How can I use Ethernet to send something value??

In the enet_lwip.c example, I check the IP address of the LCDK in the TeraTerm. 

And I check the mac address and IP address of the LCDK in the Wireshark.

 But, I don't know why IP address and Mac address appear in the wireshark.  Why??

I would like to proceed with the use of other Ethernet,  let me know if you have any other examples or manuals. Please....

I want to send another value using Ethernet. What should I do??

I use the C6748 Development Kit(LCDK), TMS320C6748. And Compiler is CCS V5_5.