JNCIP-ENT Practice Test 1 — 10 Questions

Question 1

An engineer is troubleshooting multicast forwarding and RPF failures on a Junos routing instance. Which THREE conditions will cause a multicast RPF check failure? (Choose three)

Accepted Answer

The route to the source points towards a null or reject route.. RPF failures occur when the incoming interface for a multicast packet does not match the reverse path towards the source in the routing table, when no route exists, or when the routing table source differs.

Answer

IGMPv2 leave messages are received on an interface without active listeners.

Answer

PIM hello messages are exchanged with an incorrect hold time.

Question 2

Which THREE actions can be executed by a firewall filter policer when traffic exceeds the specified rate? (Choose three)

Accepted Answer

discard. In Junos firewall filter policers, the three valid actions that can be configured when traffic exceeds the specified rate are discard, loss-priority high, and forward. Option A (discard) is correct because the policer can simply drop out-of-profile packets, which is the most common bandwidth-limiting behavior. Option B (loss-priority high) is correct because the policer can mark excess packets with a high loss priority so downstream congestion-management (RED/WRED) drops them preferentially instead of dropping them immediately. Option D (forward) is correct because the policer can pass out-of-profile packets through while optionally setting a loss priority, allowing later devices or schedulers to handle them. Option C (reroute-lsp) is not a policer action; it is an MPLS routing action used in routing policies or forwarding-adjacency contexts, not in a policer's then statement. Option E (queue-switch) is not a valid policer action either; queue selection is handled by forwarding classes and schedulers, not by policers.

Answer

reroute-lsp

Answer

queue-switch

Question 3

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?

Accepted Answer

show route resolution. 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.

Answer

show bgp summary

Answer

show bgp group

Answer

show route advertising-protocol bgp

Question 4

What is the primary function of the RADIUS server attribute 'Tunnel-Medium-Type' (Attribute 65) when received during an 802.1X authentication exchange on an EX Series switch?

Accepted Answer

It specifies the physical transport media type for the tunnel, such as 802 (Ethernet) for VLAN assignment.. Tunnel-Medium-Type specifies the media type of the tunnel, which for VLAN assignments in Junos is typically set to 802 (Ethernet).

Answer

It defines the VLAN ID or VLAN name to which the authenticated client port should be dynamically assigned.

Answer

It determines the encryption cipher used between the switch and the RADIUS server.

Answer

It indicates the authentication protocol (PAP, CHAP, EAP) being used in the tunnel.

Question 5

Which THREE actions occur during the EVPN Designated Forwarder (DF) election process on a multi-homed Ethernet segment? (Choose three)

Accepted Answer

A Designated Forwarder is elected to forward BUM traffic from the core to the multi-homed site.. DF election uses Route Type 4 (Ethernet Segment routes) to exchange reachability, determines the forwarder based on preference and algorithms, and assigns responsibility for BUM traffic forwarding.

Answer

All participating PEs simultaneously forward BUM traffic to maximize bandwidth utilization.

Answer

MAC mobility sequence numbers are reset to zero during the election.

Question 6

A network engineer is configuring class of service on a Junos switch and wants to guarantee that the network control traffic forwarding class always has bandwidth available for routing protocol updates, even during heavy data congestion. The engineer also wants to ensure that this class is not starved by other queues. Which scheduler configuration should the engineer apply to the network control forwarding class?

Accepted Answer

A scheduler with a guaranteed transmit-rate and a high priority. A guaranteed transmit-rate reserves bandwidth for the network control forwarding class, and high priority ensures it is serviced ahead of ordinary data queues, protecting routing protocol updates during congestion without the starvation risk of strict-high priority. Low priority, excess-only rates, and strict-high with policing all fail to provide the required balance of guaranteed bandwidth and preferential servicing.

Answer

A scheduler with a strict-high priority and a policer to cap its rate

Answer

A scheduler with a low priority and a small buffer size

Answer

A scheduler with an excess transmit-rate and a low priority

Question 7

An operator configures BGP attribute value manipulation using a Junos routing policy. Specifically, the policy uses 'as-path-action prepend' combined with community matching. When is this outbound policy evaluated relative to BGP route selection?

Accepted Answer

When advertising routes to a BGP peer, after the best path has been chosen.. Outbound export policies are evaluated when advertising routes to peers, after the best path has been selected locally.

Answer

During the initial import processing from EBGP peers before next-hop resolution.

Answer

Before the best path is selected, affecting the local routing table calculation.

Answer

During the route selection algorithm right after MED comparison.

Question 8

When configuring OSPFv3, which Junos address-family hierarchy is used to enable OSPFv3 on an interface?

Accepted Answer

set protocols ospf3 area 0.0.0.0 interface xe-0/0/0.0. OSPFv3 in Junos operates within the IPv6 address family under protocols ospf3.

Answer

set protocols ospf version 3 area 0.0.0.0 interface xe-0/0/0.0

Answer

set protocols ipv6 ospf area 0.0.0.0 interface xe-0/0/0.0

Answer

set protocols ospf3 ipv6 area 0.0.0.0 interface xe-0/0/0.0

Question 9

You are deploying IP phones on an EX4300 switch. The phones require PoE+ (802.3at) and must be allocated power based on their actual consumption rather than a fixed class. Which PoE management mode should you configure on the switch?

Accepted Answer

consumption. The 'consumption' mode allocates power based on actual power draw, which is more efficient than class-based or static allocation. This is particularly useful for PoE+ devices like IP phones that may not always draw maximum power, allowing the switch to support more devices within its power budget.

Answer

class

Answer

static

Answer

priority

Question 10

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?

Accepted Answer

set protocols msdp peer

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

Answer

set system authentication-key <key>

Answer

set protocols pim peer

authentication-key

Answer

set routing-options msdp authentication-key <key>