The /etc/defaultrouter file specifies
a IPv4 host's default router(s).
The format of the file is as follows:
The /etc/defaultrouter file can contain the IP
addresses or hostnames of one or more default routers, with each entry on
its own line. If you use hostnames, each hostname must also be listed in
the local /etc/hosts file, because no name services
are running at the time that defaultrouter is read.
Lines beginning with the ``#'' character are treated as comments.
The default routes listed in this file replace those added by the
kernel during diskless booting. An empty /etc/defaultrouter
file will cause the default route added by the kernel to be deleted.
Use of a default route, whether received from a DHCP
server or from /etc/defaultrouter, prevents a machine
from acting as an IPv4 router, even if that machine does not have an /etc/notrouter file.