BFDD_WRITE_ERROR message is reported into the system message file anytime the Bidirectional Forwarding Detection daemon (BFDD) is shut down abruptly during a session. This is any informational level message.
The problem related to this syslog message is described in the following sections:
A pipe is a unidirectional, stream communication abstraction. One process writes to the “write end” of the pipe, and a second process reads from the “read end” of the pipe. When a BFDD session is started, information is sent across the pipe. One end writes to the pipe and the other reads from the pipe. If the BFDD Daemon is interrupted, the following informational log message is reported:
BFDD_WRITE_ERROR: Write error on upstream pipe: premature EOF (connection closed)
The Bidirectional Forwarding Detection process (bfdd) could not write the message available on the indicated type of pipe.
The messages are informational and are triggered any time the BFD process is abruptly shut down, such as a hardware reset, RDP crash, or restart of the BFD process.
This message will appear in the logs depending on the logging level. The severity level of this message is info. Therefore, if you have syslog set to log informational messages, these messages will appear in the log.
These messages by themselves are harmless. They are a notification that the BFDD was shut down abruptly. The cause for the notification will be in the event preceding such a protocol or interface flap, RDP failure, an interface brought down, or anything that will cause an interruption in the BFDD session. Depending on the event, there may be a cause to troubleshoot further or simply ignore the message as expected behavior.
You can change logging level under syslog to prevent these messages from appearing.