Regarding to my last blog post about the separation of clients and servers in different VLANs (Look here) and specially the first comment: I no longer wanted to use the DHCP Options for PXE Boot.

But first let me explain:
My problem was, I thought that I only could use DHCP Options, because I could not configure IP-Helpers on my pfSense Firewall. This was why my last Blogpost was based on, and the first commenter Phil2Pint gave a very interesting Link about how to deliver the correct Boot Image to the UEFI or BIOS client which wants to boot from PXE:
http://2pintsoftware.com/download/using-dhcp-to-control-wds-pxe-boots-for-bios-efi-clients/
But I didn’t want to implement this solution, to much effort for me. In my opinion it should be possible to achieve the same solution like cisco have with their ip helper functionality. But I could not find directly any hints, how to configure iphelper on the pfSense, it may also was the lack of understanding the ip helper, because I never used a cisco before. But in all forums I have found with the Error:
Windows Deployment Services encountered an error 0x102
was, they configured the ip helper on their cisco device.

I already used the DHCP relay option from the pfSense, but it took a while, until I recognize, that I only have to add the WDS Server to the DHCP Relay option like Follows:
192.168.1.161,192.168.1.172

Afterwards, everything was working like expected, without any dhcp boot options.