To override the name of the default router that is provided by the network configuration server, do the following:
Creating /etc/defaultrouter and leaving this file empty causes one of the two dynamic routing protocols to run: ICMP Router Discovery Protocol (RDISC), or Routing Information Protocol (RIP). The system first runs the program in.rdisc, which looks for routers that are running the router discovery protocol. If in.rdisc finds one such router, in.rdisc continues to run and monitors the routers that are running the RDISC protocol.
If the system discovers that routers are not responding to the RDISC protocol, the system uses RIP and runs the in.routed daemon to monitor the routers.