/etc/network/interfaces文件为:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
auto dsl-provider
iface dsl-provider inet ppp
provider dsl-provider
# please do not modify the following line
pre-up /sbin/ifconfig eth1 up # line maintained by pppoeconf