blocking DHCP requests

jjfate · 06-20-2003, 12:30 PM

Is it possible to use IPTables to block a specific protocol like DHCP? Could anyone point me in the direction of a good tutorial?

manthram · 06-20-2003, 12:42 PM

yeah you can do that and dvery easily. just tell it to drop all the packets which have a source and destination ports of 67 and 68.

IPTABLES -A INPUT -i interface -dport 67:68 -sport 67:68 -j DROP

you can goto netfilter and check out their documentation

jjfate · 06-20-2003, 01:01 PM

Perfect, thank you very much!

jjfate · 06-20-2003, 01:05 PM

just one more thing I thought of, I have eth0 and eth1;

I would like to block dhcp requests coming only from eth1, does that fit into the syntax here as well?

jjfate · 06-20-2003, 01:49 PM

oops nevermind....i saw the light!