hi all,

i want to deny any client to obtain an ip address from the dhcp server.

but what can i do when The user is a new in the network and he hasn’t ip address

thanks in advance

what criteria are you after? you can easily manage a list of known MAC addresses with dhcpd (http://www.daemon-systems.org/man/dhcpd.conf.5.html - check the exmaples for references to "hardware ethernet xx:xx:xx:xx:xx:xx", a possibly nicer solution can be to use a special dhcp user class, which acts *something* like a password, so the users device is built to a standard which then adds a class attribute to it's request, so it asks for "an ip address for class companyowneddevice" rather than just "an ip address"... if this doesn't cover what you want, then you need to dscribe your scenario better...

sorry i mean in the iptables rules i want to deny any new client to get ip from the dhcp server
as i know i will deny any traffic with source ip 0.0.0.0/0.0.0.0 and source port 68 go to destination ip 255.255.255.255 with destination port 67 in the chain FORWARD of the ethx

is it right or not ?

thanks in advance

iptables?? where did that come into the equation?? i can't see why you think iptables will be at all relevant here. how about you explain exactly what you want the user experience to be in terms of a number of use cases... probably the best way forward.