You could set up DHCP with a smaller set of addresses, for example x.x.x.100- x.x.x.110 if you only have 10 workstations. Then drop everything accessing the Internet except for those source addresses. If you want to go further than that, like stop someone from getting their information from DHCP and then statically defining it and keeping that address, it gets a little more involved. Maybe reducing the lease time and scripting to check that all the stations in the DHCP range are also in the list of DHCP clients on the server would help. Matt Grogan ________________________________________ From: netfilter-admin@xxxxxxxxxxxxxxxxxxx [mailto:netfilter-admin@xxxxxxxxxxxxxxxxxxx] On Behalf Of PiSiC... Sent: Tuesday, June 17, 2003 4:31 AM To: netfilter@xxxxxxxxxxxxxxxxxxx Hi all, ? I want to ask you something... You know a possibility to drop outgoing traffic of clients who define their address staticaly instead of using my DHCP server ? I also want to allow outgoing access to those who have their IP address given by my DHCP server. ? Thank you in advance, ???????????????????????????????????????? Danila Octavian