JNCIP-ENT Practice Test 2 — 30 Questions

Question 1

A network administrator wants to advertise an aggregate BGP route while suppressing the more specific component routes from being sent to external peers. Which Junos routing-options configuration achieves this?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Configure the aggregate route with the 'summary-only' parameter under routing-options bgp.. Using the 'aggregate' statement with the 'summary-only' option generates the aggregate prefix and suppresses all component specific routes.

Answer

Enable BGP dampening on the aggregate route and disable it on the component routes.

Answer

Apply a routing policy that sets the NO_EXPORT community on all component routes.

Answer

Configure an aggregate route with the 'discard' policy and apply an export policy that drops component routes.

Question 2

You want to configure voice VLAN functionality on a Juniper EX switch so that IP phones automatically place voice traffic into VLAN 50 while passing PC data through unchanged. Which feature should you configure?

Accepted Answer

LLDP-MED with voice VLAN assignment. Voice VLAN feature on EX switches automatically assigns voice traffic from known MAC OUIs to the designated voice VLAN.

Answer

MAC-based RADIUS dynamic VLAN assignment

Answer

Layer 2 protocol tunneling (L2PT)

Answer

IEEE 802.1X supplicant authentication

Question 3

Which protocol version introduces explicit source inclusion and exclusion lists (TO_EX, TO_IN, IS_IN, IS_EX) in membership reports?

Accepted Answer

IGMPv3. IGMPv2 supports basic group membership, whereas IGMPv3 introduces source-filtering capabilities allowing hosts to specify include or exclude source lists.

Answer

IGMPv2

Answer

IGMPv4

Answer

IGMPv1

Question 4

You are configuring a BGP Route Reflector (RR) in a Junos environment. To prevent routing loops within the iBGP cluster, what mechanism does the route reflector use to track the path of reflected routes?

Accepted Answer

Cluster List and Originator ID attributes. Route reflectors use the 'Originator ID' (a 4-byte attribute containing the router ID of the route originator) and the 'Cluster List' (a sequence of cluster IDs through which the route has passed) to prevent routing loops.

Answer

MED comparison and router ID tie-breakers

Answer

AS Path prepending and local preference manipulation

Answer

TTL security decrement and loose reverse path forwarding

Question 5

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

Accepted Answer

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

Answer

show route table ospf.0 neighbor

Answer

show protocols ospf neighbors

Answer

show ospf adjacency

Question 6

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

Accepted Answer

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

Answer

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

Answer

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

Answer

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

Question 7

An administrator configures BGP dampening on a Junos router to mitigate the impact of flapping routes. When a route exceeds the reuse threshold after being suppressed, what happens to its penalty value?

Accepted Answer

The penalty value continues to decay exponentially until it drops to zero.. When a dampened route's penalty decays below the reuse threshold, the route becomes eligible again, and its penalty continues to decay exponentially toward zero.

Answer

The penalty value is locked at the reuse threshold value indefinitely.

Answer

The penalty value is doubled to discourage further flapping.

Answer

The penalty value is instantly reset to zero.

Question 8

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

Accepted Answer

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

Answer

Change the OSPF hello timer interval via routing policy.

Answer

Alter the OSPF router ID of neighboring routers.

Answer

Change the OSPF area ID of external routes dynamically.

Question 9

When configuring advanced Q-in-Q tunneling on Juniper MX Series routers, which THREE encapsulation or tagging parameters must be correctly aligned between the customer edge and provider edge interfaces? (Choose three)

Accepted Answer

VLAN action rules (pop, push, or swap). Q-in-Q alignment requires matching flexible-vlan-tagging, TPID values (EtherType), and VLAN tag preservation/manipulation rules.

Answer

MSTP region name configuration

Answer

IGMP snooping version compatibility

Question 10

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

Accepted Answer

Route Type 3. 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).

Answer

Route Type 5

Answer

Route Type 4

Answer

Route Type 1

Question 11

How do you examine the specific OSPF routing table entries learned via OSPF on a Junos device?

Accepted Answer

show route protocol ospf. The 'show route protocol ospf' command displays routes learned specifically through the OSPF routing protocol.

Answer

show protocols ospf route-table

Answer

show ospf routes

Answer

show ip route ospf

Question 12

Which THREE configuration tasks are required when implementing OSPFv3 on Junos devices? (Choose three)

Accepted Answer

Enabling OSPFv3 under the protocols ospf3 hierarchy. Configuring OSPFv3 requires specifying protocols ospf3, configuring areas, and enabling OSPFv3 on specific interfaces (IPv6 enabled).

Answer

Configuring BGP autonomous system numbers for OSPFv3 operation

Answer

Enabling IPv4 address families inside protocols ospf3

Question 13

Which THREE statements describe the behavior of LLDP-MED capability on Junos EX Series switches? (Choose three.)

Accepted Answer

It automates network policy configuration for voice, video, and guest VLANs.. LLDP-MED enables advanced capabilities like device location, inventory management, and network policies for endpoints.

Answer

It replaces the need for Ethernet switching entirely by converting access ports into routed links.

Answer

It requires OSPFv3 to be running on all connected IP phones.

Question 14

An administrator notices that broadcast, unknown unicast, and multicast (BUM) traffic sent from a local host is looping back to the originating multi-homed PE when using an all-active Ethernet segment. Which mechanism prevents this loop in EVPN?

Accepted Answer

EVPN Split Horizon filtering using ESI labels. EVPN uses Split Horizon filtering via the ESI Label Extended Community or local split-horizon checks to ensure that BUM traffic received from a remote PE on a shared Ethernet segment is not sent back out to the same segment.

Answer

BGP Best Path Selection algorithm

Answer

Designated Forwarder (DF) election

Answer

Spanning Tree Protocol (STP) root guard

Question 15

Which TWO options are valid authentication methods that can be specified in the 'authentication-order' statement on an EX Series switch interface? (Choose two)

Accepted Answer

mac-radius. On Juniper EX Series switches, the 'authentication-order' statement under an interface (or globally) accepts authentication methods such as 'dot1x', 'mac-radius', and 'captive-portal'. Option D (dot1x) is correct because IEEE 802.1X is a supported access-control authentication method that can be listed in the authentication order to authenticate supplicants via an AAA server. Option A (mac-radius) is correct because MAC RADIUS authentication is also a supported method, allowing the switch to authenticate a device by its MAC address against a RADIUS server. Option B (kerberos) is not a valid authentication-order method on EX switches, as Kerberos is not implemented as an interface authentication method there. Option C (tacacs-plus) is not valid because TACACS+ is an AAA protocol used for administrative login/authorization, not a client authentication method in the interface authentication-order list. Option E (ldap-direct) is not valid because EX switches do not support a direct LDAP authentication method in the authentication-order statement; LDAP would be reached through a RADIUS server instead.

Answer

kerberos

Answer

tacacs-plus

Answer

ldap-direct

Question 16

You are configuring a captive portal on an EX Series switch. You want to ensure that specific management traffic and critical server subnets are accessible to clients *before* they authenticate through the captive portal. Which configuration feature accomplishes this?

Accepted Answer

Captive portal firewall exemption filters or walled garden (bypass) configuration.. Pre-authentication access lists or firewall filters / bypass lists allow traffic to specific destinations before captive portal authentication occurs.

Answer

RADIUS dynamic authorization profiles with pre-auth attributes.

Answer

Global access profile authentication-bypass statements.

Answer

Static MAC bypass configuration under the protocols dot1x hierarchy.

Question 17

Which THREE parameters are part of the standard Junos BGP route selection algorithm prior to evaluating the router ID? (Choose three)

Accepted Answer

Weight (local to the router). Before router ID, Junos evaluates Weight, Local Preference, AS path length, Origin, MED, and IBGP vs EBGP preference.

Answer

Cluster List length

Answer

Originator ID value

Question 18

You want to apply a rewrite rule on an outgoing interface to remark the DSCP bits of packets leaving your Juniper router. Where must this rewrite rule be applied within the CoS hierarchy?

Accepted Answer

[edit class-of-service interfaces]. Rewrite rules in Junos are applied on egress interfaces under the interfaces statement within the class-of-service configuration hierarchy.

Answer

[edit firewall]

Answer

[edit routing-options]

Answer

[edit class-of-service classifiers]

Question 19

An administrator configures EVPN with VXLAN encapsulation and wants to ensure that interfaces assigned to bridge domains drop frames whose source MAC address is not learned or is unauthorized. Which feature should be enabled?

Accepted Answer

MAC security / MAC limit with drop action. Configuring MAC limit or bpdu protection/port security features on access interfaces prevents unauthorized MAC learning, while EVPN sticky MAC features can lock MACs to specific interfaces.

Answer

Ingress replication disabling

Answer

BGP route filtering

Answer

EVPN Route Type 4 filtering

Question 20

You are troubleshooting an issue where an 802.1X supplicant on a Windows client fails to connect to an EX Series switch port. The switch logs show 'EAPOL-TIMEOUT' errors. What does this error indicate?

Accepted Answer

The switch did not receive an EAPOL response from the client after sending an EAPOL request.. An EAPOL-TIMEOUT error indicates that the switch sent an EAPOL packet (such as EAPOL-Request/Identity) but did not receive a response from the client within the timeout window.

Answer

The RADIUS server took too long to validate the client credentials and dropped the session.

Answer

The switch port's operational mode reverted from access to trunk, dropping EAPOL frames.

Answer

The client sent an invalid EAP message that failed integrity checks.