I'm using P2041RDB-PC and this target is connected to Linux host PC (Ubuntu 16.04 LTS). I'm able to ping host PC from u-boot but vice versa cannot be done. When I'm trying to ping p2041rdb from host pc, it is unsuccessful. Because of this problem, tftboot command (download binary file from host pc )cannot be used.
Ping from U-Boot to a host should work. Ping from a host to U-Boot should not.
U-Boot uses a polling interface for networking - if you have not run a command, it will not respond to any packet.