X-IPLB-Request-Id
The HTTP X-IPLB-Request-Id unofficial response header carries a unique identifier assigned to each request by OVHcloud's IP Load Balancing service, used for tracing requests through OVH infrastructure.
Usage
OVHcloud's IP Load Balancing (IPLB) service distributes incoming traffic across backend servers within OVH's infrastructure. When a request passes through the IPLB layer, OVH assigns a unique identifier to the request and attaches the identifier to the response as X-IPLB-Request-Id.
The identifier enables end-to-end tracing of a request through OVH's network. When something goes wrong (a timeout, an unexpected error, or an anomalous response), the value from this header provides a reference point for OVH support engineers to locate the specific request in internal logs. This makes the header particularly useful when opening support tickets with OVHcloud, tying the reported issue to a concrete infrastructure event. The header appears alongside X-IPLB-Instance, identifying the specific load balancer node handling the request.
Values
Hexadecimal request identifier
The value is a hexadecimal string in HAProxy unique-id format, using colons and underscores as delimiters. The format string HAProxy's documentation gives as its example, which OVH's load balancer uses, encodes the fields in the open: the client IP and port, the frontend IP and port, a timestamp, a request counter, and the HAProxy process ID. That makes the value decodable rather than opaque, and worth knowing that the embedded frontend address can expose the OVH origin IP of a site otherwise sitting behind another CDN. The value is intended for internal log correlation rather than client-side interpretation.
Example
A response routed through OVH's load balancing layer includes a hexadecimal request identifier.
X-IPLB-Request-Id: 0003B5B7:07BF_0227E461:0050_67C14A5B_3A29E:0836
Both IPLB headers often appear together. The request ID identifies the transaction while the instance ID identifies which load balancer node handled the request.
X-IPLB-Request-Id: 0003B5B7:07BF_0227E461:0050_67C14A5B_3A29E:0836
X-IPLB-Instance: 52345