let me share with you how to add Client static route using DHCP (Option 121)
in some cased we need to do that to avoid some network issues like TMG
A non-SYN packet was dropped because it was sent by a source that does not have an established connection with the Forefront TMG computer
Open DHCP console expand your IP Scope.
Right click on Scope Options and go to Configure Options
Select Scope option 121 Classless Static Routes