Windows deployment services

I prepared my servers with AC,DNS,DHCP,WDC . I want to install windows 7 By WDC over my network , everything was fine until i reach this stage of my job.

when I restart my pc (host in the network ) and force it to download from network it could not take ip from the DHCP.

here some explanation about my network

1-in the middle of my network i have firewall from this firewall one port exit to servers cloud and the second port exit to a network with ip ex: 192.168.5.x and third port exit to network with ip ex:172.16.4.x and the last port exit to router which give the network with these ips ex : 192.168.55.x 192.168.77.x 192.168.66.x

2-each network in different site

3-we user generally static ip at this point

4- if i run the pc it take ip from the dhcp normally