New Installation of WDM 5.7.2

Hallo,

after we maid a new Installation of our WDM 5.7.2. Workstation, we have some Problems by imaging WES7 Client in one of our Subnet.

We have two Subnet with own DHCP-Servers. The WDM is in SUB2. In Sub2 all WDM Funktion work perfekt inkl. WES7 Imaging.

In SUB1 everithing works, but we cannot push or pull an WES7 Image from there. The two Subnet are connetced by Router from our Provider.

On DCHP Server SUB1 we set DHCP to :

DNS SRV is also set. The WES Client in SUB1 starting the Imaging-Prozess until stating Merlin. Then i get the following Error :

What can be the Problem ? I Need some help.