I currently have 3 machines: CentOS (router) eth1 - 18.0.168.1 eth2 - 145.165.34.1 Windows Server 2008 (server) 18.0.168.2 DHCP scope - 145.165.34.10 - 145.165.34.20 Windows 7 (client) Supposed to use DHCP I can't get my Windows 7 client to get an address from the Windows Server 2008 DHCP server. Every network interface can ping each other (ex. 18.0.168.2 can ping 18.0.168.1 & 145.165.34.1 and the other way around). My Linux machine acting as the router has default IP tables. Other than this command which may or may not be right: iptables -I INPUT -p udp -d 18.0.168.2 --dport 67:68 -j ACCEPT I have also tried it after I flushed the IP tables. I was looking at the dhcrelay command but it seems CentOS doesn't have it and I am not even sure how to use it.