The BFD (Bidirectional Forwarding Detection) is a protocol that detects link failures as part of the Cisco SD-WAN (Viptela) high availability solution, is enabled by default on all vEdge routers, and you cannot disable it.

JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained
way for securely transmitting information between parties as a JSON object. This information can
be verified and trusted because it is digitally signed. JWTs can be signed using a secret (with the
HMAC algorithm) or a public/private key pair using RSA or ECDSA.
JSON Web Tokens are composed of three parts, separated by a dot (.): Header, Payload,
Signature. Therefore, a JWT typically looks like the following:
xxxxx.yyyyy.zzzzz
The header typically consists of two parts: the type of the token, which is JWT, and the signing
algorithm being used, such as HMAC SHA256 or RSA.
The second part of the token is the payload, which contains the claims. Claims are statements
about an entity (typically, the user) and additional data.
To create the signature part you have to take the encoded header, the encoded payload, a secret,
the algorithm specified in the header, and sign that.

The Intent API is a Northbound REST API that exposes specific capabilities of the Cisco DNA Center platform. The Intent API provides policy-based abstraction of business intent, allowing focus on an outcome rather than struggling with individual mechanisms steps.