dhcp is unable to resolve:

in U-boot> dhcp
Retry count exceeded; starting again
BOOTP broadcast 1
DHCP client bound to address 172.23.16.143
TFTP from server 10.20.4.10; our IP address is 172.23.16.143; sending through gateway 172.23.16.1
Filename 'pxelinux.0'.
Load address: 0x400000
Loading: T T T T T T T T T T

I have used: setenv serverip <ip> then saveenv, printenv confirms it is set, but yet the server ip listed above persists.

I tried using setenv to put them on the same subnet, again, the change doesn't persist when I run dhcp.

I have 2 network setups with this board, they both fail in the same way. (Putty is used in both cases)
Here are the network setups in both cases:
1. The board's ethernet cable is hooked to the same router that my windows desktop is connected to. ( I would like the board to be able to grab flash images from a linux box- or a flash card)

2. The board's ethernet cable is directly connected to a linux box

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I can't see where it is gettting the serverip or the IP address. I haven't set it and haven't yet found where it is being set. I have grep -r all over, no where do I see the serverip it is picking up.

Suggestions?

It is probably obvious that I am new to embedded linux.