JNCIA-DevOps NETCONF And XML API — Timed 15 Questions

Question 1

You want to retrieve only the system hostname from the Junos running configuration using NETCONF. Which filtering technique is most efficient?

Accepted Answer

Subtree filtering using XML element tags matching the configuration hierarchy. Tag-based filtering allows requesting specific configuration hierarchies by including empty container tags in the <get-config> request.

Answer

XPath expression filtering via the select attribute

Answer

Regular expression pattern matching within the <filter> attribute

Answer

Retrieving the entire configuration and parsing it locally with a Python script

Question 2

You need to commit a candidate configuration change on a Junos device via NETCONF with a confirmed commit timeout of 5 minutes. Which XML payload structure is correct?

Accepted Answer

5

. The RPC accepts a tag and a element to specify rollback timing.

Answer

Answer

Answer

Question 3

You are troubleshooting a NETCONF session where the client sent an improperly formatted XML payload. Where would you expect to find detailed error logging related to this malformed XML request on the Junos device?

Accepted Answer

NETCONF traceoptions output file or /var/log/messages. Junos logs NETCONF and XML API activity, including parsing errors, into the traceoptions log file if configured, or general system logs.

Answer

/var/log/netconf.log

Answer

/var/db/config/juniper.conf.gz

Answer

/etc/netconf/errors.xml

Question 4

Which command or tool on a Junos device verifies that the NETCONF subsystem is enabled and listening for SSH connections?

Accepted Answer

show system services netconf ssh. NETCONF over SSH runs as a subsystem on Junos and can be verified via system services configuration or operational commands.

Answer

show netconf settings

Answer

show xml-api status

Answer

show netconf status connections

Question 5

In Junos XML API, what is the XML namespace associated with Junos-specific RPCs and operational tags?

Accepted Answer

http://xml.juniper.net/junos/*/junos-rpc. Junos XML API elements use specific namespaces like http://xml.juniper.net/junos/12.1X46/junos-sw for software or general rpc namespaces.

Answer

http://www.cisco.com/ns/yang/cisco-se

Answer

urn:juniper:params:xml:ns:netconf:base:1.0

Answer

urn:ietf:params:xml:ns:netconf:base:1.0

Question 6

You are configuring NETCONF traceoptions on a Junos device to debug an XML parsing issue. Which configuration statement enables logging of all NETCONF protocol messages to a file named 'netconf-debug.log'?

Accepted Answer

set system services netconf traceoptions file netconf-debug.log
set system services netconf traceoptions flag all. Traceoptions under the netconf system services hierarchy control logging of NETCONF traffic.

Answer

set protocols netconf traceoptions file netconf-debug.log flag detail

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set security netconf logging file netconf-debug.log

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set system netconf trace file netconf-debug.log level debug

Question 7

When you issue a NETCONF <get-config> request for the running configuration, why might the request fail or return empty on certain Junos platforms?

Accepted Answer

The <running/> datastore capability is supported, but explicit locking rules or device state might restrict it if unsupported parameters are sent.. In standard NETCONF (RFC 6241), the running datastore must be supported, but Junos requires candidate configuration usage for edits; however, running is supported for reading. If it fails, it is often due to datastore capability support.

Answer

Running configuration can only be accessed using CLI commands, never NETCONF.

Answer

The <running/> tag must always be accompanied by a password attribute.

Answer

Junos does not support reading the running configuration datastore via NETCONF.

Question 8

You need to execute a Junos CLI command (such as 'show version') as an XML RPC request via NETCONF. Which RPC tag encapsulates raw Junos CLI operational commands?

Accepted Answer

show version. The tag allows executing arbitrary operational CLI commands formatted as text within the Junos XML API.

Answer

show version

Answer

show version

Answer

show version

Question 9

You want to validate a candidate configuration on a Junos device without committing it using NETCONF. Which RPC accomplishes this?

Accepted Answer

. The RPC checks the consistency and validity of a specified configuration datastore.

Answer

<test-config>

Answer

<check-config>

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<edit-config test-only="true"/>

Question 10

Which Junos XML API output format option allows requesting the output as plain text instead of structured XML?

Accepted Answer

format="text". Junos XML API allows requesting ASCII/text output format by appending the format='text' attribute to RPC requests.

Answer

output="ascii"

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encoding="plain"

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type="string"

Question 11

When retrieving operational data using the Junos XML API, how do you request pretty-printed or indented XML output?

Accepted Answer

Include the indent="true" attribute in the RPC request element.. Junos XML API supports formatting attributes such as indent="true" in RPC requests.

Answer

Add true inside the tag.

Answer

Use the NETCONF command-line flag --format-xml.

Answer

Set the environment variable JUNOS_XML_INDENT=1 in your shell.

Question 12

An administrator issues a NETCONF <get-config> request targeting the candidate datastore and includes a namespace prefix that does not match the device's loaded YANG/XML schema namespace. How does Junos respond?

Accepted Answer

The device returns an <rpc-error> indicating an invalid namespace or unrecognized element.. Mismatched or unknown namespaces in NETCONF requests result in a malformed message or invalid-element rpc-error.

Answer

The device falls back to default CLI parsing mode.

Answer

The session is immediately terminated by the SSH server.

Answer

The device automatically strips the namespace prefix and processes the request.

Question 13

Which NETCONF capability URI indicates that the server supports rolling back configuration changes to previous commit points?

Accepted Answer

Juniper specific capability strings for commit/rollback features advertised in the hello banner.. The [CORRECT] answer is D because Juniper devices advertise proprietary capability URIs in the NETCONF message that expose Junos-specific extensions, including commit/rollback functionality (e.g., http://xml.juniper.net/netconf/junos/1.0 and related URIs that enable with rollback and with rollback). The standard NETCONF rollback-on-error capability only controls error recovery during a confirmed commit, not the ability to roll back to arbitrary previous commit points. Junos implements configuration history and rollback via its own capability strings, so the correct indication is the Juniper-specific capability advertised in the hello banner.

Answer

urn:ietf:params:netconf:capability:rollback-on-error:1.0

Answer

http://xml.juniper.net/netconf/junos/1.0

Answer

urn:ietf:params:netconf:base:1.0

Question 14

You want to retrieve the software version and hardware inventory of a Junos device in a single NETCONF request. Which RPC tag combines both hardware and software details?

Accepted Answer

Executing multiple RPCs or using container elements such as and .. The and RPCs can be combined, or can be used; however, Junos provides specific RPCs like .

Answer

<get-inventory-all>

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<retrieve-device-state>

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<get-hardware-and-software>

Question 15

An automation script executes a NETCONF <edit-config> transaction that updates multiple routing protocols. You need to ensure that the changes take effect immediately without requiring a manual commit. Does NETCONF require a separate commit for candidate changes?

Accepted Answer

Yes, changes applied to the candidate datastore require an explicit RPC to become active in running configuration.. When using the candidate datastore in NETCONF, changes must be explicitly committed using the RPC unless direct datastore is used.

Answer

Yes, but the commit must be initiated via CLI because NETCONF cannot commit.

Answer

No, NETCONF automatically commits all <edit-config> changes instantly.

Answer

Only if the target datastore is explicitly set to running.