YANG Suite is HTML5-based tooling that is available for working with the YANG-based programmable interfaces on Cisco IOS XE, XR, and Nexus network operating systems. It has plug-ins that allow for interacting with the programmable interfaces and supports downloading YANG files directly from network devices. In this tutorial, we will explore using RESTCONF and gRPC to interact with the APIs in a switch.

What You’ll Learn

• Use YANG Suite to make a RESTCONF call to get a loopback interface data
• Use YANG Suite to stream gRPC telemetry and configure the switch to send the telemetry

What You’ll Need

• YANG Suite installed, locally or in a container
• A network device running NETCONF, such as a Cisco Catalyst 9300 switch or Cloud Services Router (CSR) 1000V
• Alternatively, if you have access to dCloud, you can use it here, lab name “Cisco Catalyst 9000 IOS XE Programmability & Automation Lab v1”.

RESTCONF is a standard protocol using HTTP to access APIs defined in YANG. The YANG Suite application helps visualize this process, but you can interact with the API with something like a Python script as well. There is another tutorial covering using RESTCONF with Python requests.

In this step you will make an API call to get the interface description using RESTCONF and YANG Suite.

1. Protocol: “RESTCONF”
2. Select a YANG Set: “c9300-default-yangset”
3. Select a device: “C9300”
4. Select YANG modules: “Cisco-IOS-XE-native”
5. Select depth limit: “2”
6. Select “Load Module(s)”

1. Once the tree loads, close the popup that says “Tree generated, please select node(s) to generate API(s)”
2. Expand the tree by selecting the arrow next to “Cisco-IOS-XE-native”

1. Search for “interface” in the expanded tree. (note: select CONTROL + F to find “interface” on the page)
2. Expand “interface” and search for “Loopback" (note: select CONTROL + F to find “Loopback” on the page)

1. Click the blue “Generate API(s)” button. (note: it may take a few moments to load the APIs)
2. Close the popup that says “API(s) are generated”

1. Click the blue “Show API(s)” button
2. Select the link next to the “GET” operation corresponding to the API call “/data/Cisco-IOS-XE-native:native/interface/Loopback”
3. Click the “Try it out” button

1. Click the “Execute” button to send the RESTCONF payload and view the reply, including the Loopback Netmask

gRPC is an open-source RPC framework that is used for streaming telemetry (operational data) from infrastructure devices. Think of a more modern SNMP, but with better APIs and much faster.

In this task you will use YANG Suite to set up a gRPC telemetry subscription. The network device needs some configuration to start streaming the telemetry, and the configuration is provided below.

gRPC subscription

1. In YANG Suite,
   1. Protocol: “gRPC telemetry”
   2. Listen at IP address: “0.0.0.0”
   3. Listen at port: “58500”
   4. Click the “Start receiver” button

1. On the switch, configure the subscription by copy/pasting the configs:

   conf t
   telemetry ietf subscription 2011
   encoding encode-kvgpb
   filter xpath /ios:native
   stream yang-push
   update-policy periodic 6000
   receiver-type protocol
   receiver name yangsuite
   
   telemetry receiver protocol yangsuite
   host name yangsuite-telemetry.cisco.com 58500
   protocol grpc-tcp
   

1. Back in YANG Suite, check the telemetry data that should appear at regular intervals on the “gRPC telemetry” screen
2. When the telemetry data begins to flow from the C9300 into YANG Suite, several lines of data will be displayed. Included in this is the timestamp, subscription ID, node, path, name, and value fields.

Learn More

• YANG Suite GitHub repository to install locally or in a container
• ENAUTO Certification
• YANG Basics tutorial
• RESTCONF with Python requests tutorial