Hi, Durga,
From the phenomena, it seems the issue is a hardware issue, your power-on Reset circuit has problem instead of ethernet code.
First of all, pls develop a simple code to toggle a led, after download it to flash, check if the led flashs or not. If the led can not toggle, sure it is power-on Reset problem.
If it is power-on Reset problem, do you use RC circuit or dedicated Reset circuit? If you use RC circuit for the Reset pin, how about using the R=4.7K ohm and C=0.1uF? I check some of K64 tower board, it uses the specs.
Hope it can help you
BR
Xiangjun Rong