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LibrariesinsideAPI reference

Updated Jul 2025

FreeRTOS_SetNetmask()

[FreeRTOS-Plus-TCP API Reference]

FreeRTOS_IP.h

1void FreeRTOS_SetNetmask( uint32_t ulNetmask );

This function can be used to update the IPv4 subnet mask used by the FreeRTOS-Plus-TCP device after the TCP stack has already been initialized with a call to FreeRTOS_IPInit().

Parameters:

  • ulNetmask

    The 32-bit IPv4 netmask, in network endian order, which the device should use. FreeRTOS_htonl
    can be used to get the network endian representation of the 32-bit IP netmask.

Caution:

This function is not thread safe and should be used with the 

taskENTER_CRITICAL/taskEXIT_CRITICAL
pair. A call to this function should be made only when there is no active connection (either UDP or TCP), or else that connection might be severed.

Example usage:

See the FreeRTOS_SetIPAddress page for an example.