@george1421 i changed to ExternalNet. but nothing has been changed. I found something in the community of ventoy which could help me.
maybe you can tell me what the post means. because am not good enough in pxe.
https://forums.ventoy.net/showthread.php?tid=2743
someone posted:
I managed to chainload from my main iPXE to iVentoy, basically you need to do following things:
1. In your main iPXE boot.ipxe file, set user-class to a specific value, such as MyCustomClass
2. In your dhcp server, match this user-class and send next-server as your iVentoy IP
3. In your main iPXE boot.ipxe, run 'dhcp' command, after 'set user-class MyCustomClass' command, then 'chain tftp://${next-server}/iventoy_loader_16000'
Done