rl_net for UDP implementation on lpc4357, KEIL5

Dear Team,

I am implementing UDP protocol on HITEX dev board (lpc4357) using rl_net library with KEILv5.36 compiler 5. I have written the code as per the documentation found on LINK.

Test Setup: HITEX board is connected to windows 10 laptop using ethernet cable. Laptop is running Hercules utility to test UDP.

HITEx board IP: 192.168.0.100, port: 2000

laptop ip: 192.168.0.10             , port: 2005

Problem: 1. Ethernet jack LEDs (orange & green) are glowing on both sides, but i am not able to ping hitex board.

2. While debugging I get successful response for functions but data is not seen on hercules terminal.

3. I am using network debug facility in keil5 and receiving error as "ARP-ERR: Cache_find ETH0 Unresolved MAC".

Does the (3) is causing the problem.

I am attaching my UDP send task below for reference.

// Notify the user application about UDP socket events.
uint32_t udp_cb_func (int32_t socket, const NET_ADDR *addr, const uint8_t *buf, uint32_t len) 
	{ 
  // Data received
  if ((buf[0] == 0x01) && (len == 2)) {
    // Switch LEDs on and off
    //LED_out (buf[1]);
		//do something
  }
  return (0);
}
 
// Send UDP data to destination client.
void send_udp_data (uint8_t *str) 
{ 
  if (udp_sock >= 0 && !udp_open_status) {
    // IPv4 address: 192.168.0.10
    NET_ADDR addr = { NET_ADDR_IP4, 2005, 192, 168, 0, 10 };
    // IPv6 address: [fe80::1c30:6cff:fea2:455e]
    //  NET_ADDR addr = { NET_ADDR_IP6, 2000,
    //                    0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    //                    0x1c, 0x30, 0x6c, 0xff, 0xfe, 0xa2, 0x45, 0x5e };
    uint8_t *sendbuf;
 
    sendbuf = netUDP_GetBuffer (strlen((char *)str));
		if(sendbuf)
		{
			strcpy((char *)sendbuf, (char *)str);
			//sendbuf[0] = 0x01;
			//sendbuf[1] = 0xAA;
		}
		else
			u0TxString(getBufferErr);
 
    udp_send_status = netUDP_Send (udp_sock, &addr, sendbuf, strlen((char *)sendbuf));
  }
}

void udp_thread (void *argument) 
{
	//udp socket testing
  net_init_status = netInitialize();
	osDelay(6000);
	
	// Initialize UDP socket and open port 2000
  udp_sock = netUDP_GetSocket (udp_cb_func);
  if (udp_sock >= 0) {
    udp_open_status = netUDP_Open (udp_sock, 2000);
		u0TxString(ethConnectSuccess);
  }
	else
		u0TxString(getSocketErr);
	
	while(1)
	{
		send_udp_data((uint8_t *)ethConnectSuccess);
		osDelay(500);
	}
}

Hercules window: 

KEIL network debug window: