Juniper Networks Certified Associate Junos JNCIA-JUNOS practice test

A junior engineer needs to collect a snapshot of the current system state, including routing tables, interfaces, and configuration, for a support ticket. Which command achieves this?

Trap 1: show configuration

Only shows configuration, not operational state.

Trap 2: show interfaces

Only shows interface details.

Trap 3: show route

Only shows routing table.

A
show configuration
Why wrong: Only shows configuration, not operational state.
B
show interfaces
Why wrong: Only shows interface details.
C
request support information
Gathers comprehensive system data for troubleshooting.
D
show route
Why wrong: Only shows routing table.

Question 2easymultiple choice

A network engineer is troubleshooting a connectivity issue and wants to see the active routes in the routing table. Which Junos CLI command should they use?

Trap 1: show log messages

Shows system log messages.

Trap 2: show configuration

Shows the configuration, not routing table.

Trap 3: show interface

Shows interface status, not routing table.

A
show log messages
Why wrong: Shows system log messages.
B
show configuration
Why wrong: Shows the configuration, not routing table.
C
show interface
Why wrong: Shows interface status, not routing table.
D
show route
Displays the routing table.

Question 3hardmultiple choice

You are the network engineer for a mid-sized enterprise with a Juniper MX router running Junos. The router has two uplinks to the internet: one to ISP-A via ge-0/0/0 (10.0.0.1/30) and one to ISP-B via ge-0/0/1 (10.0.0.5/30). You have configured static default routes to both ISPs: one to 10.0.0.2 and one to 10.0.0.6. Both routes have the same preference (default 5) and metric. You enabled ECMP to load-balance outbound traffic. After testing, you notice that all traffic is being sent only to ISP-A, and none to ISP-B. You verify that both interfaces are up and that the next-hop addresses are reachable. You check the routing table and see both routes are active but with different next-hop counts. What is the most likely cause of the traffic not being load-balanced?

Trap 1: ECMP is not enabled in the forwarding-options.

ECMP is enabled, but the issue is next-hop count.

Trap 2: The route to ISP-B is not active.

Both routes are active.

Trap 3: Hash-based load balancing requires per-packet configuration.

Hash-based is default; per-packet is not typical.

A
One of the static routes resolves to multiple next hops, causing imbalance.
If one route resolves to multiple next hops, it may appear as multiple routes, skewing load balancing.
B
ECMP is not enabled in the forwarding-options.
Why wrong: ECMP is enabled, but the issue is next-hop count.
C
The route to ISP-B is not active.
Why wrong: Both routes are active.
D
Hash-based load balancing requires per-packet configuration.
Why wrong: Hash-based is default; per-packet is not typical.

Read the full NAT/PAT explanation →

Question 4mediummulti select

Which TWO attributes are used by Junos to select the active route among multiple routes to the same destination?

Trap 1: Protocol type

Protocol type is factored into preference.

Trap 2: Next hop address

Next hop is not used for selection.

Trap 3: AS path length

AS path is used in BGP but not in general route selection.

A
Metric
Lower metric is preferred when preference is equal.
B
Preference
Lower preference is preferred.
C
Protocol type
Why wrong: Protocol type is factored into preference.
D
Next hop address
Why wrong: Next hop is not used for selection.
E
AS path length
Why wrong: AS path is used in BGP but not in general route selection.

Question 5easymultiple choice

What is the default preference of a direct route in Junos?

Trap 1: 10

OSPF internal routes have preference 10.

Trap 2: 5

Static routes have preference 5.

Trap 3: 15

No standard protocol uses preference 15.

A
0
Direct routes have preference 0.
B
10
Why wrong: OSPF internal routes have preference 10.
C
5
Why wrong: Static routes have preference 5.
D
15
Why wrong: No standard protocol uses preference 15.

Read the full NAT/PAT explanation →

Question 6mediummultiple choice

A router has two routes to the same destination: one with preference 10 and metric 5, and another with preference 15 and metric 3. Which route will be installed in the forwarding table?

Trap 1: The route with metric 3.

Metric is secondary to preference.

Trap 2: Neither route is installed.

One route is installed.

Trap 3: Both routes are installed if ECMP is enabled.

ECMP requires equal preference and metric.

A
The route with preference 10.
Preference is the primary selection criterion.
B
The route with metric 3.
Why wrong: Metric is secondary to preference.
C
Neither route is installed.
Why wrong: One route is installed.
D
Both routes are installed if ECMP is enabled.
Why wrong: ECMP requires equal preference and metric.