP address.

Full explanation →

208

MCQmedium

An engineer is configuring QinQ (802.1ad) tunneling on a Juniper EX Series switch to transport customer VLANs across a service provider core. The customer-facing access port receives tagged frames with outer VLAN ID 100 and inner VLAN ID 200. Which configuration statement correctly defines the interface encapsulation and VLAN mapping?

A.set interfaces ge-0/0/1 encapsulation flexible-ethernet-services and set interfaces ge-0/0/1 unit 0 family ethernet-switching vlan-tagging

B.set interfaces ge-0/0/1 encapsulation vlan-stacking and set interfaces ge-0/0/1 unit 0 family ethernet-switching input-vlan-map push and set interfaces ge-0/0/1 unit 0 family ethernet-switching output-vlan-map pop

C.set interfaces ge-0/0/1 encapsulation flexible-ethernet-services and set interfaces ge-0/0/1 unit 0 family ethernet-switching interface-mode access

D.set interfaces ge-0/0/1 encapsulation qinq-access and set interfaces ge-0/0/1 unit 0 family ethernet-switching vlan-members 100

AnswerB

vlan-stacking encapsulation with input-vlan-map push and output-vlan-map pop correctly handles Q-in-Q encapsulation on Juniper EX switches.

Why this answer

To configure Q-in-Q tunneling on Juniper switches, the customer-facing port requires 'flexible-ethernet-services' encapsulation and a 'vlan-map' configuration that maps the incoming outer VLAN to the provider core VLAN.

Full explanation →

209

Multi-Selectmedium

An enterprise network administrator is configuring PIM Sparse-Mode and needs to control which multicast groups are allowed to be joined or forwarded through the network. Which THREE methods or configuration elements can be used in Junos OS to filter multicast join messages or control group memberships? (Choose three)

Select 3 answers

A.Configure a firewall filter family inet filter-name on the loopback interface matching destination port 639.

B.Apply a bridge-domain filter under [edit bridge-domains] blocking destination MAC address 01:00:5E:00:00:01.

C.Configure an IGMP access policy under [edit protocols igmp interface <name> policy] to restrict local host group memberships.

D.Apply a policy statement under [edit protocols pim join-policy] to filter incoming (*,G) and (S,G) joins.

E.Configure SSM mapping using [edit protocols igmp ssm-mapping] to translate standard IGMPv2 joins into SSM range joins.

AnswersC, D, E

IGMP policies can be applied on interfaces to control which groups directly connected hosts are permitted to join.

Why this answer

In Junos, multicast group filtering can be achieved by applying policy frameworks to PIM joins, configuring IGMP access-lists or policies to restrict host joins, and setting SSM mapping filters.

Full explanation →

210

MCQmedium

An administrator applies a policy containing 'as-path-prepend "65001 65001"' to outbound BGP updates sent to an external provider. What is the primary objective of this configuration?

A.To force the external peer to drop all updates due to an AS path loop check failure.

B.To enable BGP multipath load balancing across multiple external links.

C.To establish a confederation sub-AS relationship with the external provider.

D.To artificially increase the AS path length attribute to make this path less preferred by inbound traffic.

AnswerD

AS path prepending is a standard traffic engineering technique to make a route less attractive by lengthening the AS path.

Why this answer

Prepending the local AS number multiple times increases the AS path length attribute, making the path less desirable to external peers and manipulating inbound traffic engineering.

Full explanation →

211

MCQmedium

You want to tune OSPF convergence by reducing the hello and dead intervals on a point-to-point interface. Which configuration is valid?

A.set protocols ospf area 0.0.0.0 timers hello-interval 1

B.set interfaces xe-0/0/0.1 ospf hello-interval 1

C.set protocols ospf hello-interval 1 dead-interval 4

D.set protocols ospf area 0.0.0.0 interface xe-0/0/0.1 hello-interval 1

AnswerD

Hello and dead intervals are configured per interface under the OSPF area.

Why this answer

OSPF interface timers such as hello-interval and dead-interval are configured directly under the interface hierarchy within protocols ospf.

Full explanation →

212

MCQeasy

Which Junos command displays the LLDP neighbor information specifically for a single interface, such as ge-0/0/1?

A.show lldp neighbor interface ge-0/0/1

B.show protocols lldp interface ge-0/0/1 neighbors

C.show interfaces lldp neighbor ge-0/0/1

D.show lldp interface ge-0/0/1 status

AnswerA

show lldp neighbor interface <name> restricts output to the specified port.

Why this answer

show lldp neighbor interface allows filtering LLDP neighbors by specific interface names.

Full explanation →

213

Multi-Selecthard

Which THREE parameters must match between OSPF routers for an adjacency to successfully form on a point-to-point network? (Choose three)

Select 3 answers

A.Interface IP address subnets

B.Authentication parameters

C.Router ID

D.Hello and dead intervals

E.Area ID

AnswersB, D, E

Authentication keys and type must match if authentication is enabled.

Why this answer

For OSPF neighbors to form adjacencies, area ID, hello/dead intervals, and authentication settings (if enabled) must match. MTU size can also cause stuck in ExStart/Exchange if mismatched and enabled.

Full explanation →

214

MCQmedium

You are configuring Q-in-Q tunneling on an MX Series router where customer frames arrive with VLAN tag 100, and you need to encapsulate them with a service provider outer VLAN tag 3000 using 'vlan-map'. Where is the VLAN map applied?

A.Under the routing-instance bridge-domain configuration

B.Under the logical interface unit configuration using input/output vlan-map

C.Under protocols l22-control configuration hierarchy

D.Under the physical interface encapsulation statement

AnswerB

VLAN maps for tag manipulation are applied under logical interface units.

Why this answer

VLAN maps or rewriting rules are applied on the logical interface (subinterface) inbound or outbound directions.

Full explanation →

215

MCQmedium

When configuring a BGP confederation, how are external peers outside the confederation affected by the internal sub-AS structure?

A.They require explicit configuration of every member AS in their own EBGP import filters.

B.They see all member AS numbers prepended individually in the AS path.

C.They see only the top-level confederation AS number in the AS path attribute.

D.They reject all updates originating from a confederation due to AS path validation failures.

AnswerC

Confederation encapsulation hides internal sub-AS routing details from external ASNs.

Why this answer

External peers outside the confederation see only the top-level confederation AS number, as internal member AS numbers are stripped when exiting the confederation boundary.

Full explanation →

216

MCQmedium

An engineer needs to view the MSDP Source-Active (SA) cache on a Junos router to verify which sources are currently active across different PIM domains. Which operational command should be executed?

A.show multicast source-cache

B.show bgp msdp active

C.show pim source-active

D.show msdp source-active

AnswerD

This command shows the active source entries learned or advertised via MSDP.

Why this answer

The 'show msdp source-active' command displays the contents of the MSDP SA cache.

Full explanation →

217

Multi-Selectmedium

Which TWO statements are true regarding Source-Specific Multicast (SSM) operation in Junos? (Choose two)

Select 2 answers

A.SSM eliminates the need for Rendezvous Points (RPs) and MSDP.

B.SSM requires PIM dense-mode to flood traffic to all routers.

C.SSM operates within the 224.0.0.0/24 multicast range.

D.SSM uses (*,G) shared trees exclusively for distribution.

E.SSM requires IGMPv3 on receiver interfaces to support source-filter membership reports.

AnswersA, E

Since receivers join directly to (S,G), RPs and MSDP are not needed for SSM.

Why this answer

SSM uses the 232.0.0.0/8 range and requires IGMPv3 (or MLDv2 for IPv6) to allow hosts to specify source addresses directly, bypassing the need for an RP.

Full explanation →

218

MCQeasy

Which EVPN route type is responsible for establishing ingress replication lists for Broadcast, Unknown Unicast, and Multicast (BUM) traffic?

A.Route Type 3

B.Route Type 5

C.Route Type 4

D.Route Type 1

AnswerA

Route Type 3 establishes the inclusive multicast tree/replication list for BUM traffic.

Why this answer

Route Type 3 (Inclusive Multicast Ethernet Tag Route) is used to build the peer list for BUM traffic distribution using ingress replication (head-end replication).

Full explanation →

219

MCQhard

A Junos router receives a BGP route containing multiple extended and large communities. The administrator writes a routing policy to filter routes based on large communities. Which format is used to define a large community in Junos policy-options?

A.as-number:identifier

B.large-community:global_administrator:local_data1:local_data2

C.target:as-number:identifier

D.ipv4-address:identifier

AnswerB

Junos uses the three-part format for defining large communities.

Why this answer

Large communities in Junos policy-options are defined using the format large-community:global_administrator:local_data1:local_data2.

Full explanation →

220

MCQeasy

Which EVPN route type is known as the Ethernet Segment Route and is advertised by a PE router to signal its connectivity to a multi-homed Ethernet segment?

A.Route Type 2

B.Route Type 3

C.Route Type 1

D.Route Type 4

AnswerD

Route Type 4 is the Ethernet Segment Route used for DF election.

Why this answer

EVPN Route Type 4 is the Ethernet Segment Route, used for discovering other PEs attached to the same Ethernet segment and executing the Designated Forwarder (DF) election.

Full explanation →

221

Multi-Selectmedium

Which TWO options are valid configurable parameters under an access profile in Junos OS? (Choose two)

Select 2 answers

A.radius-server-group

B.virtual-router-instance

C.ethernet-switching-options

D.storm-control

E.accounting

AnswersA, E

Correct. Radius server groups are defined under access profiles.

Why this answer

Access profiles contain RADIUS server groups, accounting parameters, and authentication order settings.

Full explanation →

222

MCQeasy

Which BGP community is a well-known transitive community used to prevent a route from being advertised outside of a local autonomous system?

A.no-peer

B.local-as

C.no-export

D.no-advertise

AnswerC

The NO_EXPORT community prevents routes from being advertised outside the local autonomous system.

Why this answer

The NO_EXPORT well-known community instructs a BGP peer not to advertise the affected route to any external BGP peers.

Full explanation →

223

MCQmedium

You want to change the OSPF reference bandwidth globally on a Junos routing device to accurately calculate costs for high-speed interfaces. Where is this configured?

A.set system ospf reference-bandwidth 10g

B.set protocols ospf reference-bandwidth 10g

C.set protocols ospf area 0.0.0.0 reference-bandwidth 10g

D.set routing-options ospf reference-bandwidth 10g

AnswerB

This command sets the OSPF reference bandwidth globally to 10 Gbps.

Why this answer

The reference bandwidth for OSPF is configured globally under the protocols ospf hierarchy using the reference-bandwidth statement.

Full explanation →

224

Multi-Selecthard

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

Select 2 answers

A.Shapers are typically implemented on egress interfaces

B.Policers are primarily configured on egress interfaces for shaping purposes

C.Shapers buffer exceeding traffic to smooth out bursts over time

D.Policers buffer exceeding traffic in dedicated memory queues

E.Shapers operate without drop profiles or buffer allocation

AnswersA, C

Shaping is an egress traffic conditioning mechanism.

Why this answer

Shapers buffer excess traffic to smooth out bursts, whereas policers drop or mark exceeding traffic immediately.

Full explanation →

225

MCQhard

An enterprise network uses Q-in-Q tunneling over an MX Series provider network. Customer BPDUs must pass transparently across the provider core without being processed by the provider's own VSTP/MSTP instances. Which feature must be enabled on the provider switch access ports to achieve this?

A.MSTP region boundary enforcement

B.BPDU filter across all bridging domains

C.VLAN translation swapping on inner tags

D.Layer 2 Protocol Tunneling (L2PT)

AnswerD

L2PT encapsulates BPDUs into proprietary multicast frames at the ingress edge and strips them at the egress edge.

Why this answer

Layer 2 protocol tunneling (L2PT) or BPDU tunneling is required to encapsulate L2 control frames (like STP BPDUs) into multicast destination MAC addresses so they cross the core transparently.

Full explanation →

Juniper Networks Enterprise Routing and Switching, Professional (JNCIP-ENT, JN0-650) (JNCIP-ENT) (JNCIP-ENT) — Questions 151–225