JN0-363 Practice Questions

On a Junos device, trunk ports are configured to receive and transmit tagged traffic only, while access

ports are configured to receive and transmit untagged traffic.

Reference::

Understanding Access and Trunk Interfaces, Juniper Networks Documentation

VLANs and Trunking, Juniper Networks Documentation

BGP selects the active route based on an ordered list of attributes. The correct order is:

Weight (Cisco proprietary, not listed in the options)

Local Preference

Network (route) originated from the BGP router itself

Shortest AS Path

Lowest Origin Type

Lowest MED

eBGP over iBGP paths

Closest IGP Neighbor

Lowest Router ID

The next hop is checked for reachability but is not part of the BGP decision process for selecting the

best path.

Reference:

Juniper Networks Technical Documentation on BGP

Graceful Routing Engine Switchover (GRES) and Nonstop Active Routing (NSR) are two features used

in Junos OS to provide high availability. GRES allows for the stateful failover of the Routing Engine,

and NSR allows for the continuation of packet forwarding and protocol states during a Routing Engine

switchover. These technologies ensure that peer nodes are not alerted during a switchover. VRRP and

ISSU serve different purposes and do not apply to this specific requirement.

Reference::

Juniper Networks documentation on High Availability: High Availability Features

The show bgp neighbor command in Junos OS provides a detailed description of each BGP session,

including session state, options configured, and counters for messages sent and received. This is the

command you would use to see a detailed list of all established BGP sessions.

Reference::

Juniper Networks documentation on BGP: BGP Commands

To test connectivity to a server from within a specific routing instance, you use the ping command

along with the routing-instance option to specify the routing instance from which you are pinging.

This is necessary because the routing table associated with vr3 is separate from the main routing

table, and you must explicitly tell the device to use the vr3 routing table to reach the server.

Reference::

Juniper Networks documentation on Routing Instances: Routing Instances Overview

:

When you want to advertise an interface in OSPF but not form an OSPF adjacency over that interface

(for example, towards an ISP), you can configure the interface as passive. This will advertise the

network on the interface in OSPF without sending OSPF hello packets or forming OSPF neighbor

relationships on that interface.

Reference:

Juniper Networks Technical Documentation on OSPF

OSPF Configuration Guide - Juniper Networks

The exhibit shows an aggregate route configuration for the network 172.21.0.0/22, which would

summarize the specific networks 172.21.0.0/24, 172.21.1.0/24, and 172.21.2.0/24. For an aggregate

route to be active, it must have contributing routes in the routing table. If the route is hidden, it

usually means there are no contributing routes that are active or the policy applied to the aggregate

does not match any of the specific routes. Therefore, the first step in troubleshooting would be to

verify that there are indeed active contributing routes for the aggregate to be valid.

Reference::

Juniper documentation on routing policies and aggregates: Junos OS Routing Policies, Firewall Filters,

and Traffic Policers User Guide

To influence the path taken through an autonomous system, the Multi-Exit Discriminator (MED)

attribute can be used. By setting a lower MED on R2 for routes advertised to R1 and R3, it will make

the path through R2 to the 203.0.113.0/24 network more preferable.

Reference::

Understanding BGP Path Selection, Juniper TechLibrary

BGP Attributes and Path Selection, Juniper TechLibrary

The exhibit shows the output of the command show spanning-tree bridge, which provides

information about the spanning tree status of the switch. From the output, we can see that the

switch has a bridge ID different from the root ID, which implies that this switch is not the root bridge.

The "Topology change initiator" field shows ge-0/0/14, which indicates that the last topology change

occurred on this interface, and this is also the interface used to reach the root bridge.

Reference::

Juniper Networks documentation on Spanning Tree Protocol: Understanding Spanning Tree Protocols