>> $ sudo iptables-save | grep 67 >> -A udpincoming_packets -p udp -m udp --sport 67:68 --dport 67:68 -j ACCEPT > > I'm not entirely fluent in iptables syntax, but to me this sounds like > "accept packets with source port 67/68 AND dest port 67/68". I > believe that you need "accept source port 67/68 OR dest port 67/68".
I'm pretty sure the only time any other ports would be used for dhcp is with a relay agent. dhcp clients should send from the well-known bootp port to the well-known bootp port.
