Microsoft actively discourages using the SIO_LOOPBACK_FAST_PATH socket option:
Important The SIO_LOOPBACK_FAST_PATH is deprecated and is not recommended to be used in your code.
As such, the TcpLoopbackFastPath configuration option and the use of SIO_LOOPBACK_FAST_PATH should be removed from Firebird 5.0, and disabled by default in next versions of Firebird 3.0 and 4.0.
Microsoft actively discourages using the
SIO_LOOPBACK_FAST_PATHsocket option:As such, the
TcpLoopbackFastPathconfiguration option and the use ofSIO_LOOPBACK_FAST_PATHshould be removed from Firebird 5.0, and disabled by default in next versions of Firebird 3.0 and 4.0.