JNCIA System Architecture 2

Question 1

What is the Routing Engine (RE) responsible for in Junos architecture?

Accepted Answer

Running routing protocols, managing configuration, and maintaining the routing table

Answer

Forwarding packets at line rate

Answer

Processing firewall filters in hardware

Answer

Managing physical interface transceivers

Question 2

What does the Packet Forwarding Engine (PFE) do in Junos?

Accepted Answer

Forwards transit packets at line rate using the forwarding table programmed by the Routing Engine

Answer

Runs routing protocols

Answer

Manages the candidate configuration

Answer

Handles system login and authentication

Question 3

In a dual-RE Junos chassis, what is the function of the backup Routing Engine?

Accepted Answer

Maintains a synchronized copy of the routing state and can take over as master if the primary RE fails

Answer

Actively forwards packets alongside the primary RE

Answer

Stores backup configuration files only

Answer

Monitors system temperature and fans

Question 4

What Junos process is responsible for managing routing protocols?

Accepted Answer

rpd (Routing Protocol Daemon)

Answer

mgd (Management Daemon)

Answer

chassisd (Chassis Daemon)

Answer

pfed (Packet Forwarding Engine Daemon)

Question 5

What is the significance of the 'inet.0' routing table in Junos?

Accepted Answer

It is the main IPv4 unicast routing table used for unicast forwarding decisions

Answer

It stores only static routes

Answer

It contains only BGP routes

Answer

It is the IPv6 routing table

Question 6

How does Junos OS ensure software modularity and fault isolation?

Accepted Answer

By running each major function as a separate process (daemon) that can restart independently without affecting others

Answer

By running all functions in a single monolithic kernel process

Answer

By using separate hardware for each routing protocol

Answer

By virtualizing the OS for each interface