PC1 can do ping PC2 without any download bitstream

[kodarkI]

Hi all,
I needs your help. Could I have questions?
I have problem with my netfpga 1g cml.
When I tested connecting that my PC1 can do ping PC2 through interface nf0,nf1(or nf2,3) of netfpga 1g cml
without any download bitstream.
This is a normal doing for netfpga 1g cml or abnormal.

If it is not normal
How can I fix ? Or how can I solve this problem ?

Or it means there are somethings changing in the board program. How can I reset to clear the board program to factory settings?

When I tried to download bitstream into Netfpga Then it showed Ethernet controller :Xilinx Corporation Device 4244.
This is also possible / normal ?