ping is working but tftp is not working on vexpress-a9 board for Image transfer

Question

Using Qemu for Network connection using bridge (TAP & UML utilities), when it is fetching through smc-911x0 device, it is successful

From u-boot prompt host is alive , but while transfer the Image , it is failing to do the same.

Observation: It is successful to transfer the data with SMC911x & is failing through ethernet3,0200000 device.

how to change the settings to fetch IP address through smc-911x0 device, instead of ethernet3,0200000. disabled wired-connection, still it is using ethernet 3,02000000 device

Environment is running on Virtual box & QEMU. board is vexpress-a9.

reference: https://learningfromyoublog.wordpress.com/2016/11/27/u-boot-arm-versatile-express-emulation-on-qemu-with-nfs-as-rootfs/

=> ping 10.0.2.15              

smc911x: detected LAN9118 controller

smc911x: phy initialized

smc911x: MAC 52:54:00:12:34:56

Using ethernet@3,02000000 device

smc911x: MAC 52:54:00:12:34:56

host 10.0.2.15 is alive

=> tftp 0x61000000 zImage

smc911x: detected LAN9118 controller

smc911x: phy initialized

smc911x: MAC 52:54:00:12:34:56

Using ethernet@3,02000000 device

TFTP from server 10.0.2.15; our IP address is 10.0.2.3

Filename 'zImage'.

Load address: 0x61000000

Loading: T T T T

It is keep failing here