Initialising the TCP/IP Stack
Part of the FreeRTOS+TCP Networking Tutorial

/* The MAC address array is not declared const as the MAC address will
normally be read from an EEPROM and not hard coded (in real deployed
applications).*/
static uint8_t ucMACAddress[ 6 ] = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55 };

/* Define the network addressing.  These parameters will be used if either
ipconfigUDE_DHCP is 0 or if ipconfigUSE_DHCP is 1 but DHCP auto configuration
failed. */
static const uint8_t ucIPAddress[ 4 ] = { 10, 10, 10, 200 };
static const uint8_t ucNetMask[ 4 ] = { 255, 0, 0, 0 };
static const uint8_t ucGatewayAddress[ 4 ] = { 10, 10, 10, 1 };

/* The following is the address of an OpenDNS server. */
static const uint8_t ucDNSServerAddress[ 4 ] = { 208, 67, 222, 222 };

int main( void )
{
    /* Initialise the RTOS's TCP/IP stack.  The tasks that use the network
    are created in the vApplicationIPNetworkEventHook() hook function
    below.  The hook function is called when the network connects. */
    FreeRTOS_IPInit( ucIPAddress,
                     ucNetMask,
                     ucGatewayAddress,
                     ucDNSServerAddress,
                     ucMACAddress );

    /*
     * Other RTOS tasks can be created here.
     */

    /* Start the RTOS scheduler. */
    vTaskStartScheduler();

    /* If all is well, the scheduler will now be running, and the following
    line will never be reached.  If the following line does execute, then
    there was insufficient FreeRTOS heap memory available for the idle and/or
    timer tasks to be created. */
    for( ;; );
}
						

void vApplicationIPNetworkEventHook( eIPCallbackEvent_t eNetworkEvent )
{
static BaseType_t xTasksAlreadyCreated = pdFALSE;

    /* Both eNetworkUp and eNetworkDown events can be processed here. */
    if( eNetworkEvent == eNetworkUp )
    {
        /* Create the tasks that use the TCP/IP stack if they have not already
        been created. */
        if( xTasksAlreadyCreated == pdFALSE )
        {
            /*
             * For convenience, tasks that use FreeRTOS+TCP can be created here
             * to ensure they are not created before the network is usable.
             */

            xTasksAlreadyCreated = pdTRUE;
        }
    }
}