hey,

we are using SCCM 2012 R2 CU5 as Primary Stand Alone.
I am having the following infrastructure in one location:

DHCP:
OS: Server 2008 R2
IP: 192.168.0.11
Domain: Dom1.my
Scope Options for current scope:
-> Option 60 to PXEClient
-> Option 66 to SCCM Server IP

SCCM DP:
OS: Server 2012 R2
IP: 192.168.0.12
Domain: Dom2.my
Firewall: OFF
PXE setup via SCCM (all required roles and features available)

Client:
OS: No OS
IP: 192.168.0.101 (received during PXE)
Domain: No Domain

3rd Party OSD
OS: unknown
IP 192.168.0.13
Domain: Dom1.my

Because we are in migration process I have to keep the old 3rd Party OSD.
Only in the current DHCP scope clients should be able to boot from SCCM DP.
All other still have to boot from 3rd Party OSD.

When the client boots it receives an IP address an the SMSPXE.log on SCCM DP shows the following:

Client lookup reply: <ClientIDReply><Identification Unknown="0" ItemKey="16809345" ServerName=""><Machine><ClientID/><NetbiosName/></Machine></Identification></ClientIDReply>
	SMSPXE	30.07.2015 16:32:04	2948 (0x0B84)
00:50:56:8D:66:60, 22AD0D42-6F85-048F-2C8A-1F5D24C3F01E: device is in the database.	SMSPXE	30.07.2015 16:32:04	2948 (0x0B84)
Client boot action reply: <ClientIDReply><Identification Unknown="0" ItemKey="16809345" ServerName=""><Machine><ClientID>GUID:CFEF9A26-0E12-47ED-B6CC-50999AC94E8D</ClientID><NetbiosName/></Machine></Identification><PXEBootAction LastPXEAdvertisementID="" LastPXEAdvertisementTime="" OfferID="KN120152" OfferIDTime="5/12/2015 2:56:00 PM" PkgID="KN1004D5" PackageVersion="" PackagePath="http://SCCM-DP.Dom2.my/SMS_DP_SMSPKG$/KN100415" BootImageID="KN100415" Mandatory="0"/></ClientIDReply>
	SMSPXE	30.07.2015 16:32:04	2948 (0x0B84)
00:50:56:8D:66:60, 22AD0D42-6F85-048F-2C8A-1F5D24C3F01E: found optional advertisement KN120152	SMSPXE	30.07.2015 16:32:04	2948 (0x0B84)
Client boot action reply: <ClientIDReply><Identification Unknown="0" ItemKey="16809345" ServerName=""><Machine><ClientID>GUID:CFEF9A26-0E12-47ED-B6CC-50999AC94E8D</ClientID><NetbiosName/></Machine></Identification><PXEBootAction LastPXEAdvertisementID="" LastPXEAdvertisementTime="" OfferID="KN120152" OfferIDTime="5/12/2015 2:56:00 PM" PkgID="KN1004D5" PackageVersion="" PackagePath="http://SCCM-DP.Dom2.my/SMS_DP_SMSPKG$/KN100415" BootImageID="KN100415" Mandatory="0"/></ClientIDReply>
	SMSPXE	30.07.2015 16:32:08	2948 (0x0B84)
00:50:56:8D:66:60, 22AD0D42-6F85-048F-2C8A-1F5D24C3F01E: found optional advertisement KN120152	SMSPXE	30.07.2015 16:32:08	2948 (0x0B84)
Client boot action reply: <ClientIDReply><Identification Unknown="0" ItemKey="16809345" ServerName=""><Machine><ClientID>GUID:CFEF9A26-0E12-47ED-B6CC-50999AC94E8D</ClientID><NetbiosName/></Machine></Identification><PXEBootAction LastPXEAdvertisementID="" LastPXEAdvertisementTime="" OfferID="KN120152" OfferIDTime="5/12/2015 2:56:00 PM" PkgID="KN1004D5" PackageVersion="" PackagePath="http://SCCM-DP.Dom2.my/SMS_DP_SMSPKG$/KN100415" BootImageID="KN100415" Mandatory="0"/></ClientIDReply>
	SMSPXE	30.07.2015 16:32:16	2948 (0x0B84)
00:50:56:8D:66:60, 22AD0D42-6F85-048F-2C8A-1F5D24C3F01E: found optional advertisement KN120152	SMSPXE	30.07.2015 16:32:16	2948 (0x0B84)
Client boot action reply: <ClientIDReply><Identification Unknown="0" ItemKey="16809345" ServerName=""><Machine><ClientID>GUID:CFEF9A26-0E12-47ED-B6CC-50999AC94E8D</ClientID><NetbiosName/></Machine></Identification><PXEBootAction LastPXEAdvertisementID="" LastPXEAdvertisementTime="" OfferID="KN120152" OfferIDTime="5/12/2015 2:56:00 PM" PkgID="KN1004D5" PackageVersion="" PackagePath="http://SCCM-DP.Dom2.my/SMS_DP_SMSPKG$/KN100415" BootImageID="KN100415" Mandatory="0"/></ClientIDReply>
	SMSPXE	30.07.2015 16:32:33	2948 (0x0B84)
00:50:56:8D:66:60, 22AD0D42-6F85-048F-2C8A-1F5D24C3F01E: found optional advertisement KN120152	SMSPXE	30.07.2015 16:32:33	2948 (0x0B84)

After this the client ends with the error message:
PXE-E55: ProxyDHCP service did not reply to request on port 4011

__________________________________________________________
What I already tried is the following:
--Remove and add PXE from the DP
--Remove all scope options from DHCP
--Set scope option 60; 66; 67 one after another and check for every the solution
  (Without any I receive a different message which I think comes from the 3rd Party OSD)
--Try different clients

DHCP snooping? (http://www.mssccmfaq.de/2011/06/28/no-response-from-windows-deployment-services-server/)
Have you already tried using option 66/67 only. I've never seen that 60 was required. Plus it's always better to use IPhelpers instead of dhcp options. You might have to use Netmon/Wireshark to get an idea what's going on.