dhcp and iptables

toombs · 02-08-2007, 10:21 AM

Is there an iptables rule that would reject all incoming packets from hosts which haven't received their current ip address from a dhcp daemon running on the same server?

acid_kewpie · 02-08-2007, 11:26 AM

not in itself, but i'm sure you could made a script which watches the leases and adds and removes iptables commands when a lease is taken out. there is no such thing as a dhcp lease being "switched off" or anythign though, so you'd want short lease times i guess, and remove iptables entries when a lease expires.

toombs · 02-08-2007, 02:35 PM

ok thanks. It would've been nice if I didn't need a script but that's fine. I'll see what I can do.

acid_kewpie · 02-08-2007, 03:12 PM

well scripts don't have to be complicated. often the work involved to integrate a normal solution can be more than a self made script...

i googled for a relevent subject, and actually ended up back here... http://www.linuxquestions.org/questi...d.php?t=266151 looks useful potentially.

toombs · 02-08-2007, 04:35 PM

yeah that's exactly what I'm looking for but for a different purpose. I am setting up an nfs server and I only want trusted hosts with known mac addresses to be able to connect. While I was doing this research, though, I thought of a better way. Since the trusted mac's are static, I don't need dhcp to tell iptables which mac addresses are ok. I can just add static rules. It's an interesting concept though, and it would be a very useful feature.

acid_kewpie · 02-09-2007, 02:58 AM

oh well in that case, yes a static database would be much more preferable. potentially you'd be able to use the dhcpd.conf as that database so as not to have to duplicate the work, but yeah that's right on the money if it's only a local subnet.

toombs · 02-09-2007, 05:14 PM

I have more experience than you think. The Newbie tag is a little misleading as I just switched nicknames

acid_kewpie · 02-10-2007, 02:33 AM

erm. ok i'm very happy for you.

acid_kewpie · 02-10-2007, 02:33 AM

erm. ok i'm very happy for you.