TCP urgent data processing is a rarely-used feature that is inconsistently implemented on various operating systems. In Onload 201811 a new EF_TCP_URG_MODE environment variable has been added, that can be used to ignore this feature.
Important: If urgent data is received when
Onload is configured to ignore urgent data
processing, it is intermingled with the main data stream. If an application relies on
such packets forming a separate data stream, this results in the data it receives being
corrupted.