The official graphical configuration tool is system-config-network (Menu System Settings - Network), from here is possible to define the IP parameters for all the interfaces found on the system (tab Devices, modifies the /etc/sysconfig/network-scripts/ifcfg-interface and /etc/sysconfig/networking/devices/ifcfg-interface files), the IP of the DNS servers (tab DNS, modifies /etc/resolv.conf), the static host IP assignement (tab Hosts, modifies /etc/hosts).
Tu comando es routeDe todas formas, como bien dice su -, la puerta de enlace la puedes modificar en /etc/sysconfig/network-scripts/ifcfg-interface y /etc/sysconfig/networking/devices/ifcfg-interface.
MODE=Master