Checklist to ensure telemetry network requirements are met
Expected to see specific telemetry data, but that data is missing from the controller API.
Review the following checklist to ensure telemetry network requirements are met:
- Ensure that User Datagram Protocol (UDP) traffic is:
- Allowed from the security gateway to the controller
- Allowed between services in the controller
- Ensure that Internet Control Message Protocol (ICMP) messages of type 3 (Destination Unreachable) are:
- Allowed to propagate from the controller to the Intel® Smart Edge Node
- Allowed between services in the controller
The controller's telemetry service utilizes a UDP-based protocol to receive status and event information (stats) from the Intel Smart Edge Node, applications, and various services in the controller. This UDP protocol does not provide a mechanism to send back acknowledgements of successfully received stats. Due to this limitation, it is not possible to know at the UDP layer when a connection to a service is no longer working.
However, the operating system will send back ICMP messages indicating the network is not reachable when a service is not listening on a specific UDP port. This ICMP information allows the service sending stats to know when a problem has occurred and how to appropriately act, for example, connect to a different statstore instance, or log an error.