How to detect Ethernet cable connection before start a Network Interface?

[Altera_Forum]

Hello, 

  I am using Altera Cyclone-V and uC/OS-II OS & TCP/IP package building a Network Interface in this way:   

1. Call Net_Init();  
2. Call NetIF_Add();  
3. Call NetIF_Start();  
4. Call NetIPv4_CfgAddrAdd(); 

  Everything works fine except if I by accident forgot to plug in the Ethernet cable. If the cable is missing, Step C NetIF_Start() will return “NET_PHY_ERR_TIMEOUT_AUTO_NET” error. This error is not recoverable even with the cable plugging back to the device. I will have to reboot the device.  Is there any way I can check the cable connection before Step C? I tried functions like NetIF_LinkStateGet(), NetIF_IO_Ctrl(), but they only report the Link status after the interface is established. BTW, the HW is done and I can’t physically check the Ethernet port status.  Another option is when function NetIF_Start() returns an error due to the missing of the cable, what is a correct procedure to re-initialize the Network interface and wait for the cable connection.  Thanks,  Chad 

[Altera_Forum]

I also met this issues if I plug out the cable. Immediately I plug in cable and can't PING the board.