JNCIA Firewall Filters

Question 1

What is the primary function of a stateless firewall filter in Junos OS?

Accepted Answer

To examine individual packets based on match conditions and apply defined actions

Answer

Junos stateless firewall filters examine each packet individually against defined match conditions and apply actions without maintaining session state.

Question 2

Which Junos CLI command correctly applies a firewall filter in the inbound direction on a logical interface?

Accepted Answer

set interfaces ge-0/0/0 unit 0 family inet filter input <filter-name>

Answer

Firewall filters are applied under the interface's logical unit and address family using the 'filter input' or 'filter output' knob.

Question 3

What are the two fundamental building blocks of a Junos OS firewall filter?

Accepted Answer

Terms and actions

Answer

A Junos firewall filter is composed of ordered terms, where each term contains match conditions (from) and actions (then).

Question 4

What happens to a packet that does not match any term in a Junos firewall filter?

Accepted Answer

It is silently discarded by an implicit default action

Answer

Junos firewall filters have an implicit discard at the end, so any packet not matched by an explicit term is silently dropped.

Question 5

Which of the following is a valid match condition that can be used in a Junos firewall filter term?

Accepted Answer

source-address

Answer

The 'source-address' match condition is a standard IPv4 match condition in a Junos inet firewall filter term.

JNCIA - Juniper Networks Certified Internet Associate Practice Test

JNCIA - Juniper Networks Certified Internet Associate Practice Test

JNCIA Firewall Filters