Data Loss while Ping to Rx64M


I stuck in  one strange scenario. I used RX64M starter kit for porting of LWIP Stack to project. The porting is successful. But during continuous Ping some times the data is getting loss (Rx64M not responding). Out of 4 packet 2/3 packet is getting lost.

I have used PHY Channel 1 of Ethernet and generated Ethernet driver using code generated.

Can any one let me know How to resolve this issue?