JNCIS-ENT Practice Test 5 — 10 Questions

Question 1

Which TCP port is used by BGP to establish communication between peers?

Accepted Answer

TCP 179. BGP operates over TCP port 179.

Answer

UDP 520

Answer

TCP 80

Answer

TCP 500

Question 2

Which THREE path attributes are classified as 'well-known mandatory'? (Choose three)

Accepted Answer

NEXT_HOP. The well-known mandatory attributes in BGP are ORIGIN, AS_PATH, and NEXT_HOP. Local Preference is well-known discretionary, and MED is optional non-transitive.

Answer

MED

Answer

LOCAL_PREF

Question 3

Which THREE statements are true regarding OSPF Graceful Restart helper mode on Juniper routers? (Choose three)

Accepted Answer

It helps prevent unnecessary SPF recalculations across the network during transient control plane restarts.. Helper mode allows routers to maintain routing tables while neighbors restart, suppressing routing churn and dropping adjacencies prematurely.

Answer

It forces the restarting router to immediately drop all data forwarding traffic.

Answer

It requires manual configuration of VRRP tracking on all loopback interfaces.

Question 4

A BGP speaker receives an UPDATE message containing a malformed attribute. According to BGP specifications, which action does the receiving router take?

Accepted Answer

Send a NOTIFICATION message and terminate the BGP session.. A malformed attribute or critical error triggers a NOTIFICATION message with an appropriate error code, followed by session teardown.

Answer

Strip the attribute and propagate the route to iBGP peers.

Answer

Send an UPDATE message requesting retransmission.

Answer

Silently ignore the attribute and install the route.

Question 5

How do you configure an interface to be point-to-point when using IS-IS?

Accepted Answer

set protocols isis interface point-to-point. You use the 'set protocols isis interface point-to-point' command to force point-to-point mode.

Answer

set protocols isis interface-type point-to-point

Answer

set interfaces <name> unit 0 family iso point-to-point

Answer

set protocols isis link-type p2p

Question 6

Which command displays the IS-IS interface parameters?

Accepted Answer

show isis interface. 'show isis interface' shows the configuration and state of IS-IS interfaces.

Answer

show isis configuration

Answer

show interfaces isis

Answer

show protocols isis interface

Question 7

Which BGP attribute is classified as 'well-known discretionary'?

Accepted Answer

LOCAL_PREF. Local Preference is a well-known discretionary attribute, meaning all BGP implementations must recognize it, but it does not have to be included in every update.

Answer

AS_PATH

Answer

ORIGIN

Answer

MED

Question 8

Which TWO statements are true regarding BGP communities in Junos? (Choose two)

Accepted Answer

Communities are optional transitive path attributes.. Communities can be standard (32-bit values represented as AS:value) or extended, and they are used to group routes for policy enforcement.

Answer

Communities replace the AS_PATH attribute entirely.

Answer

Communities are evaluated after the router ID tie-breaker.

Answer

Communities can only be applied to eBGP sessions and are stripped on iBGP.

Question 9

You are configuring multi-topology IS-IS. What does this allow?

Accepted Answer

Running separate topologies for different address families.. Multi-topology IS-IS allows for separate routing topologies for different protocol families (e.g., IPv4 and IPv6).

Answer

Load balancing over different physical paths.

Answer

Creating multiple areas within a single instance.

Answer

Increasing the maximum MTU.

Question 10

Which TWO items are required when configuring VRRP on a Juniper router interface? (Choose two)

Accepted Answer

At least one virtual IP address configured to act as the default gateway for clients.. VRRP configuration requires a Virtual Router ID (VRID) and at least one virtual IP address.

Answer

A static BGP peering session to an upstream provider.

Answer

A pre-configured GRES license on the Routing Engine.

Answer

An active LACP aggregated Ethernet bundle.