RESTCONF

In the previous lesson, you configured and managed a router using NETCONF.
You opened an SSH session on port 830, exchanged XML messages, and used the ncclient Python library.

But what if you could do the same thing with a simple HTTPS request?

Figure 1 – NETCONF vs RESTCONF

Same Data, Different Transport

RESTCONF (RFC 8040) provides a REST-like HTTP interface to access YANG-modeled data.
It uses the same YANG models as NETCONF. The data is the same. Only the transport changes.

Instead of SSH and XML, RESTCONF uses HTTPS and JSON.
Instead of a dedicated library like ncclient, you can use any HTTP client: Python requests, curl, or even a web browser.

Key Differences

RESTCONF is stateless. There is no session, no hello exchange, no capabilities negotiation.
Each request is independent and contains everything the device needs to process it.

Unlike NETCONF, RESTCONF has no candidate datastore, no lock, and no commit.
Every change is applied directly to the running datastore.

Table 1 – NETCONF vs RESTCONF

RESTCONF maps YANG data to HTTP. You interact with your device by sending HTTP requests to specific URLs.
Each URL points to a resource defined by a YANG model.

RESTCONF URI Structure

Every RESTCONF request targets a URI that follows a specific structure.
The URI tells the device exactly what resource you want to read or modify.

Figure 2 – RESTCONF URI structure

The HTTP method (GET, POST, PUT, PATCH, DELETE) defines the action. The URI identifies the resource:

• The protocol and host identify your device (e.g., https://192.168.1.1)

• /restconf/data is the API root that tells the device you want to access configuration or operational data

• The YANG resource path maps directly to the YANG model (module:container/resource/key=value)

HTTP Methods

RESTCONF uses standard HTTP methods. If you remember the CRUD operations from the REST API lesson, this will feel familiar.
Each method maps to a NETCONF operation:

Table 2 – HTTP methods mapped to NETCONF operations

What does that look like in practice?
If you want to read the description of GigabitEthernet1, you send a GET to /restconf/data/.../GigabitEthernet=1.
If you want to change it, you send a PATCH to the same URI with the new value in the JSON body.

Request and Response

When you send a GET request to your device, you include an Accept header to tell the device what format you want the response in.

Figure 3 – GET request

The header Accept: application/yang-data+json tells R1: "Send me the data in JSON format."
You could also use application/yang-data+xml to receive XML instead.