Tolun ARDAHANLI wrote: > WAN(this ip comes from behind of swicth. the switch is behind of > firewall and firewall is behind of router): > WAN side Server ip: 192.168.10.13 <http://10.10.1.223/> > gateway address of Server:192.168.10.1 <http://10.10.1.111/> if you already have a router/firewall and a switch on the internet side, what is this CentOS system doing in the middle? why not just hook everything up to the same switch and let them all run with IP's from your existing router? this is what you're describing... internet -> router -> firewall -> switch----192.168.1.0/24 ---> centos server -----192.168.10.0/24----> LAN systems why not.... internet -> router -> firewall -> switch ----192.168.1.0/24---> LAN including centos server ?