Below is the steps to configure DHCP Discover message manually in raw streamblock.
1. Select the Frame size to Auto or Fixed 346 or above.
2. Unselect "Include Signature Field".
3. Navigate to Frame tab and Create new Frame and select as below.
4. Change Destination MAC to FF:FF:FF:FF:FF:FF, Source IP to 0.0.0.0 and Destination IP to 255.255.255.255
5. In DHCPClientMessage header make sure that the Client HW Addr. MAC and Client HW Address (in Client Id (Hardware)) are same as the Source MAC in EthernetII field. To Edit the field, rightclick and Edit Value.
We can also create the other DHCP message frames in the same way.
If the requirement is to generate DHCP malformed packet then change the Option Type (in End Of Options) from "FF" to say "10".