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I blocked a MAC address of a client on my DHCP Server running on Ubuntu 12.10 using

iptables -A INPUT -m mac --mac-source -j DROP

But I am still getting DHCP requests from the client and the client is getting the IP address from my DHCP server too. I think the command does not work for broadcast messages. Is there any other technique to do it? I do not have access to the DHCP Server code.

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up vote 1 down vote accepted

iptables is the IPv4 implementation of iptables. For the IPv6 version, you need to use ip6tables

Using the same command, but with ip6tables should make that work.

Remember to back up your rules, though, for both iptables and ip6tables, with iptables-save > /some/path and ip6tables-save > /some/path, or use iptables-persistent and then save the rules, so that you can recall the rules if the system restarts or something!

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