DHCPD

Hello list, Installed server with SuSE7.2, DHCPD with in dhcpd.conf a nameserver on the internet (ISP). Although firewall is not configured yet, and forwarding is still 0 (cat /proc/sys/net/ipv4/ip_forward), the system is building a connection to the ISP with every request from a client on the network (eth0). System: eth0 (DHCPD is listening here) and ippp0 for Internet. How can I avoid the machine building a connect to ISP for every dhcp request?? TIA Leen