Thanks for your response @nemobeer!
Unfortunately, I don't control the network or the switch. In fact, it's (sort of) my ISP's RJ45 jack in my home environment. More precise, they currently suffer an issue with a rogue DHCPd (200 customers affected) so i thought I'd try and make a temporary fix myself at home by somehow blocking that "bad" DHCPd on the net. DHCPd snooping on switch level is hence not an option. So this thing which was mentioned in the beginning of this ancient thread (about putting a block rule in Windows firewall) is not really feasible, correct?