VXLAN adds 50 bytes to the original packet. The common denominator and recommended MTU value available on devices operating in a fabric role is 9100. Network should have a minimum starting MTU of at least 1550 bytes to support the fabric overlay. MTU values between 1550 and
9100 are supported along with MTU values larger than 9100 though there may be additional configuration and limitations based on the original packet size.
MTU 9100 is provisioned as part of LAN Automation. Devices in the same routing domain and Layer 2 domain should be configured with a consistent MTU size to support routing protocol adjacencies and packet forwarding without fragmentation.

Both Cisco Catalyst Center (formerly DNA Center) and vManage northbound APIs use RESTCONF, a standardized protocol for programmatic interaction with network devices.
The APIs primarily use JSON as the data exchange format, which is lightweight and widely used in RESTful APIs for communication between clients and servers.