I was recently trying to PXE build a machine and was getting the error “PXE-E52: proxyDHCP offers were received. No DHCP offers were received”

I checked the SMSPXE.log on my SCCM 2012 R2 Distribution point and I could see that the machine MAC address was in the log, but it wasn’t getting an IP. I checked the DHCP Scope in my DHCP Console for this particular VLAN and noticed this icon  which meant “DHCP server alert. No addresses are available from server scopes because the maximum (100 percent) of the addresses allocated for use are currently leased. This represents a failure of the DHCP server on the network because it is not able to lease or service clients.” https://technet.microsoft.com/en-us/library/gg722802(v=ws.10).aspx

I increased the scope and now the machine could PXE boot successfully.