linux – Is it possible to block dhcp traffic using iptables?

I have two devices with embedded Linux. One of them (machine A) have two network interfaces: eth that is used to connect machines together and wlan interface to connect to router via WiFi. The second machine (B) has only one eth interface. My goal is to enable access to WiFi networks on the machine B. I used some iptables rules to filter packets from machine A to machine B and it works. To make this rules work I needed to get IP address from the dhcp server on machine A and clone this address on the machine B. Now, I need to block dhcp traffic on the first machine so that it does not reach the second machine. I was looking for some iptables rules to do it but I found that it is impossible with iptables. Is there any other way to block that traffic?

Thank you in advanced for any help.