Exam 200-901 topic 1 question 12 discussion

They are correct, I just tried it against an IOS-EX device and XML was default: SHOW VERSION OUTPUT (cut down): CiscoCSR1000v16.12.1a-1#show ver Cisco IOS XE Software, Version 16.12.01a Cisco IOS Software [Gibraltar], Virtual XE Software (X86_64_LINUX_IOSD-UNIVERSALK9-M), Version 16.12.1a, RELEASE SOFTWARE (fc2) DEFAULT CURL OUTPUT: curl -k https://192.168.2.48/restconf/ -u "admin:admin" <restconf xmlns="urn:ietf:params:xml:ns:yang:ietf-restconf"> <data/> <operations/> <yang-library-version>2016-06-21</yang-library-version> </restconf> CURL OUTPUT WHEN ACCEPT = JSON: curl -k https://192.168.2.48/restconf/ -u "admin:admin" -H "Accept: application/yang-data+json" {"ietf-restconf:restconf":{"data":{},"operations":{},"yang-library-version":"2016-06-21"}}

IOS-XE The following services are supported by the REST connector for IOS-XE. get API to send GET command to the device. Argument Description Default content_type Content type returned(xml or json) (optional) json post API to send POST command with optional payload to the device. Argument Description Default content_type Content type retorned(xml or json) (optional) json or xml Note: If the content_type option is not passed, the script will try to detect if the payload is XML, otherwise it will assume JSON. The content-type and accept headers will be set based on the detected payload or on the passed content-type. DEVAST BOOK There are two new media types defined for RESTCONF: application/yang.api+xml for XML-encoded payloads application/yang.api+json for JSON-encoded data https://pubhub.devnetcloud.com/media/rest-connector/docs/user_guide/services/iosxe.html#

Should be Json based on below source code:https://www.netconfcentral.org/modules/netconfd-pro/2021-10-13/source/cooked/ leaf restconf-default-encoding { type enumeration { enum "json" { value 0; description "Use JSON message encoding as the default."; } enum "xml" { value 1; description "Use XML message encoding as the default."; } } default "json"; description "Specifies the default response encoding to use if the incoming request does not have an indication of preferred content type (e.g., no Content-Type header, no Accept header). ";

Yep. It's C. I just ran a simple cURL query on an IOS-XE device without any Accept headers and it returned XML. I had to add the Accept: application/yang-data+json header to get JSON.

A The Cisco IOS XE REST API uses the HTTP request methods described in Table 1-2. Note All REST API requests and responses must be in JSON format. XML is not supported https://www.cisco.com/c/en/us/td/docs/routers/csr1000/software/restapi/restapi/RESTAPIintro.pdf

When a Cisco IOS XE networking device is configured using RESTCONF (REpresentational State Transfer Configuration Protocol), the default data-encoding method is JavaScript Object Notation (JSON). JSON is a lightweight data interchange format that is easy to read and write and is commonly used in RESTful APIs. In addition to JSON, RESTCONF also supports the Extensible Markup Language (XML) as a data-encoding method. You can specify which data-encoding method to use by including the appropriate media type in the "Content-Type" header of the RESTCONF request. For example, to use JSON encoding, you would include the media type "application/yang-data+json" in the "Content-Type" header. To use XML encoding, you would include the media type "application/yang-data+xml" in the "Content-Type" header.

RESTCONF—Uses structured data (XML or JSON) and YANG to provide a REST-like APIs. https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/prog/configuration/166/b_166_programmability_cg/restconf_prog_int.html#:~:text=RESTCONF%E2%80%94Uses%20structured%20data%20(XML%20or%20JSON)%20and%20YANG%20to%20provide%20a%20REST%2Dlike%20APIs

I'll go with C

.ust be C question is about restconfig not about restAPI... Some are confused between these with this question...

I just tested in the lab. If there is no Accept header, the output is in XML

The answer is JSON. It is in page 4 in the link https://www.cisco.com/c/en/us/td/docs/routers/csr1000/software/restapi/restapi/RESTAPIintro.pdf Cisco IOS XE REST API Request Methods The Cisco IOS XE REST API uses the HTTP request methods described in Table 1-2. Note All REST API requests and responses must be in JSON format. XML is not supported.

When you use RESTCONF talking about Cisco IOS-XE, the method data encoding must be XML, I think

XML is the default but supports also JSON

Default is XML I think

The IOS-XE documentation “Cisco IOS-XE REST API Managment Reference Guide” states : “All REST API requests and responses must be in JSON format. XML is not supported.”

Link referenced does not suggest that XML is the default encoding method. In fact, the first example shows JSON returned. RESTCONF on IOS XE supports both JSON and XML as data-encoding methods

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/prog/configuration/171/b_171_programmability_cg/restconf_protocol.html