In addition the script also reads the sysctl options in /etc/sysctl.conf, this is where you can configure the system as a router (allow IP forwarding in the kernel). For example the line:net.ipv4.ip_forward = 1will enable ip forwarding and the file /proc/sys/net/ipv4/ip_forward will contain a one.The network script is started with the following command/etc/rc.d/init.d/network restart?. Renewing a DHCP leaseThe following tools can query the DHCP server for a new IP:pumpdhcpclient A client daemon exists called dhcpcd (do not confuse this with the DHCP server daemon dhcpd)RoutingA noticeable difference when using ifup is the systems routing table. This is because either the /etc/sysconfig/network file is read, where a default gateway is stored, or the DHCP server has sent this information together with the IP number. The routing tables are configured, checked and changed with the /sbin/route tool.Routing examples:Add a static route to the network 10.0.0.0 through the device eth1 and use 192.168.1.108 as the gateway for that network:/sbin/route add -net 10.0.0.0 gw 192.168.1.108 dev eth1Add a default gateway: