Error 3c092003 http chain

[ryanex]

Good day,
I try my best to explain in English.

Currently I ipxe virtuale installed on a debian server.
This all works well. Systems via tftp works well, and can I install linux.


When I follow the following guide http://ipxe.org/howto/winpe

I make winpe to, copy it to a http folder.
I can be on the http location using the two network cards connect via a web browser.

The local 192.168.20.x and the intranet between the virtual network PCs
http://192.168.10.170/winpe/ (local network)
and
http://192.168.20.1/winpe/ (virtual internal network brigde)

I enter the following commands in
(control + B)
DHCP
chain http://192.168.20.1/winpe/boot.ipxe

Then I get the error:
Could not start download: opeation not supported (http://ipxe.org/3c092003)

This error on the site, I can not deduce what I'm doing wrong.
Can someone help me?